toki: pona

Demonstrates pattern matching

Cargo.toml

@@ -8,14 +8,13 @@ members = [
     "compiler/cl-ast",
     "compiler/cl-parser",
     "compiler/cl-lexer",
-    "compiler/cl-arena",
     "repline",
 ]
 resolver = "2"
 
 [workspace.package]
 repository = "https://git.soft.fish/j/Conlang"
-version = "0.0.5"
+version = "0.0.9"
 authors = ["John Breaux <j@soft.fish>"]
 edition = "2021"
 license = "MIT"

compiler/cl-arena/Cargo.toml

@@ -1,10 +0,0 @@
-[package]
-name = "cl-arena"
-repository.workspace = true
-version.workspace = true
-authors.workspace = true
-edition.workspace = true
-license.workspace = true
-publish.workspace = true
-
-[dependencies]

compiler/cl-arena/src/dropless_arena/tests.rs

@@ -1,42 +0,0 @@
-use super::DroplessArena;
-    extern crate std;
-    use core::alloc::Layout;
-    use std::{prelude::rust_2021::*, vec};
-
-    #[test]
-    fn alloc_raw() {
-        let arena = DroplessArena::new();
-        let bytes = arena.alloc_raw(Layout::for_value(&0u128));
-        let byte2 = arena.alloc_raw(Layout::for_value(&0u128));
-
-        assert_ne!(bytes, byte2);
-    }
-
-    #[test]
-    fn alloc() {
-        let arena = DroplessArena::new();
-        let mut allocations = vec![];
-        for i in 0..0x400 {
-            allocations.push(arena.alloc(i));
-        }
-    }
-
-    #[test]
-    fn alloc_strings() {
-        const KW: &[&str] = &["pub", "mut", "fn", "mod", "conlang", "sidon", "🦈"];
-        let arena = DroplessArena::new();
-        let mut allocations = vec![];
-        for _ in 0..100 {
-            for kw in KW {
-                allocations.push(arena.alloc_str(kw));
-            }
-        }
-    }
-
-    #[test]
-    #[should_panic]
-    fn alloc_zsts() {
-        struct Zst;
-        let arena = DroplessArena::new();
-        arena.alloc(Zst);
-    }

compiler/cl-arena/src/lib.rs

@@ -1,396 +0,0 @@
-//! Typed and dropless arena allocation, paraphrased from [the Rust Compiler's `rustc_arena`](https://github.com/rust-lang/rust/blob/master/compiler/rustc_arena/src/lib.rs). See [LICENSE][1].
-//!
-//! An Arena Allocator is a type of allocator which provides stable locations for allocations within
-//! itself for the entire duration of its lifetime.
-//!
-//! [1]: https://raw.githubusercontent.com/rust-lang/rust/master/LICENSE-MIT
-
-#![feature(dropck_eyepatch, new_uninit, strict_provenance)]
-#![no_std]
-
-extern crate alloc;
-
-pub(crate) mod constants {
-    //! Size constants for arena chunk growth
-    pub(crate) const MIN_CHUNK: usize = 4096;
-    pub(crate) const MAX_CHUNK: usize = 2 * 1024 * 1024;
-}
-
-mod chunk {
-    //! An [ArenaChunk] contains a block of raw memory for use in arena allocators.
-    use alloc::boxed::Box;
-    use core::{
-        mem::{self, MaybeUninit},
-        ptr::{self, NonNull},
-    };
-
-    pub struct ArenaChunk<T> {
-        pub(crate) mem: NonNull<[MaybeUninit<T>]>,
-        pub(crate) filled: usize,
-    }
-
-    impl<T: Sized> ArenaChunk<T> {
-        pub fn new(cap: usize) -> Self {
-            let slice = Box::new_uninit_slice(cap);
-            Self { mem: NonNull::from(Box::leak(slice)), filled: 0 }
-        }
-
-        /// Drops all elements inside self, and resets the filled count to 0
-        ///
-        /// # Safety
-        ///
-        /// The caller must ensure that `self.filled` elements of self are currently initialized
-        pub unsafe fn drop_elements(&mut self) {
-            if mem::needs_drop::<T>() {
-                // Safety: the caller has ensured that `filled` elements are initialized
-                unsafe {
-                    let slice = self.mem.as_mut();
-                    for t in slice[..self.filled].iter_mut() {
-                        t.assume_init_drop();
-                    }
-                }
-                self.filled = 0;
-            }
-        }
-
-        /// Gets a pointer to the start of the arena
-        pub fn start(&mut self) -> *mut T {
-            self.mem.as_ptr() as _
-        }
-
-        /// Gets a pointer to the end of the arena
-        pub fn end(&mut self) -> *mut T {
-            if mem::size_of::<T>() == 0 {
-                ptr::without_provenance_mut(usize::MAX) // pointers to ZSTs must be unique
-            } else {
-                unsafe { self.start().add(self.mem.len()) }
-            }
-        }
-    }
-
-    impl<T> Drop for ArenaChunk<T> {
-        fn drop(&mut self) {
-            let _ = unsafe { Box::from_raw(self.mem.as_ptr()) };
-        }
-    }
-}
-
-pub mod typed_arena {
-    //! A [TypedArena] can hold many instances of a single type, and will properly [Drop] them.
-    #![allow(clippy::mut_from_ref)]
-
-    use crate::{chunk::ArenaChunk, constants::*};
-    use alloc::vec::Vec;
-    use core::{
-        cell::{Cell, RefCell},
-        marker::PhantomData,
-        mem, ptr, slice,
-    };
-
-    /// A [TypedArena] can hold many instances of a single type, and will properly [Drop] them when
-    /// it falls out of scope.
-    pub struct TypedArena<'arena, T> {
-        _lives: PhantomData<&'arena T>,
-        _drops: PhantomData<T>,
-        chunks: RefCell<Vec<ArenaChunk<T>>>,
-        head: Cell<*mut T>,
-        tail: Cell<*mut T>,
-    }
-
-    impl<'arena, T> Default for TypedArena<'arena, T> {
-        fn default() -> Self {
-            Self::new()
-        }
-    }
-
-    impl<'arena, T> TypedArena<'arena, T> {
-        pub const fn new() -> Self {
-            Self {
-                _lives: PhantomData,
-                _drops: PhantomData,
-                chunks: RefCell::new(Vec::new()),
-                head: Cell::new(ptr::null_mut()),
-                tail: Cell::new(ptr::null_mut()),
-            }
-        }
-
-        pub fn alloc(&'arena self, value: T) -> &'arena mut T {
-            if self.head == self.tail {
-                self.grow(1);
-            }
-
-            let out = if mem::size_of::<T>() == 0 {
-                self.head
-                    .set(ptr::without_provenance_mut(self.head.get().addr() + 1));
-                ptr::NonNull::<T>::dangling().as_ptr()
-            } else {
-                let out = self.head.get();
-                self.head.set(unsafe { out.add(1) });
-                out
-            };
-
-            unsafe {
-                ptr::write(out, value);
-                &mut *out
-            }
-        }
-
-        fn can_allocate(&self, len: usize) -> bool {
-            len <= unsafe { self.tail.get().offset_from(self.head.get()) as usize }
-        }
-
-        /// # Panics
-        /// Panics if size_of::<T> == 0 || len == 0
-        #[inline]
-        fn alloc_raw_slice(&self, len: usize) -> *mut T {
-            assert!(mem::size_of::<T>() != 0);
-            assert!(len != 0);
-
-            if !self.can_allocate(len) {
-                self.grow(len)
-            }
-
-            let out = self.head.get();
-
-            unsafe { self.head.set(out.add(len)) };
-            out
-        }
-
-        pub fn alloc_from_iter<I>(&'arena self, iter: I) -> &'arena mut [T]
-        where I: IntoIterator<Item = T> {
-            // Collect them all into a buffer so they're allocated contiguously
-            let mut buf = iter.into_iter().collect::<Vec<_>>();
-            if buf.is_empty() {
-                return &mut [];
-            }
-
-            let len = buf.len();
-            // If T is a ZST, calling alloc_raw_slice will panic
-            let slice = if mem::size_of::<T>() == 0 {
-                self.head
-                    .set(ptr::without_provenance_mut(self.head.get().addr() + len));
-                ptr::NonNull::dangling().as_ptr()
-            } else {
-                self.alloc_raw_slice(len)
-            };
-
-            unsafe {
-                buf.as_ptr().copy_to_nonoverlapping(slice, len);
-                buf.set_len(0);
-                slice::from_raw_parts_mut(slice, len)
-            }
-        }
-
-        #[cold]
-        #[inline(never)]
-        fn grow(&self, len: usize) {
-            let size = mem::size_of::<T>().max(1);
-
-            let mut chunks = self.chunks.borrow_mut();
-
-            let capacity = if let Some(last) = chunks.last_mut() {
-                last.filled = self.get_filled_of_chunk(last);
-                last.mem.len().min(MAX_CHUNK / size) * 2
-            } else {
-                MIN_CHUNK / size
-            }
-            .max(len);
-
-            let mut chunk = ArenaChunk::<T>::new(capacity);
-
-            self.head.set(chunk.start());
-            self.tail.set(chunk.end());
-            chunks.push(chunk);
-        }
-
-        fn get_filled_of_chunk(&self, chunk: &mut ArenaChunk<T>) -> usize {
-            let Self { head: tail, .. } = self;
-            let head = chunk.start();
-            if mem::size_of::<T>() == 0 {
-                tail.get().addr() - head.addr()
-            } else {
-                unsafe { tail.get().offset_from(head) as usize }
-            }
-        }
-    }
-
-    unsafe impl<'arena, T: Send> Send for TypedArena<'arena, T> {}
-
-    unsafe impl<'arena, #[may_dangle] T> Drop for TypedArena<'arena, T> {
-        fn drop(&mut self) {
-            let mut chunks = self.chunks.borrow_mut();
-
-            if let Some(last) = chunks.last_mut() {
-                last.filled = self.get_filled_of_chunk(last);
-                self.tail.set(self.head.get());
-            }
-
-            for chunk in chunks.iter_mut() {
-                unsafe { chunk.drop_elements() }
-            }
-        }
-    }
-
-    #[cfg(test)]
-    mod tests;
-}
-
-pub mod dropless_arena {
-    //! A [DroplessArena] can hold *any* combination of types as long as they don't implement
-    //! [Drop].
-    use crate::{chunk::ArenaChunk, constants::*};
-    use alloc::vec::Vec;
-    use core::{
-        alloc::Layout,
-        cell::{Cell, RefCell},
-        marker::PhantomData,
-        mem, ptr, slice,
-    };
-
-    pub struct DroplessArena<'arena> {
-        _lives: PhantomData<&'arena u8>,
-        chunks: RefCell<Vec<ArenaChunk<u8>>>,
-        head: Cell<*mut u8>,
-        tail: Cell<*mut u8>,
-    }
-
-    impl Default for DroplessArena<'_> {
-        fn default() -> Self {
-            Self::new()
-        }
-    }
-
-    impl<'arena> DroplessArena<'arena> {
-        pub const fn new() -> Self {
-            Self {
-                _lives: PhantomData,
-                chunks: RefCell::new(Vec::new()),
-                head: Cell::new(ptr::null_mut()),
-                tail: Cell::new(ptr::null_mut()),
-            }
-        }
-
-        /// Allocates a `T` in the [DroplessArena], and returns a mutable reference to it.
-        ///
-        /// # Panics
-        /// - Panics if T implements [Drop]
-        /// - Panics if T is zero-sized
-        #[allow(clippy::mut_from_ref)]
-        pub fn alloc<T>(&'arena self, value: T) -> &'arena mut T {
-            assert!(!mem::needs_drop::<T>());
-            assert!(mem::size_of::<T>() != 0);
-
-            let out = self.alloc_raw(Layout::new::<T>()) as *mut T;
-
-            unsafe {
-                ptr::write(out, value);
-                &mut *out
-            }
-        }
-
-        /// Allocates a slice of `T`s`, copied from the given slice, returning a mutable reference
-        /// to it.
-        ///
-        /// # Panics
-        /// - Panics if T implements [Drop]
-        /// - Panics if T is zero-sized
-        /// - Panics if the slice is empty
-        #[allow(clippy::mut_from_ref)]
-        pub fn alloc_slice<T: Copy>(&'arena self, slice: &[T]) -> &'arena mut [T] {
-            assert!(!mem::needs_drop::<T>());
-            assert!(mem::size_of::<T>() != 0);
-            assert!(!slice.is_empty());
-
-            let mem = self.alloc_raw(Layout::for_value::<[T]>(slice)) as *mut T;
-
-            unsafe {
-                mem.copy_from_nonoverlapping(slice.as_ptr(), slice.len());
-                slice::from_raw_parts_mut(mem, slice.len())
-            }
-        }
-
-        /// Allocates a copy of the given [`&str`](str), returning a reference to the allocation.
-        ///
-        /// # Panics
-        /// Panics if the string is empty.
-        pub fn alloc_str(&'arena self, string: &str) -> &'arena str {
-            let slice = self.alloc_slice(string.as_bytes());
-
-            // Safety: This is a clone of the input string, which was valid
-            unsafe { core::str::from_utf8_unchecked(slice) }
-        }
-
-        /// Allocates some [bytes](u8) based on the given [Layout].
-        ///
-        /// # Panics
-        /// Panics if the provided [Layout] has size 0
-        pub fn alloc_raw(&'arena self, layout: Layout) -> *mut u8 {
-            /// Rounds the given size (or pointer value) *up* to the given alignment
-            fn align_up(size: usize, align: usize) -> usize {
-                (size + align - 1) & !(align - 1)
-            }
-            /// Rounds the given size (or pointer value) *down* to the given alignment
-            fn align_down(size: usize, align: usize) -> usize {
-                size & !(align - 1)
-            }
-
-            assert!(layout.size() != 0);
-            loop {
-                let Self { head, tail, .. } = self;
-                let start = head.get().addr();
-                let end = tail.get().addr();
-
-                let align = 8.max(layout.align());
-
-                let bytes = align_up(layout.size(), align);
-
-                if let Some(end) = end.checked_sub(bytes) {
-                    let end = align_down(end, layout.align());
-
-                    if start <= end {
-                        tail.set(tail.get().with_addr(end));
-                        return tail.get();
-                    }
-                }
-
-                self.grow(layout.size());
-            }
-        }
-
-        /// Grows the allocator, doubling the chunk size until it reaches [MAX_CHUNK].
-        #[cold]
-        #[inline(never)]
-        fn grow(&self, len: usize) {
-            let mut chunks = self.chunks.borrow_mut();
-
-            let capacity = if let Some(last) = chunks.last_mut() {
-                last.mem.len().min(MAX_CHUNK / 2) * 2
-            } else {
-                MIN_CHUNK
-            }
-            .max(len);
-
-            let mut chunk = ArenaChunk::<u8>::new(capacity);
-
-            self.head.set(chunk.start());
-            self.tail.set(chunk.end());
-            chunks.push(chunk);
-        }
-
-        /// Checks whether the given slice is allocated in this arena
-        pub fn contains_slice<T>(&self, slice: &[T]) -> bool {
-            let ptr = slice.as_ptr().cast::<u8>().cast_mut();
-            for chunk in self.chunks.borrow_mut().iter_mut() {
-                if chunk.start() <= ptr && ptr <= chunk.end() {
-                    return true;
-                }
-            }
-            false
-        }
-    }
-
-    unsafe impl<'arena> Send for DroplessArena<'arena> {}
-
-    #[cfg(test)]
-    mod tests;
-}

compiler/cl-arena/src/typed_arena/tests.rs

@@ -1,61 +0,0 @@
-use super::TypedArena;
-    extern crate std;
-    use std::{prelude::rust_2021::*, print, vec};
-    #[test]
-    fn pushing_to_arena() {
-        let arena = TypedArena::new();
-        let foo = arena.alloc("foo");
-        let bar = arena.alloc("bar");
-        let baz = arena.alloc("baz");
-
-        assert_eq!("foo", *foo);
-        assert_eq!("bar", *bar);
-        assert_eq!("baz", *baz);
-    }
-
-    #[test]
-    fn pushing_vecs_to_arena() {
-        let arena = TypedArena::new();
-
-        let foo = arena.alloc(vec!["foo"]);
-        let bar = arena.alloc(vec!["bar"]);
-        let baz = arena.alloc(vec!["baz"]);
-
-        assert_eq!("foo", foo[0]);
-        assert_eq!("bar", bar[0]);
-        assert_eq!("baz", baz[0]);
-    }
-
-    #[test]
-    fn pushing_zsts() {
-        struct ZeroSized;
-        impl Drop for ZeroSized {
-            fn drop(&mut self) {
-                print!("")
-            }
-        }
-
-        let arena = TypedArena::new();
-
-        for _ in 0..0x100 {
-            arena.alloc(ZeroSized);
-        }
-    }
-
-    #[test]
-    fn pushing_nodrop_zsts() {
-        struct ZeroSized;
-        let arena = TypedArena::new();
-
-        for _ in 0..0x1000 {
-            arena.alloc(ZeroSized);
-        }
-    }
-    #[test]
-    fn resize() {
-        let arena = TypedArena::new();
-
-        for _ in 0..0x780 {
-            arena.alloc(0u128);
-        }
-    }

compiler/cl-ast/src/ast.rs

@@ -8,6 +8,7 @@
 //!   - [Assign], [Modify], [Binary], and [Unary] expressions
 //!   - [ModifyKind], [BinaryKind], and [UnaryKind] operators
 //! - [Ty] and [TyKind]: Type qualifiers
+//! - [Pattern]: Pattern matching operators
 //! - [Path]: Path expressions
 use cl_structures::{intern::interned::Interned, span::*};
 
@@ -36,6 +37,7 @@ pub enum Literal {
     Bool(bool),
     Char(char),
     Int(u128),
+    Float(u64),
     String(String),
 }
 
@@ -79,7 +81,6 @@ pub struct Item {
 /// What kind of [Item] is this?
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub enum ItemKind {
-    // TODO: Import declaration ("use") item
     // TODO: Trait declaration ("trait") item?
     /// A [module](Module)
     Module(Module),
@@ -258,7 +259,6 @@ pub enum TyKind {
     Tuple(TyTuple),
     Ref(TyRef),
     Fn(TyFn),
-    // TODO: slice, array types
 }
 
 /// An array of [`T`](Ty)
@@ -323,7 +323,6 @@ pub struct Stmt {
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub enum StmtKind {
     Empty,
-    Local(Let),
     Item(Box<Item>),
     Expr(Box<Expr>),
 }
@@ -335,15 +334,6 @@ pub enum Semi {
     Unterminated,
 }
 
-/// A local variable declaration [Stmt]
-#[derive(Clone, Debug, PartialEq, Eq, Hash)]
-pub struct Let {
-    pub mutable: Mutability,
-    pub name: Sym,
-    pub ty: Option<Box<Ty>>,
-    pub init: Option<Box<Expr>>,
-}
-
 /// An expression, the beating heart of the language
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub struct Expr {
@@ -357,6 +347,12 @@ pub enum ExprKind {
     /// An empty expression: `(` `)`
     #[default]
     Empty,
+    /// A backtick-quoted expression
+    Quote(Quote),
+    /// A local bind instruction, `let` [`Sym`] `=` [`Expr`]
+    Let(Let),
+    /// A [Match] expression: `match` [Expr] `{` ([MatchArm] `,`)* [MatchArm]? `}`
+    Match(Match),
     /// An [Assign]ment expression: [`Expr`] (`=` [`Expr`])\+
     Assign(Assign),
     /// A [Modify]-assignment expression: [`Expr`] ([`ModifyKind`] [`Expr`])\+
@@ -365,6 +361,8 @@ pub enum ExprKind {
     Binary(Binary),
     /// A [Unary] expression: [`UnaryKind`]\* [`Expr`]
     Unary(Unary),
+    /// A [Cast] expression: [`Expr`] `as` [`Ty`]
+    Cast(Cast),
     /// A [Member] access expression: [`Expr`] [`MemberKind`]\*
     Member(Member),
     /// An Array [Index] expression: a[10, 20, 30]
@@ -388,8 +386,6 @@ pub enum ExprKind {
     Group(Group),
     /// A [Tuple] expression: `(` [`Expr`] (`,` [`Expr`])+ `)`
     Tuple(Tuple),
-    /// A [Loop] expression: `loop` [`Block`]
-    Loop(Loop),
     /// A [While] expression: `while` [`Expr`] [`Block`] [`Else`]?
     While(While),
     /// An [If] expression: `if` [`Expr`] [`Block`] [`Else`]?
@@ -401,9 +397,46 @@ pub enum ExprKind {
     /// A [Return] expression `return` [`Expr`]?
     Return(Return),
     /// A continue expression: `continue`
-    Continue(Continue),
+    Continue,
 }
 
+/// A backtick-quoted subexpression-literal
+#[derive(Clone, Debug, PartialEq, Eq, Hash)]
+pub struct Quote {
+    pub quote: Box<ExprKind>,
+}
+
+/// A local variable declaration [Stmt]
+#[derive(Clone, Debug, PartialEq, Eq, Hash)]
+pub struct Let {
+    pub mutable: Mutability,
+    pub name: Pattern,
+    pub ty: Option<Box<Ty>>,
+    pub init: Option<Box<Expr>>,
+}
+
+/// A [Pattern] meta-expression (any [`ExprKind`] that fits pattern rules)
+#[derive(Clone, Debug, PartialEq, Eq, Hash)]
+pub enum Pattern {
+    Path(Path),
+    Literal(Literal),
+    Ref(Mutability, Box<Pattern>),
+    Tuple(Vec<Pattern>),
+    Array(Vec<Pattern>),
+    Struct(Path, Vec<(Path, Option<Pattern>)>),
+}
+
+/// A `match` expression: `match` `{` ([MatchArm] `,`)* [MatchArm]? `}`
+#[derive(Clone, Debug, PartialEq, Eq, Hash)]
+pub struct Match {
+    pub scrutinee: Box<Expr>,
+    pub arms: Vec<MatchArm>,
+}
+
+/// A single arm of a [Match] expression: [`Pattern`] `=>` [`Expr`]
+#[derive(Clone, Debug, PartialEq, Eq, Hash)]
+pub struct MatchArm(pub Pattern, pub Expr);
+
 /// An [Assign]ment expression: [`Expr`] ([`ModifyKind`] [`Expr`])\+
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub struct Assign {
@@ -478,12 +511,21 @@ pub enum UnaryKind {
     Deref,
     Neg,
     Not,
+    /// A Loop expression: `loop` [`Block`]
+    Loop,
     /// Unused
     At,
     /// Unused
     Tilde,
 }
 
+/// A cast expression: [`Expr`] `as` [`Ty`]
+#[derive(Clone, Debug, PartialEq, Eq, Hash)]
+pub struct Cast {
+    pub head: Box<ExprKind>,
+    pub ty: Ty,
+}
+
 /// A [Member] access expression: [`Expr`] [`MemberKind`]\*
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub struct Member {
@@ -537,7 +579,6 @@ pub struct ArrayRep {
 /// An address-of expression: `&` `mut`? [`Expr`]
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub struct AddrOf {
-    pub count: usize,
     pub mutable: Mutability,
     pub expr: Box<ExprKind>,
 }
@@ -560,12 +601,6 @@ pub struct Tuple {
     pub exprs: Vec<Expr>,
 }
 
-/// A [Loop] expression: `loop` [`Block`]
-#[derive(Clone, Debug, PartialEq, Eq, Hash)]
-pub struct Loop {
-    pub body: Box<Expr>,
-}
-
 /// A [While] expression: `while` [`Expr`] [`Block`] [`Else`]?
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub struct While {
@@ -608,7 +643,3 @@ pub struct Break {
 pub struct Return {
     pub body: Option<Box<Expr>>,
 }
-
-/// A continue expression: `continue`
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Hash)]
-pub struct Continue;

compiler/cl-ast/src/ast_impl.rs

@@ -9,8 +9,24 @@ mod display {
     use std::{
         borrow::Borrow,
         fmt::{Display, Write},
+        io::IsTerminal,
     };
 
+    fn keyword(d: impl Display, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        if std::io::stdout().is_terminal() {
+            write!(f, "\x1b[31m{d}\x1b[0m")
+        } else {
+            d.fmt(f)
+        }
+    }
+    fn ident(d: impl Display, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        if std::io::stdout().is_terminal() {
+            write!(f, "\x1b[95m{d}\x1b[0m")
+        } else {
+            d.fmt(f)
+        }
+    }
+
     fn separate<I: Display, W: Write>(
         iterable: impl IntoIterator<Item = I>,
         sep: &'static str,
@@ -30,7 +46,7 @@ mod display {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             match self {
                 Mutability::Not => Ok(()),
-                Mutability::Mut => "mut ".fmt(f),
+                Mutability::Mut => keyword("ante ", f),
             }
         }
     }
@@ -39,18 +55,28 @@ mod display {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             match self {
                 Visibility::Private => Ok(()),
-                Visibility::Public => "pub ".fmt(f),
+                Visibility::Public => keyword("lukin ", f),
             }
         }
     }
 
     impl Display for Literal {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-            match self {
-                Literal::Bool(v) => v.fmt(f),
-                Literal::Char(v) => write!(f, "'{v}'"),
-                Literal::Int(v) => v.fmt(f),
-                Literal::String(v) => write!(f, "\"{v}\""),
+            fn fmt(this: &Literal, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+                match this {
+                    Literal::Bool(v) => v.fmt(f),
+                    Literal::Char(v) => write!(f, "'{}'", v.escape_debug()),
+                    Literal::Int(v) => v.fmt(f),
+                    Literal::Float(v) => write!(f, "{:?}", f64::from_bits(*v)),
+                    Literal::String(v) => write!(f, "\"{}\"", v.escape_debug()),
+                }
+            }
+            if std::io::stdout().is_terminal() {
+                write!(f, "\x1b[94m")?;
+                fmt(self, f)?;
+                write!(f, "\x1b[0m")
+            } else {
+                fmt(self, f)
             }
         }
     }
@@ -76,7 +102,8 @@ mod display {
     impl Display for Meta {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             let Self { name, kind } = self;
-            write!(f, "{name}{kind}")
+            ident(name, f)?;
+            write!(f, "{kind}")
         }
     }
 
@@ -118,9 +145,10 @@ mod display {
     impl Display for Alias {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             let Self { to, from } = self;
+            keyword("ijo", f)?;
             match from {
-                Some(from) => write!(f, "type {to} = {from};"),
-                None => write!(f, "type {to};"),
+                Some(from) => write!(f, " {to} = {from};"),
+                None => write!(f, " {to};"),
             }
         }
     }
@@ -128,21 +156,28 @@ mod display {
     impl Display for Const {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             let Self { name, ty, init } = self;
-            write!(f, "const {name}: {ty} = {init}")
+            keyword("kiwen ", f)?;
+            ident(name, f)?;
+            write!(f, ": {ty} = {init}")
         }
     }
 
     impl Display for Static {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             let Self { mutable, name, ty, init } = self;
-            write!(f, "static {mutable}{name}: {ty} = {init}")
+            keyword("mute", f)?;
+            write!(f, " {mutable}")?;
+            ident(name, f)?;
+            write!(f, ": {ty} = {init}")
         }
     }
 
     impl Display for Module {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             let Self { name, kind } = self;
-            write!(f, "mod {name}{kind}")
+            keyword("selo ", f)?;
+            ident(name, f)?;
+            write!(f, "{kind}")
         }
     }
 
@@ -171,7 +206,10 @@ mod display {
             };
 
             debug_assert_eq!(bind.len(), types.len());
-            write!(f, "fn {name} ")?;
+            keyword("nasin", f)?;
+            " ".fmt(f)?;
+            ident(name, f)?;
+            " ".fmt(f)?;
             {
                 let mut f = f.delimit(INLINE_PARENS);
                 for (idx, (arg, ty)) in bind.iter().zip(types.iter()).enumerate() {
@@ -194,14 +232,17 @@ mod display {
     impl Display for Param {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             let Self { mutability, name } = self;
-            write!(f, "{mutability}{name}")
+            write!(f, "{mutability}")?;
+            ident(name, f)
         }
     }
 
     impl Display for Struct {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             let Self { name, kind } = self;
-            write!(f, "struct {name}{kind}")
+            keyword("lipu ", f)?;
+            ident(name, f)?;
+            write!(f, "{kind}")
         }
     }
 
@@ -218,14 +259,18 @@ mod display {
     impl Display for StructMember {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             let Self { vis, name, ty } = self;
-            write!(f, "{vis}{name}: {ty}")
+            write!(f, "{vis}")?;
+            ident(name, f)?;
+            write!(f, ": {ty}")
         }
     }
 
     impl Display for Enum {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             let Self { name, kind } = self;
-            write!(f, "enum {name}{kind}")
+            keyword("kulupu ", f)?;
+            ident(name, f)?;
+            write!(f, "{kind}")
         }
     }
 
@@ -241,7 +286,8 @@ mod display {
     impl Display for Variant {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             let Self { name, kind } = self;
-            write!(f, "{name}{kind}")
+            ident(name, f)?;
+            write!(f, "{kind}")
         }
     }
 
@@ -259,7 +305,8 @@ mod display {
     impl Display for Impl {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             let Self { target, body } = self;
-            write!(f, "impl {target} ")?;
+            keyword("insa", f)?;
+            write!(f, " {target} ")?;
             write!(f.delimit(BRACES), "{body}")
         }
     }
@@ -269,7 +316,9 @@ mod display {
             match self {
                 ImplKind::Type(t) => t.fmt(f),
                 ImplKind::Trait { impl_trait, for_type } => {
-                    write!(f, "{impl_trait} for {for_type}")
+                    write!(f, "{impl_trait} ")?;
+                    keyword("ale", f)?;
+                    write!(f, " {for_type}")
                 }
             }
         }
@@ -278,7 +327,8 @@ mod display {
     impl Display for Use {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             let Self { absolute, tree } = self;
-            f.write_str(if *absolute { "use ::" } else { "use " })?;
+            keyword("jo", f)?;
+            f.write_str(if *absolute { " ::" } else { " " })?;
             write!(f, "{tree};")
         }
     }
@@ -288,8 +338,12 @@ mod display {
             match self {
                 UseTree::Tree(tree) => separate(tree, ", ")(f.delimit(INLINE_BRACES)),
                 UseTree::Path(path, rest) => write!(f, "{path}::{rest}"),
-                UseTree::Alias(path, name) => write!(f, "{path} as {name}"),
-                UseTree::Name(name) => write!(f, "{name}"),
+                UseTree::Alias(path, name) => {
+                    write!(f, "{path} ")?;
+                    keyword("sama ", f)?;
+                    ident(name, f)
+                }
+                UseTree::Name(name) => ident(name, f),
                 UseTree::Glob => write!(f, "*"),
             }
         }
@@ -349,7 +403,8 @@ mod display {
     impl Display for TyFn {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             let Self { args, rety } = self;
-            write!(f, "fn {args}")?;
+            keyword("nasin", f)?;
+            write!(f, " {args}")?;
             match rety {
                 Some(v) => write!(f, " -> {v}"),
                 None => Ok(()),
@@ -370,10 +425,10 @@ mod display {
     impl Display for PathPart {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             match self {
-                PathPart::SuperKw => "super".fmt(f),
-                PathPart::SelfKw => "self".fmt(f),
-                PathPart::SelfTy => "Self".fmt(f),
-                PathPart::Ident(id) => id.fmt(f),
+                PathPart::SuperKw => keyword("mama", f),
+                PathPart::SelfKw => keyword("mi", f),
+                PathPart::SelfTy => keyword("Mi", f),
+                PathPart::Ident(id) => ident(id, f),
             }
         }
     }
@@ -389,7 +444,6 @@ mod display {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             match self {
                 StmtKind::Empty => Ok(()),
-                StmtKind::Local(v) => v.fmt(f),
                 StmtKind::Item(v) => v.fmt(f),
                 StmtKind::Expr(v) => v.fmt(f),
             }
@@ -405,20 +459,6 @@ mod display {
         }
     }
 
-    impl Display for Let {
-        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-            let Self { mutable, name, ty, init } = self;
-            write!(f, "let {mutable}{name}")?;
-            if let Some(value) = ty {
-                write!(f, ": {value}")?;
-            }
-            if let Some(value) = init {
-                write!(f, " = {value}")?;
-            }
-            Ok(())
-        }
-    }
-
     impl Display for Expr {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             self.kind.fmt(f)
@@ -429,10 +469,14 @@ mod display {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             match self {
                 ExprKind::Empty => "()".fmt(f),
+                ExprKind::Quote(v) => v.fmt(f),
+                ExprKind::Let(v) => v.fmt(f),
+                ExprKind::Match(v) => v.fmt(f),
                 ExprKind::Assign(v) => v.fmt(f),
                 ExprKind::Modify(v) => v.fmt(f),
                 ExprKind::Binary(v) => v.fmt(f),
                 ExprKind::Unary(v) => v.fmt(f),
+                ExprKind::Cast(v) => v.fmt(f),
                 ExprKind::Member(v) => v.fmt(f),
                 ExprKind::Index(v) => v.fmt(f),
                 ExprKind::Structor(v) => v.fmt(f),
@@ -444,17 +488,82 @@ mod display {
                 ExprKind::Block(v) => v.fmt(f),
                 ExprKind::Group(v) => v.fmt(f),
                 ExprKind::Tuple(v) => v.fmt(f),
-                ExprKind::Loop(v) => v.fmt(f),
                 ExprKind::While(v) => v.fmt(f),
                 ExprKind::If(v) => v.fmt(f),
                 ExprKind::For(v) => v.fmt(f),
                 ExprKind::Break(v) => v.fmt(f),
                 ExprKind::Return(v) => v.fmt(f),
-                ExprKind::Continue(_) => "continue".fmt(f),
+                ExprKind::Continue => keyword("tama", f),
             }
         }
     }
 
+    impl Display for Quote {
+        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+            let Self { quote } = self;
+            write!(f, "`{quote}`")
+        }
+    }
+
+    impl Display for Let {
+        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+            let Self { mutable, name, ty, init } = self;
+            keyword("poki", f)?;
+            write!(f, " {mutable}")?;
+            ident(name, f)?;
+
+            if let Some(value) = ty {
+                write!(f, ": {value}")?;
+            }
+            if let Some(value) = init {
+                write!(f, " = {value}")?;
+            }
+            Ok(())
+        }
+    }
+
+    impl Display for Pattern {
+        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+            match self {
+                Pattern::Path(path) => path.fmt(f),
+                Pattern::Literal(literal) => literal.fmt(f),
+                Pattern::Ref(mutability, pattern) => write!(f, "&{mutability}{pattern}"),
+                Pattern::Tuple(patterns) => separate(patterns, ", ")(f.delimit(INLINE_PARENS)),
+                Pattern::Array(patterns) => separate(patterns, ", ")(f.delimit(INLINE_SQUARE)),
+                Pattern::Struct(path, items) => {
+                    write!(f, "{path}: ")?;
+                    let f = &mut f.delimit(BRACES);
+                    for (idx, (name, item)) in items.iter().enumerate() {
+                        if idx != 0 {
+                            f.write_str(",\n")?;
+                        }
+                        write!(f, "{name}")?;
+                        if let Some(pattern) = item {
+                            write!(f, ": {pattern}")?
+                        }
+                    }
+                    Ok(())
+                }
+            }
+        }
+    }
+
+    impl Display for Match {
+        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+            let Self { scrutinee, arms } = self;
+            keyword("seme", f)?;
+            write!(f, " {scrutinee} ")?;
+            separate(arms, ",\n")(f.delimit(BRACES))
+        }
+    }
+
+    impl Display for MatchArm {
+        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+            let Self(pat, expr) = self;
+            write!(f, "{pat} => {expr}")
+        }
+    }
+
     impl Display for Assign {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             let Self { parts } = self;
@@ -538,6 +647,7 @@ mod display {
     impl Display for UnaryKind {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             match self {
+                UnaryKind::Loop => return keyword("awen ", f),
                 UnaryKind::Deref => "*",
                 UnaryKind::Neg => "-",
                 UnaryKind::Not => "!",
@@ -548,6 +658,15 @@ mod display {
         }
     }
 
+    impl Display for Cast {
+        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+            let Self { head, ty } = self;
+            write!(f, "{head} ")?;
+            keyword("sama", f)?;
+            write!(f, " {ty}")
+        }
+    }
+
     impl Display for Member {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             let Self { head, kind } = self;
@@ -558,9 +677,12 @@ mod display {
     impl Display for MemberKind {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             match self {
-                MemberKind::Call(name, args) => write!(f, "{name}{args}"),
-                MemberKind::Struct(name) => write!(f, "{name}"),
-                MemberKind::Tuple(name) => write!(f, "{name}"),
+                MemberKind::Call(name, args) => {
+                    ident(name, f)?;
+                    separate(&args.exprs, ", ")(f.delimit(INLINE_PARENS))
+                }
+                MemberKind::Struct(name) => ident(name, f),
+                MemberKind::Tuple(name) => ident(name, f),
             }
         }
     }
@@ -584,7 +706,7 @@ mod display {
     impl Display for Fielder {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             let Self { name, init } = self;
-            write!(f, "{name}")?;
+            ident(name, f)?;
             if let Some(init) = init {
                 write!(f, ": {init}")?;
             }
@@ -607,17 +729,19 @@ mod display {
 
     impl Display for AddrOf {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-            let Self { count, mutable, expr } = self;
-            for _ in 0..*count {
-                f.write_char('&')?;
-            }
-            write!(f, "{mutable}{expr}")
+            let Self { mutable, expr } = self;
+            write!(f, "&{mutable}{expr}")
         }
     }
 
     impl Display for Block {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-            separate(&self.stmts, "\n")(f.delimit(BRACES))
+            let Self { stmts } = self;
+
+            match stmts.as_slice() {
+                [] => "{}".fmt(f),
+                stmts => separate(stmts, "\n")(f.delimit(BRACES)),
+            }
         }
     }
 
@@ -629,42 +753,48 @@ mod display {
 
     impl Display for Tuple {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-            separate(&self.exprs, ", ")(f.delimit(INLINE_PARENS))
-        }
-    }
+            let Self { exprs } = self;
 
-    impl Display for Loop {
-        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-            let Self { body } = self;
-            write!(f, "loop {body}")
+            match exprs.as_slice() {
+                [] => write!(f, "()"),
+                [expr] => write!(f, "({expr},)"),
+                exprs => separate(exprs, ", ")(f.delimit(INLINE_PARENS)),
+            }
         }
     }
 
     impl Display for While {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             let Self { cond, pass, fail } = self;
-            write!(f, "while {cond} {pass}{fail}")
+            write!(f, "lawa {cond} {pass}{fail}")
         }
     }
 
     impl Display for If {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             let Self { cond, pass, fail } = self;
-            write!(f, "if {cond} {pass}{fail}")
+            keyword("tan", f)?;
+            write!(f, " {cond} {pass}{fail}")
         }
     }
 
     impl Display for For {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             let Self { bind, cond, pass, fail } = self;
-            write!(f, "for {bind} in {cond} {pass}{fail}")
+            keyword("ale", f)?;
+            write!(f, " {bind} ")?;
+            keyword("lon", f)?;
+            write!(f, " {cond} {pass}{fail}")
         }
     }
 
     impl Display for Else {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             match &self.body {
-                Some(body) => write!(f, " else {body}"),
+                Some(body) => {
+                    keyword(" taso", f)?;
+                    write!(f, " {body}")
+                }
                 _ => Ok(()),
             }
         }
@@ -672,7 +802,7 @@ mod display {
 
     impl Display for Break {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-            write!(f, "break")?;
+            keyword("pana", f)?;
             match &self.body {
                 Some(body) => write!(f, " {body}"),
                 _ => Ok(()),
@@ -682,19 +812,13 @@ mod display {
 
     impl Display for Return {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-            write!(f, "return")?;
+            keyword("pini", f)?;
             match &self.body {
                 Some(body) => write!(f, " {body}"),
                 _ => Ok(()),
             }
         }
     }
-
-    impl Display for Continue {
-        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-            "continue".fmt(f)
-        }
-    }
 }
 
 mod convert {
@@ -755,15 +879,18 @@ mod convert {
             TyFn => TyKind::Fn,
         }
         impl From for StmtKind {
-            Let => StmtKind::Local,
             Item => StmtKind::Item,
             Expr => StmtKind::Expr,
         }
         impl From for ExprKind {
+            Let => ExprKind::Let,
+            Quote => ExprKind::Quote,
+            Match => ExprKind::Match,
             Assign => ExprKind::Assign,
             Modify => ExprKind::Modify,
             Binary => ExprKind::Binary,
             Unary => ExprKind::Unary,
+            Cast => ExprKind::Cast,
             Member => ExprKind::Member,
             Index => ExprKind::Index,
             Path => ExprKind::Path,
@@ -774,13 +901,11 @@ mod convert {
             Block => ExprKind::Block,
             Group => ExprKind::Group,
             Tuple => ExprKind::Tuple,
-            Loop => ExprKind::Loop,
             While => ExprKind::While,
             If => ExprKind::If,
             For => ExprKind::For,
             Break => ExprKind::Break,
             Return => ExprKind::Return,
-            Continue => ExprKind::Continue,
         }
         impl From for Literal {
             bool => Literal::Bool,
@@ -800,6 +925,50 @@ mod convert {
             Self { body: Some(value.into()) }
         }
     }
+
+    impl TryFrom<ExprKind> for Pattern {
+        type Error = ExprKind;
+
+        /// Performs the conversion. On failure, returns the *first* non-pattern subexpression.
+        fn try_from(value: ExprKind) -> Result<Self, Self::Error> {
+            Ok(match value {
+                ExprKind::Literal(literal) => Pattern::Literal(literal),
+                ExprKind::Path(path) => Pattern::Path(path),
+                ExprKind::Empty => Pattern::Tuple(vec![]),
+                ExprKind::Group(Group { expr }) => Pattern::Tuple(vec![Pattern::try_from(*expr)?]),
+                ExprKind::Tuple(Tuple { exprs }) => Pattern::Tuple(
+                    exprs
+                        .into_iter()
+                        .map(|e| Pattern::try_from(e.kind))
+                        .collect::<Result<_, _>>()?,
+                ),
+                ExprKind::AddrOf(AddrOf { mutable, expr }) => {
+                    Pattern::Ref(mutable, Box::new(Pattern::try_from(*expr)?))
+                }
+                ExprKind::Array(Array { values }) => Pattern::Array(
+                    values
+                        .into_iter()
+                        .map(|e| Pattern::try_from(e.kind))
+                        .collect::<Result<_, _>>()?,
+                ),
+                // ExprKind::Index(index) => todo!(),
+                // ExprKind::Member(member) => todo!(),
+                ExprKind::Structor(Structor { to, init }) => {
+                    let fields = init
+                        .into_iter()
+                        .map(|Fielder { name, init }| {
+                            Ok((
+                                name.into(),
+                                init.map(|i| Pattern::try_from(i.kind)).transpose()?,
+                            ))
+                        })
+                        .collect::<Result<_, Self::Error>>()?;
+                    Pattern::Struct(to, fields)
+                }
+                err => Err(err)?,
+            })
+        }
+    }
 }
 
 mod path {
@@ -825,10 +994,26 @@ mod path {
                 self
             }
         }
+
+        /// Checks whether this path refers to the sinkhole identifier, `_`
+        pub fn is_sinkhole(&self) -> bool {
+            if let [PathPart::Ident(id)] = self.parts.as_slice() {
+                if let "_" = Sym::to_ref(id) {
+                    return true;
+                }
+            }
+            false
+        }
     }
     impl PathPart {
         pub fn from_sym(ident: Sym) -> Self {
             Self::Ident(ident)
         }
     }
+
+    impl From<Sym> for Path {
+        fn from(value: Sym) -> Self {
+            Self { parts: vec![PathPart::Ident(value)], absolute: false }
+        }
+    }
 }

compiler/cl-ast/src/ast_visitor/fold.rs

@@ -37,6 +37,9 @@ pub trait Fold {
     fn fold_int(&mut self, i: u128) -> u128 {
         i
     }
+    fn fold_smuggled_float(&mut self, f: u64) -> u64 {
+        f
+    }
     fn fold_string(&mut self, s: String) -> String {
         s
     }
@@ -226,15 +229,6 @@ pub trait Fold {
     fn fold_semi(&mut self, s: Semi) -> Semi {
         s
     }
-    fn fold_let(&mut self, l: Let) -> Let {
-        let Let { mutable, name, ty, init } = l;
-        Let {
-            mutable: self.fold_mutability(mutable),
-            name: self.fold_sym(name),
-            ty: ty.map(|t| Box::new(self.fold_ty(*t))),
-            init: init.map(|e| Box::new(self.fold_expr(*e))),
-        }
-    }
     fn fold_expr(&mut self, e: Expr) -> Expr {
         let Expr { extents, kind } = e;
         Expr { extents: self.fold_span(extents), kind: self.fold_expr_kind(kind) }
@@ -242,6 +236,56 @@ pub trait Fold {
     fn fold_expr_kind(&mut self, kind: ExprKind) -> ExprKind {
         or_fold_expr_kind(self, kind)
     }
+    fn fold_let(&mut self, l: Let) -> Let {
+        let Let { mutable, name, ty, init } = l;
+        Let {
+            mutable: self.fold_mutability(mutable),
+            name: self.fold_pattern(name),
+            ty: ty.map(|t| Box::new(self.fold_ty(*t))),
+            init: init.map(|e| Box::new(self.fold_expr(*e))),
+        }
+    }
+
+    fn fold_pattern(&mut self, p: Pattern) -> Pattern {
+        match p {
+            Pattern::Path(path) => Pattern::Path(self.fold_path(path)),
+            Pattern::Literal(literal) => Pattern::Literal(self.fold_literal(literal)),
+            Pattern::Ref(mutability, pattern) => Pattern::Ref(
+                self.fold_mutability(mutability),
+                Box::new(self.fold_pattern(*pattern)),
+            ),
+            Pattern::Tuple(patterns) => {
+                Pattern::Tuple(patterns.into_iter().map(|p| self.fold_pattern(p)).collect())
+            }
+            Pattern::Array(patterns) => {
+                Pattern::Array(patterns.into_iter().map(|p| self.fold_pattern(p)).collect())
+            }
+            Pattern::Struct(path, items) => Pattern::Struct(
+                self.fold_path(path),
+                items
+                    .into_iter()
+                    .map(|(name, bind)| (name, bind.map(|p| self.fold_pattern(p))))
+                    .collect(),
+            ),
+        }
+    }
+
+    fn fold_match(&mut self, m: Match) -> Match {
+        let Match { scrutinee, arms } = m;
+        Match {
+            scrutinee: self.fold_expr(*scrutinee).into(),
+            arms: arms
+                .into_iter()
+                .map(|arm| self.fold_match_arm(arm))
+                .collect(),
+        }
+    }
+
+    fn fold_match_arm(&mut self, a: MatchArm) -> MatchArm {
+        let MatchArm(pat, expr) = a;
+        MatchArm(self.fold_pattern(pat), self.fold_expr(expr))
+    }
+    
     fn fold_assign(&mut self, a: Assign) -> Assign {
         let Assign { parts } = a;
         let (head, tail) = *parts;
@@ -276,6 +320,10 @@ pub trait Fold {
     fn fold_unary_kind(&mut self, kind: UnaryKind) -> UnaryKind {
         kind
     }
+    fn fold_cast(&mut self, cast: Cast) -> Cast {
+        let Cast { head, ty } = cast;
+        Cast { head: Box::new(self.fold_expr_kind(*head)), ty: self.fold_ty(ty) }
+    }
     fn fold_member(&mut self, m: Member) -> Member {
         let Member { head, kind } = m;
         Member { head: Box::new(self.fold_expr_kind(*head)), kind: self.fold_member_kind(kind) }
@@ -315,9 +363,8 @@ pub trait Fold {
         }
     }
     fn fold_addrof(&mut self, a: AddrOf) -> AddrOf {
-        let AddrOf { count, mutable, expr } = a;
+        let AddrOf { mutable, expr } = a;
         AddrOf {
-            count,
             mutable: self.fold_mutability(mutable),
             expr: Box::new(self.fold_expr_kind(*expr)),
         }
@@ -334,10 +381,6 @@ pub trait Fold {
         let Tuple { exprs } = t;
         Tuple { exprs: exprs.into_iter().map(|e| self.fold_expr(e)).collect() }
     }
-    fn fold_loop(&mut self, l: Loop) -> Loop {
-        let Loop { body } = l;
-        Loop { body: Box::new(self.fold_expr(*body)) }
-    }
     fn fold_while(&mut self, w: While) -> While {
         let While { cond, pass, fail } = w;
         While {
@@ -375,10 +418,6 @@ pub trait Fold {
         let Return { body } = r;
         Return { body: body.map(|e| Box::new(self.fold_expr(*e))) }
     }
-    fn fold_continue(&mut self, c: Continue) -> Continue {
-        let Continue = c;
-        Continue
-    }
 }
 
 #[inline]
@@ -388,6 +427,7 @@ pub fn or_fold_literal<F: Fold + ?Sized>(folder: &mut F, lit: Literal) -> Litera
         Literal::Bool(b) => Literal::Bool(folder.fold_bool(b)),
         Literal::Char(c) => Literal::Char(folder.fold_char(c)),
         Literal::Int(i) => Literal::Int(folder.fold_int(i)),
+        Literal::Float(f) => Literal::Float(folder.fold_smuggled_float(f)),
         Literal::String(s) => Literal::String(folder.fold_string(s)),
     }
 }
@@ -521,7 +561,6 @@ pub fn or_fold_ty_kind<F: Fold + ?Sized>(folder: &mut F, kind: TyKind) -> TyKind
 pub fn or_fold_stmt_kind<F: Fold + ?Sized>(folder: &mut F, kind: StmtKind) -> StmtKind {
     match kind {
         StmtKind::Empty => StmtKind::Empty,
-        StmtKind::Local(l) => StmtKind::Local(folder.fold_let(l)),
         StmtKind::Item(i) => StmtKind::Item(Box::new(folder.fold_item(*i))),
         StmtKind::Expr(e) => StmtKind::Expr(Box::new(folder.fold_expr(*e))),
     }
@@ -531,10 +570,14 @@ pub fn or_fold_stmt_kind<F: Fold + ?Sized>(folder: &mut F, kind: StmtKind) -> St
 pub fn or_fold_expr_kind<F: Fold + ?Sized>(folder: &mut F, kind: ExprKind) -> ExprKind {
     match kind {
         ExprKind::Empty => ExprKind::Empty,
+        ExprKind::Quote(q) => ExprKind::Quote(q), // quoted expressions are left unmodified
+        ExprKind::Let(l) => ExprKind::Let(folder.fold_let(l)),
+        ExprKind::Match(m) => ExprKind::Match(folder.fold_match(m)),
         ExprKind::Assign(a) => ExprKind::Assign(folder.fold_assign(a)),
         ExprKind::Modify(m) => ExprKind::Modify(folder.fold_modify(m)),
         ExprKind::Binary(b) => ExprKind::Binary(folder.fold_binary(b)),
         ExprKind::Unary(u) => ExprKind::Unary(folder.fold_unary(u)),
+        ExprKind::Cast(c) => ExprKind::Cast(folder.fold_cast(c)),
         ExprKind::Member(m) => ExprKind::Member(folder.fold_member(m)),
         ExprKind::Index(i) => ExprKind::Index(folder.fold_index(i)),
         ExprKind::Structor(s) => ExprKind::Structor(folder.fold_structor(s)),
@@ -546,13 +589,12 @@ pub fn or_fold_expr_kind<F: Fold + ?Sized>(folder: &mut F, kind: ExprKind) -> Ex
         ExprKind::Block(b) => ExprKind::Block(folder.fold_block(b)),
         ExprKind::Group(g) => ExprKind::Group(folder.fold_group(g)),
         ExprKind::Tuple(t) => ExprKind::Tuple(folder.fold_tuple(t)),
-        ExprKind::Loop(l) => ExprKind::Loop(folder.fold_loop(l)),
         ExprKind::While(w) => ExprKind::While(folder.fold_while(w)),
         ExprKind::If(i) => ExprKind::If(folder.fold_if(i)),
         ExprKind::For(f) => ExprKind::For(folder.fold_for(f)),
         ExprKind::Break(b) => ExprKind::Break(folder.fold_break(b)),
         ExprKind::Return(r) => ExprKind::Return(folder.fold_return(r)),
-        ExprKind::Continue(c) => ExprKind::Continue(folder.fold_continue(c)),
+        ExprKind::Continue => ExprKind::Continue,
     }
 }
 pub fn or_fold_member_kind<F: Fold + ?Sized>(folder: &mut F, kind: MemberKind) -> MemberKind {

compiler/cl-ast/src/ast_visitor/visit.rs

@@ -23,6 +23,7 @@ pub trait Visit<'a>: Sized {
     fn visit_bool(&mut self, _b: &'a bool) {}
     fn visit_char(&mut self, _c: &'a char) {}
     fn visit_int(&mut self, _i: &'a u128) {}
+    fn visit_smuggled_float(&mut self, _f: &'a u64) {}
     fn visit_string(&mut self, _s: &'a str) {}
     fn visit_file(&mut self, f: &'a File) {
         let File { items } = f;
@@ -191,17 +192,6 @@ pub trait Visit<'a>: Sized {
         or_visit_stmt_kind(self, kind)
     }
     fn visit_semi(&mut self, _s: &'a Semi) {}
-    fn visit_let(&mut self, l: &'a Let) {
-        let Let { mutable, name, ty, init } = l;
-        self.visit_mutability(mutable);
-        self.visit_sym(name);
-        if let Some(ty) = ty {
-            self.visit_ty(ty);
-        }
-        if let Some(init) = init {
-            self.visit_expr(init)
-        }
-    }
     fn visit_expr(&mut self, e: &'a Expr) {
         let Expr { extents, kind } = e;
         self.visit_span(extents);
@@ -210,6 +200,55 @@ pub trait Visit<'a>: Sized {
     fn visit_expr_kind(&mut self, e: &'a ExprKind) {
         or_visit_expr_kind(self, e)
     }
+    fn visit_let(&mut self, l: &'a Let) {
+        let Let { mutable, name, ty, init } = l;
+        self.visit_mutability(mutable);
+        self.visit_pattern(name);
+        if let Some(ty) = ty {
+            self.visit_ty(ty);
+        }
+        if let Some(init) = init {
+            self.visit_expr(init)
+        }
+    }
+
+    fn visit_pattern(&mut self, p: &'a Pattern) {
+        match p {
+            Pattern::Path(path) => self.visit_path(path),
+            Pattern::Literal(literal) => self.visit_literal(literal),
+            Pattern::Ref(mutability, pattern) => {
+                self.visit_mutability(mutability);
+                self.visit_pattern(pattern);
+            }
+            Pattern::Tuple(patterns) => {
+                patterns.iter().for_each(|p| self.visit_pattern(p));
+            }
+            Pattern::Array(patterns) => {
+                patterns.iter().for_each(|p| self.visit_pattern(p));
+            }
+            Pattern::Struct(path, items) => {
+                self.visit_path(path);
+                items.iter().for_each(|(_name, bind)| {
+                    bind.as_ref().inspect(|bind| {
+                        self.visit_pattern(bind);
+                    });
+                });
+            }
+        }
+    }
+
+    fn visit_match(&mut self, m: &'a Match) {
+        let Match { scrutinee, arms } = m;
+        self.visit_expr(scrutinee);
+        arms.iter().for_each(|arm| self.visit_match_arm(arm));
+    }
+
+    fn visit_match_arm(&mut self, a: &'a MatchArm) {
+        let MatchArm(pat, expr) = a;
+        self.visit_pattern(pat);
+        self.visit_expr(expr);
+    }
+    
     fn visit_assign(&mut self, a: &'a Assign) {
         let Assign { parts } = a;
         let (head, tail) = parts.as_ref();
@@ -238,6 +277,11 @@ pub trait Visit<'a>: Sized {
         self.visit_expr_kind(tail);
     }
     fn visit_unary_kind(&mut self, _kind: &'a UnaryKind) {}
+    fn visit_cast(&mut self, cast: &'a Cast) {
+        let Cast { head, ty } = cast;
+        self.visit_expr_kind(head);
+        self.visit_ty(ty);
+    }
     fn visit_member(&mut self, m: &'a Member) {
         let Member { head, kind } = m;
         self.visit_expr_kind(head);
@@ -273,7 +317,7 @@ pub trait Visit<'a>: Sized {
         self.visit_expr_kind(repeat);
     }
     fn visit_addrof(&mut self, a: &'a AddrOf) {
-        let AddrOf { count: _, mutable, expr } = a;
+        let AddrOf { mutable, expr } = a;
         self.visit_mutability(mutable);
         self.visit_expr_kind(expr);
     }
@@ -289,10 +333,6 @@ pub trait Visit<'a>: Sized {
         let Tuple { exprs } = t;
         exprs.iter().for_each(|e| self.visit_expr(e))
     }
-    fn visit_loop(&mut self, l: &'a Loop) {
-        let Loop { body } = l;
-        self.visit_expr(body)
-    }
     fn visit_while(&mut self, w: &'a While) {
         let While { cond, pass, fail } = w;
         self.visit_expr(cond);
@@ -330,9 +370,7 @@ pub trait Visit<'a>: Sized {
             self.visit_expr(body)
         }
     }
-    fn visit_continue(&mut self, c: &'a Continue) {
-        let Continue = c;
-    }
+    fn visit_continue(&mut self) {}
 }
 
 pub fn or_visit_literal<'a, V: Visit<'a>>(visitor: &mut V, l: &'a Literal) {
@@ -340,6 +378,7 @@ pub fn or_visit_literal<'a, V: Visit<'a>>(visitor: &mut V, l: &'a Literal) {
         Literal::Bool(b) => visitor.visit_bool(b),
         Literal::Char(c) => visitor.visit_char(c),
         Literal::Int(i) => visitor.visit_int(i),
+        Literal::Float(f) => visitor.visit_smuggled_float(f),
         Literal::String(s) => visitor.visit_string(s),
     }
 }
@@ -443,7 +482,6 @@ pub fn or_visit_ty_kind<'a, V: Visit<'a>>(visitor: &mut V, kind: &'a TyKind) {
 pub fn or_visit_stmt_kind<'a, V: Visit<'a>>(visitor: &mut V, kind: &'a StmtKind) {
     match kind {
         StmtKind::Empty => {}
-        StmtKind::Local(l) => visitor.visit_let(l),
         StmtKind::Item(i) => visitor.visit_item(i),
         StmtKind::Expr(e) => visitor.visit_expr(e),
     }
@@ -452,10 +490,14 @@ pub fn or_visit_stmt_kind<'a, V: Visit<'a>>(visitor: &mut V, kind: &'a StmtKind)
 pub fn or_visit_expr_kind<'a, V: Visit<'a>>(visitor: &mut V, e: &'a ExprKind) {
     match e {
         ExprKind::Empty => {}
+        ExprKind::Quote(_q) => {} // Quoted expressions are left unvisited
+        ExprKind::Let(l) => visitor.visit_let(l),
+        ExprKind::Match(m) => visitor.visit_match(m),
         ExprKind::Assign(a) => visitor.visit_assign(a),
         ExprKind::Modify(m) => visitor.visit_modify(m),
         ExprKind::Binary(b) => visitor.visit_binary(b),
         ExprKind::Unary(u) => visitor.visit_unary(u),
+        ExprKind::Cast(c) => visitor.visit_cast(c),
         ExprKind::Member(m) => visitor.visit_member(m),
         ExprKind::Index(i) => visitor.visit_index(i),
         ExprKind::Structor(s) => visitor.visit_structor(s),
@@ -467,13 +509,12 @@ pub fn or_visit_expr_kind<'a, V: Visit<'a>>(visitor: &mut V, e: &'a ExprKind) {
         ExprKind::Block(b) => visitor.visit_block(b),
         ExprKind::Group(g) => visitor.visit_group(g),
         ExprKind::Tuple(t) => visitor.visit_tuple(t),
-        ExprKind::Loop(l) => visitor.visit_loop(l),
         ExprKind::While(w) => visitor.visit_while(w),
         ExprKind::If(i) => visitor.visit_if(i),
         ExprKind::For(f) => visitor.visit_for(f),
         ExprKind::Break(b) => visitor.visit_break(b),
         ExprKind::Return(r) => visitor.visit_return(r),
-        ExprKind::Continue(c) => visitor.visit_continue(c),
+        ExprKind::Continue => visitor.visit_continue(),
     }
 }
 pub fn or_visit_member_kind<'a, V: Visit<'a>>(visitor: &mut V, kind: &'a MemberKind) {

compiler/cl-ast/src/desugar/while_else.rs

@@ -26,8 +26,8 @@ fn desugar_while(extents: Span, kind: ExprKind) -> ExprKind {
             let break_expr = Expr { extents: fail_span, kind: ExprKind::Break(Break { body }) };
 
             let loop_body = If { cond, pass, fail: Else { body: Some(Box::new(break_expr)) } };
-            let loop_body = Expr { extents, kind: ExprKind::If(loop_body) };
-            ExprKind::Loop(Loop { body: Box::new(loop_body) })
+            let loop_body = ExprKind::If(loop_body);
+            ExprKind::Unary(Unary { kind: UnaryKind::Loop, tail: Box::new(loop_body) })
         }
         _ => kind,
     }

compiler/cl-ast/src/format.rs

@@ -21,7 +21,7 @@ pub struct Indent<'f, F: Write + ?Sized> {
     f: &'f mut F,
 }
 
-impl<'f, F: Write + ?Sized> Write for Indent<'f, F> {
+impl<F: Write + ?Sized> Write for Indent<'_, F> {
     fn write_str(&mut self, s: &str) -> std::fmt::Result {
         for s in s.split_inclusive('\n') {
             self.f.write_str(s)?;
@@ -45,14 +45,14 @@ impl<'f, F: Write + ?Sized> Delimit<'f, F> {
         Self { f, delim }
     }
 }
-impl<'f, F: Write + ?Sized> Drop for Delimit<'f, F> {
+impl<F: Write + ?Sized> Drop for Delimit<'_, F> {
     fn drop(&mut self) {
         let Self { f: Indent { f, .. }, delim } = self;
         let _ = f.write_str(delim.close);
     }
 }
 
-impl<'f, F: Write + ?Sized> Write for Delimit<'f, F> {
+impl<F: Write + ?Sized> Write for Delimit<'_, F> {
     fn write_str(&mut self, s: &str) -> std::fmt::Result {
         self.f.write_str(s)
     }

compiler/cl-ast/src/lib.rs

@@ -8,6 +8,7 @@
 //!   - [Assign], [Binary], and [Unary] expressions
 //!   - [ModifyKind], [BinaryKind], and [UnaryKind] operators
 //! - [Ty] and [TyKind]: Type qualifiers
+//! - [Pattern]: Pattern matching operators
 //! - [Path]: Path expressions
 #![warn(clippy::all)]
 #![feature(decl_macro)]

compiler/cl-interpret/examples/conlang-run.rs

@@ -0,0 +1,56 @@
+//! A bare-minimum harness to evaluate a Conlang program
+
+use std::{error::Error, path::PathBuf};
+
+use cl_ast::Expr;
+use cl_interpret::{convalue::ConValue, env::Environment};
+use cl_lexer::Lexer;
+use cl_parser::{inliner::ModuleInliner, Parser};
+
+fn main() -> Result<(), Box<dyn Error>> {
+    let mut args = std::env::args();
+
+    let prog = args.next().unwrap();
+    let Some(path) = args.next().map(PathBuf::from) else {
+        println!("Usage: {prog} `file.cl` [ args... ]");
+        return Ok(());
+    };
+
+    let parent = path.parent().unwrap_or("".as_ref());
+
+    let code = std::fs::read_to_string(&path)?;
+    let code = Parser::new(Lexer::new(&code)).parse()?;
+    let code = match ModuleInliner::new(parent).inline(code) {
+        Ok(code) => code,
+        Err((code, ioerrs, perrs)) => {
+            for (p, err) in ioerrs {
+                eprintln!("{}:{err}", p.display());
+            }
+            for (p, err) in perrs {
+                eprintln!("{}:{err}", p.display());
+            }
+            code
+        }
+    };
+
+    let mut env = Environment::new();
+    env.eval(&code)?;
+
+    let main = "main".into();
+    if env.get(main).is_ok() {
+        let args = args
+            .flat_map(|arg| {
+                Parser::new(Lexer::new(&arg))
+                    .parse::<Expr>()
+                    .map(|arg| env.eval(&arg))
+            })
+            .collect::<Result<Vec<_>, _>>()?;
+
+        match env.call(main, &args)? {
+            ConValue::Empty => {}
+            retval => println!("{retval}"),
+        }
+    }
+
+    Ok(())
+}

compiler/cl-interpret/src/builtin.rs

@@ -1,67 +1,192 @@
-//! Implementations of built-in functions
+#![allow(non_upper_case_globals)]
 
-use super::{
+use crate::{
     convalue::ConValue,
     env::Environment,
     error::{Error, IResult},
-    BuiltIn, Callable,
 };
-use cl_ast::Sym;
 use std::{
     io::{stdout, Write},
-    rc::Rc,
+    slice,
 };
 
-builtins! {
-    const MISC;
-    /// Unstable variadic format function
-    pub fn format<_, args> () -> IResult<ConValue> {
-        use std::fmt::Write;
-        let mut out = String::new();
-        for arg in args {
-            write!(out, "{arg}").ok();
-        }
-        Ok(ConValue::String(out.into()))
+/// A function built into the interpreter.
+#[derive(Clone, Copy)]
+pub struct Builtin {
+    /// An identifier to be used during registration
+    pub name: &'static str,
+    /// The signature, displayed when the builtin is printed
+    pub desc: &'static str,
+    /// The function to be run when called
+    pub func: &'static dyn Fn(&mut Environment, &[ConValue]) -> IResult<ConValue>,
+}
+
+impl Builtin {
+    /// Constructs a new Builtin
+    pub const fn new(
+        name: &'static str,
+        desc: &'static str,
+        func: &'static impl Fn(&mut Environment, &[ConValue]) -> IResult<ConValue>,
+    ) -> Builtin {
+        Builtin { name, desc, func }
     }
 
-    /// Unstable variadic print function
-    pub fn print<_, args> () -> IResult<ConValue> {
-        let mut out = stdout().lock();
-        for arg in args {
-            write!(out, "{arg}").ok();
-        }
-        Ok(ConValue::Empty)
-    }
-
-    /// Unstable variadic println function
-    pub fn println<_, args> () -> IResult<ConValue> {
-        let mut out = stdout().lock();
-        for arg in args {
-            write!(out, "{arg}").ok();
-        }
-        writeln!(out).ok();
-        Ok(ConValue::Empty)
-    }
-
-    /// Prints the [Debug](std::fmt::Debug) version of the input values
-    pub fn dbg<_, args> () -> IResult<ConValue> {
-        let mut out = stdout().lock();
-        for arg in args {
-            writeln!(out, "{arg:?}").ok();
-        }
-        Ok(args.into())
-    }
-
-    /// Dumps info from the environment
-    pub fn dump<env, _>() -> IResult<ConValue> {
-        println!("{}", *env);
-        Ok(ConValue::Empty)
+    pub const fn description(&self) -> &'static str {
+        self.desc
     }
 }
-builtins! {
-    const BINARY;
+
+impl std::fmt::Debug for Builtin {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("Builtin")
+            .field("description", &self.desc)
+            .finish_non_exhaustive()
+    }
+}
+
+impl super::Callable for Builtin {
+    fn call(&self, interpreter: &mut Environment, args: &[ConValue]) -> IResult<ConValue> {
+        (self.func)(interpreter, args)
+    }
+
+    fn name(&self) -> cl_ast::Sym {
+        self.name.into()
+    }
+}
+
+/// Turns a function definition into a [Builtin].
+///
+/// ```rust
+/// # use cl_interpret::{builtin2::builtin, convalue::ConValue};
+/// let my_builtin = builtin! {
+///     /// Use the `@env` suffix to bind the environment!
+///     /// (needed for recursive calls)
+///     fn my_builtin(ConValue::Bool(b), rest @ ..) @env {
+///         // This is all Rust code!
+///         eprintln!("my_builtin({b}, ..)");
+///         match rest {
+///             [] => Ok(ConValue::Empty),
+///             _ => my_builtin(env, rest), // Can be called as a normal function!
+///         }
+///     }
+/// };
+/// ```
+pub macro builtin(
+    $(#[$($meta:tt)*])*
+    fn $name:ident ($($arg:pat),*$(,)?) $(@$env:tt)? $body:block
+) {{
+    $(#[$($meta)*])*
+    fn $name(_env: &mut Environment, _args: &[ConValue]) -> IResult<ConValue> {
+        // Set up the builtin! environment
+        $(let $env = _env;)?
+        // Allow for single argument `fn foo(args @ ..)` pattern
+        #[allow(clippy::redundant_at_rest_pattern, irrefutable_let_patterns)]
+        let [$($arg),*] = _args else {
+            Err($crate::error::Error::TypeError)?
+        };
+        $body.map(Into::into)
+    }
+    Builtin {
+        name: stringify!($name),
+        desc: stringify![builtin fn $name($($arg),*)],
+        func: &$name,
+    }
+}}
+
+/// Constructs an array of [Builtin]s from pseudo-function definitions
+pub macro builtins($(
+    $(#[$($meta:tt)*])*
+    fn $name:ident ($($args:tt)*) $(@$env:tt)? $body:block
+)*) {
+    [$(builtin!($(#[$($meta)*])* fn $name ($($args)*) $(@$env)? $body)),*]
+}
+
+/// Creates an [Error::BuiltinDebug] using interpolation of runtime expressions.
+/// See [std::format].
+pub macro error_format ($($t:tt)*) {
+    $crate::error::Error::BuiltinDebug(format!($($t)*))
+}
+
+pub const Builtins: &[Builtin] = &builtins![
+    /// Unstable variadic format function
+    fn fmt(args @ ..) {
+        use std::fmt::Write;
+        let mut out = String::new();
+        if let Err(e) = args.iter().try_for_each(|arg| write!(out, "{arg}")) {
+            eprintln!("{e}");
+        }
+        Ok(out)
+    }
+
+    /// Prints the arguments in-order, with no separators
+    fn print(args @ ..) {
+        let mut out = stdout().lock();
+        args.iter().try_for_each(|arg| write!(out, "{arg}") ).ok();
+        Ok(())
+    }
+
+    /// Prints the arguments in-order, followed by a newline
+    fn println(args @ ..) {
+        let mut out = stdout().lock();
+        args.iter().try_for_each(|arg| write!(out, "{arg}") ).ok();
+        writeln!(out).ok();
+        Ok(())
+    }
+
+    /// Debug-prints the argument, returning a copy
+    fn dbg(arg) {
+        println!("{arg:?}");
+        Ok(arg.clone())
+    }
+
+    /// Debug-prints the argument
+    fn dbgp(args @ ..) {
+        let mut out = stdout().lock();
+        args.iter().try_for_each(|arg| writeln!(out, "{arg:#?}") ).ok();
+        Ok(())
+    }
+
+    /// Dumps the environment
+    fn dump() @env {
+        println!("{env}");
+        Ok(())
+    }
+
+    fn builtins() @env {
+        for builtin in env.builtins().values().flatten() {
+            println!("{builtin}");
+        }
+        Ok(())
+    }
+
+    /// Returns the length of the input list as a [ConValue::Int]
+    fn len(list) @env {
+        Ok(match list {
+            ConValue::Empty => 0,
+            ConValue::String(s) => s.chars().count() as _,
+            ConValue::Ref(r) => return len(env, slice::from_ref(r.as_ref())),
+            ConValue::Array(t) => t.len() as _,
+            ConValue::Tuple(t) => t.len() as _,
+            ConValue::RangeExc(start, end) => (end - start) as _,
+            ConValue::RangeInc(start, end) => (end - start + 1) as _,
+            _ => Err(Error::TypeError)?,
+        })
+    }
+
+    fn dump_symbols() {
+        println!("{}", cl_structures::intern::string_interner::StringInterner::global());
+        Ok(ConValue::Empty)
+    }
+
+    /// Returns a shark
+    fn shark() {
+        Ok('\u{1f988}')
+    }
+];
+
+pub const Math: &[Builtin] = &builtins![
     /// Multiplication `a * b`
-    pub fn mul(lhs, rhs) -> IResult<ConValue> {
+    fn mul(lhs, rhs) {
         Ok(match (lhs, rhs) {
             (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
             (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a * b),
@@ -70,7 +195,7 @@ builtins! {
     }
 
     /// Division `a / b`
-    pub fn div(lhs, rhs) -> IResult<ConValue> {
+    fn div(lhs, rhs) {
         Ok(match (lhs, rhs){
             (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
             (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a / b),
@@ -79,7 +204,7 @@ builtins! {
     }
 
     /// Remainder `a % b`
-    pub fn rem(lhs, rhs) -> IResult<ConValue> {
+    fn rem(lhs, rhs) {
         Ok(match (lhs, rhs) {
             (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
             (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a % b),
@@ -88,7 +213,7 @@ builtins! {
     }
 
     /// Addition `a + b`
-    pub fn add(lhs, rhs) -> IResult<ConValue> {
+    fn add(lhs, rhs) {
         Ok(match (lhs, rhs) {
             (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
             (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a + b),
@@ -98,7 +223,7 @@ builtins! {
     }
 
     /// Subtraction `a - b`
-    pub fn sub(lhs, rhs) -> IResult<ConValue> {
+    fn sub(lhs, rhs) {
         Ok(match (lhs, rhs) {
             (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
             (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a - b),
@@ -107,7 +232,7 @@ builtins! {
     }
 
     /// Shift Left `a << b`
-    pub fn shl(lhs, rhs) -> IResult<ConValue> {
+    fn shl(lhs, rhs) {
         Ok(match (lhs, rhs) {
             (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
             (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a << b),
@@ -116,7 +241,7 @@ builtins! {
     }
 
     /// Shift Right `a >> b`
-    pub fn shr(lhs, rhs) -> IResult<ConValue> {
+    fn shr(lhs, rhs) {
         Ok(match (lhs, rhs) {
             (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
             (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a >> b),
@@ -125,7 +250,7 @@ builtins! {
     }
 
     /// Bitwise And `a & b`
-    pub fn and(lhs, rhs) -> IResult<ConValue> {
+    fn and(lhs, rhs) {
         Ok(match (lhs, rhs) {
             (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
             (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a & b),
@@ -135,7 +260,7 @@ builtins! {
     }
 
     /// Bitwise Or `a | b`
-    pub fn or(lhs, rhs) -> IResult<ConValue> {
+    fn or(lhs, rhs) {
         Ok(match (lhs, rhs) {
             (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
             (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a | b),
@@ -145,7 +270,7 @@ builtins! {
     }
 
     /// Bitwise Exclusive Or `a ^ b`
-    pub fn xor(lhs, rhs) -> IResult<ConValue> {
+    fn xor(lhs, rhs) {
         Ok(match (lhs, rhs) {
             (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
             (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a ^ b),
@@ -154,67 +279,34 @@ builtins! {
         })
     }
 
-    /// Tests whether `a < b`
-    pub fn lt(lhs, rhs) -> IResult<ConValue> {
-        cmp!(lhs, rhs, false, <)
-    }
-
-    /// Tests whether `a <= b`
-    pub fn lt_eq(lhs, rhs) -> IResult<ConValue> {
-        cmp!(lhs, rhs, true, <=)
-    }
-
-    /// Tests whether `a == b`
-    pub fn eq(lhs, rhs) -> IResult<ConValue> {
-        cmp!(lhs, rhs, true, ==)
-    }
-
-    /// Tests whether `a != b`
-    pub fn neq(lhs, rhs) -> IResult<ConValue> {
-        cmp!(lhs, rhs, false, !=)
-    }
-
-    /// Tests whether `a <= b`
-    pub fn gt_eq(lhs, rhs) -> IResult<ConValue> {
-        cmp!(lhs, rhs, true, >=)
-    }
-
-    /// Tests whether `a < b`
-    pub fn gt(lhs, rhs) -> IResult<ConValue> {
-        cmp!(lhs, rhs, false, >)
-    }
-}
-builtins! {
-    const RANGE;
     /// Exclusive Range `a..b`
-    pub fn range_exc(lhs, rhs) -> IResult<ConValue> {
-        let (&ConValue::Int(lhs), &ConValue::Int(rhs)) = (lhs, rhs) else {
+    fn range_exc(from, to) {
+        let (&ConValue::Int(from), &ConValue::Int(to)) = (from, to) else {
             Err(Error::TypeError)?
         };
-        Ok(ConValue::RangeExc(lhs, rhs.saturating_sub(1)))
+        Ok(ConValue::RangeExc(from, to))
     }
 
     /// Inclusive Range `a..=b`
-    pub fn range_inc(lhs, rhs) -> IResult<ConValue> {
-        let (&ConValue::Int(lhs), &ConValue::Int(rhs)) = (lhs, rhs) else {
+    fn range_inc(from, to) {
+        let (&ConValue::Int(from), &ConValue::Int(to)) = (from, to) else {
             Err(Error::TypeError)?
         };
-        Ok(ConValue::RangeInc(lhs, rhs))
+        Ok(ConValue::RangeInc(from, to))
     }
-}
-builtins! {
-    const UNARY;
+
     /// Negates the ConValue
-    pub fn neg(tail) -> IResult<ConValue> {
+    fn neg(tail) {
         Ok(match tail {
             ConValue::Empty => ConValue::Empty,
             ConValue::Int(v) => ConValue::Int(v.wrapping_neg()),
+            ConValue::Float(v) => ConValue::Float(-v),
             _ => Err(Error::TypeError)?,
         })
     }
 
     /// Inverts the ConValue
-    pub fn not(tail) -> IResult<ConValue> {
+    fn not(tail) {
         Ok(match tail {
             ConValue::Empty => ConValue::Empty,
             ConValue::Int(v) => ConValue::Int(!v),
@@ -223,62 +315,23 @@ builtins! {
         })
     }
 
-    pub fn deref(tail) -> IResult<ConValue> {
+    /// Compares two values
+    fn cmp(head, tail) {
+        Ok(ConValue::Int(match (head, tail) {
+            (ConValue::Int(a), ConValue::Int(b)) => a.cmp(b) as _,
+            (ConValue::Bool(a), ConValue::Bool(b)) => a.cmp(b) as _,
+            (ConValue::Char(a), ConValue::Char(b)) => a.cmp(b) as _,
+            (ConValue::String(a), ConValue::String(b)) => a.cmp(b) as _,
+            _ => Err(error_format!("Incomparable values: {head}, {tail}"))?
+        }))
+    }
+
+    /// Does the opposite of `&`
+    fn deref(tail) {
+        use std::rc::Rc;
         Ok(match tail {
             ConValue::Ref(v) => Rc::as_ref(v).clone(),
             _ => tail.clone(),
         })
     }
-}
-
-/// Turns an argument slice into an array with the (inferred) correct number of elements
-pub fn to_args<const N: usize>(args: &[ConValue]) -> IResult<&[ConValue; N]> {
-    args.try_into()
-        .map_err(|_| Error::ArgNumber { want: N, got: args.len() })
-}
-
-/// Turns function definitions into ZSTs which implement [Callable] and [BuiltIn]
-macro builtins (
-    $(prefix = $prefix:literal)?
-    const $defaults:ident $( = [$($additional_builtins:expr),*$(,)?])?;
-    $(
-        $(#[$meta:meta])*$vis:vis fn $name:ident$(<$env:tt, $args:tt>)? ( $($($arg:tt),+$(,)?)? ) $(-> $rety:ty)?
-            $body:block
-    )*
-) {
-    /// Builtins to load when a new interpreter is created
-    pub const $defaults: &[&dyn BuiltIn] = &[$(&$name,)* $($additional_builtins)*];
-    $(
-        $(#[$meta])* #[allow(non_camel_case_types)] #[derive(Clone, Debug)]
-        /// ```rust,ignore
-        #[doc = stringify!(builtin! fn $name($($($arg),*)?) $(-> $rety)? $body)]
-        /// ```
-        $vis struct $name;
-        impl BuiltIn for $name {
-            fn description(&self) -> &str { concat!("builtin ", stringify!($name), stringify!(($($($arg),*)?) )) }
-        }
-        impl Callable for $name {
-            #[allow(unused)]
-            fn call(&self, env: &mut Environment, args: &[ConValue]) $(-> $rety)? {
-                // println!("{}", stringify!($name), );
-                $(let $env = env;
-                let $args = args;)?
-                $(let [$($arg),*] = to_args(args)?;)?
-                $body
-            }
-            fn name(&self) -> Sym { stringify!($name).into() }
-        }
-    )*
-}
-
-/// Templates comparison functions for [ConValue]
-macro cmp ($a:expr, $b:expr, $empty:literal, $op:tt) {
-    match ($a, $b) {
-        (ConValue::Empty, ConValue::Empty) => Ok(ConValue::Bool($empty)),
-        (ConValue::Int(a), ConValue::Int(b)) => Ok(ConValue::Bool(a $op b)),
-        (ConValue::Bool(a), ConValue::Bool(b)) => Ok(ConValue::Bool(a $op b)),
-        (ConValue::Char(a), ConValue::Char(b)) => Ok(ConValue::Bool(a $op b)),
-        (ConValue::String(a), ConValue::String(b)) => Ok(ConValue::Bool(&**a $op &**b)),
-        _ => Err(Error::TypeError)
-    }
-}
+];

compiler/cl-interpret/src/convalue.rs

@@ -0,0 +1,336 @@
+//! Values in the dynamically typed AST interpreter.
+//!
+//! The most permanent fix is a temporary one.
+use cl_ast::{format::FmtAdapter, ExprKind, Sym};
+
+use super::{
+    builtin::Builtin,
+    error::{Error, IResult},
+    function::Function, Callable, Environment,
+};
+use std::{collections::HashMap, ops::*, rc::Rc};
+
+type Integer = isize;
+
+/// A Conlang value stores data in the interpreter
+#[derive(Clone, Debug, Default)]
+pub enum ConValue {
+    /// The empty/unit `()` type
+    #[default]
+    Empty,
+    /// An integer
+    Int(Integer),
+    /// A floating point number
+    Float(f64),
+    /// A boolean
+    Bool(bool),
+    /// A unicode character
+    Char(char),
+    /// A string
+    String(Sym),
+    /// A reference
+    Ref(Rc<ConValue>),
+    /// An Array
+    Array(Box<[ConValue]>),
+    /// A tuple
+    Tuple(Box<[ConValue]>),
+    /// An exclusive range
+    RangeExc(Integer, Integer),
+    /// An inclusive range
+    RangeInc(Integer, Integer),
+    /// A value of a product type
+    Struct(Box<(Sym, HashMap<Sym, ConValue>)>),
+    /// An entire namespace
+    Module(Box<HashMap<Sym, Option<ConValue>>>),
+    /// A quoted expression
+    Quote(Box<ExprKind>),
+    /// A callable thing
+    Function(Rc<Function>),
+    /// A built-in function
+    Builtin(&'static Builtin),
+}
+
+impl ConValue {
+    /// Gets whether the current value is true or false
+    pub fn truthy(&self) -> IResult<bool> {
+        match self {
+            ConValue::Bool(v) => Ok(*v),
+            _ => Err(Error::TypeError)?,
+        }
+    }
+    pub fn range_exc(self, other: Self) -> IResult<Self> {
+        let (Self::Int(a), Self::Int(b)) = (self, other) else {
+            Err(Error::TypeError)?
+        };
+        Ok(Self::RangeExc(a, b))
+    }
+    pub fn range_inc(self, other: Self) -> IResult<Self> {
+        let (Self::Int(a), Self::Int(b)) = (self, other) else {
+            Err(Error::TypeError)?
+        };
+        Ok(Self::RangeInc(a, b))
+    }
+    pub fn index(&self, index: &Self) -> IResult<ConValue> {
+        let Self::Int(index) = index else {
+            Err(Error::TypeError)?
+        };
+        match self {
+            ConValue::String(string) => string
+                .chars()
+                .nth(*index as _)
+                .map(ConValue::Char)
+                .ok_or(Error::OobIndex(*index as usize, string.chars().count())),
+            ConValue::Array(arr) => arr
+                .get(*index as usize)
+                .cloned()
+                .ok_or(Error::OobIndex(*index as usize, arr.len())),
+            _ => Err(Error::TypeError),
+        }
+    }
+    cmp! {
+        lt: false, <;
+        lt_eq: true, <=;
+        eq: true, ==;
+        neq: false, !=;
+        gt_eq: true, >=;
+        gt: false, >;
+    }
+    assign! {
+        add_assign: +;
+        bitand_assign: &;
+        bitor_assign: |;
+        bitxor_assign: ^;
+        div_assign: /;
+        mul_assign: *;
+        rem_assign: %;
+        shl_assign: <<;
+        shr_assign: >>;
+        sub_assign: -;
+    }
+}
+
+impl Callable for ConValue {
+    fn name(&self) -> Sym {
+        match self {
+            ConValue::Function(func) => func.name(),
+            ConValue::Builtin(func) => func.name(),
+            _ => "".into(),
+        }
+    }
+    fn call(&self, interpreter: &mut Environment, args: &[ConValue]) -> IResult<ConValue> {
+        match self {
+            Self::Function(func) => func.call(interpreter, args),
+            Self::Builtin(func) => func.call(interpreter, args),
+            _ => Err(Error::NotCallable(self.clone())),
+        }
+    }
+}
+/// Templates comparison functions for [ConValue]
+macro cmp ($($fn:ident: $empty:literal, $op:tt);*$(;)?) {$(
+    /// TODO: Remove when functions are implemented:
+    ///       Desugar into function calls
+    pub fn $fn(&self, other: &Self) -> IResult<Self> {
+        match (self, other) {
+            (Self::Empty, Self::Empty) => Ok(Self::Bool($empty)),
+            (Self::Int(a), Self::Int(b)) => Ok(Self::Bool(a $op b)),
+            (Self::Float(a), Self::Float(b)) => Ok(Self::Bool(a $op b)),
+            (Self::Bool(a), Self::Bool(b)) => Ok(Self::Bool(a $op b)),
+            (Self::Char(a), Self::Char(b)) => Ok(Self::Bool(a $op b)),
+            (Self::String(a), Self::String(b)) => Ok(Self::Bool(&**a $op &**b)),
+            _ => Err(Error::TypeError)
+        }
+    }
+)*}
+macro assign($( $fn: ident: $op: tt );*$(;)?) {$(
+    pub fn $fn(&mut self, other: Self) -> IResult<()> {
+        *self = (std::mem::take(self) $op other)?;
+        Ok(())
+    }
+)*}
+/// Implements [From] for an enum with 1-tuple variants
+macro from ($($T:ty => $v:expr),*$(,)?) {
+    $(impl From<$T> for ConValue {
+        fn from(value: $T) -> Self { $v(value.into()) }
+    })*
+}
+impl From<&Sym> for ConValue {
+    fn from(value: &Sym) -> Self {
+        ConValue::String(*value)
+    }
+}
+from! {
+    Integer => ConValue::Int,
+    f64 => ConValue::Float,
+    bool => ConValue::Bool,
+    char => ConValue::Char,
+    Sym => ConValue::String,
+    &str => ConValue::String,
+    String => ConValue::String,
+    Rc<str> => ConValue::String,
+    ExprKind => ConValue::Quote,
+    Function => ConValue::Function,
+    Vec<ConValue> => ConValue::Tuple,
+    &'static Builtin => ConValue::Builtin,
+}
+impl From<()> for ConValue {
+    fn from(_: ()) -> Self {
+        Self::Empty
+    }
+}
+impl From<&[ConValue]> for ConValue {
+    fn from(value: &[ConValue]) -> Self {
+        match value.len() {
+            0 => Self::Empty,
+            1 => value[0].clone(),
+            _ => Self::Tuple(value.into()),
+        }
+    }
+}
+
+/// Implements binary [std::ops] traits for [ConValue]
+///
+/// TODO: Desugar operators into function calls
+macro ops($($trait:ty: $fn:ident = [$($match:tt)*])*) {
+    $(impl $trait for ConValue {
+        type Output = IResult<Self>;
+        /// TODO: Desugar operators into function calls
+        fn $fn(self, rhs: Self) -> Self::Output {Ok(match (self, rhs) {$($match)*})}
+    })*
+}
+ops! {
+    Add: add = [
+        (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
+        (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a.wrapping_add(b)),
+        (ConValue::Float(a), ConValue::Float(b)) => ConValue::Float(a + b),
+        (ConValue::String(a), ConValue::String(b)) => (a.to_string() + &*b).into(),
+        (ConValue::String(s), ConValue::Char(c)) => { let mut s = s.to_string(); s.push(c); s.into() }
+        (ConValue::Char(a), ConValue::Char(b)) => {
+            ConValue::String([a, b].into_iter().collect::<String>().into())
+        }
+        _ => Err(Error::TypeError)?
+        ]
+    BitAnd: bitand = [
+        (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
+        (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a & b),
+        (ConValue::Bool(a), ConValue::Bool(b)) => ConValue::Bool(a & b),
+        _ => Err(Error::TypeError)?
+    ]
+    BitOr: bitor = [
+        (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
+        (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a | b),
+        (ConValue::Bool(a), ConValue::Bool(b)) => ConValue::Bool(a | b),
+        _ => Err(Error::TypeError)?
+    ]
+    BitXor: bitxor = [
+        (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
+        (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a ^ b),
+        (ConValue::Bool(a), ConValue::Bool(b)) => ConValue::Bool(a ^ b),
+        _ => Err(Error::TypeError)?
+    ]
+    Div: div = [
+        (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
+        (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a.checked_div(b).unwrap_or_else(|| {
+            eprintln!("Warning: Divide by zero in {a} / {b}"); a
+        })),
+        (ConValue::Float(a), ConValue::Float(b)) => ConValue::Float(a / b),
+        _ => Err(Error::TypeError)?
+    ]
+    Mul: mul = [
+        (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
+        (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a.wrapping_mul(b)),
+        (ConValue::Float(a), ConValue::Float(b)) => ConValue::Float(a * b),
+        _ => Err(Error::TypeError)?
+    ]
+    Rem: rem = [
+        (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
+        (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a.checked_rem(b).unwrap_or_else(|| {
+            println!("Warning: Divide by zero in {a} % {b}"); a
+        })),
+        (ConValue::Float(a), ConValue::Float(b)) => ConValue::Float(a % b),
+        _ => Err(Error::TypeError)?
+    ]
+    Shl: shl = [
+        (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
+        (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a.wrapping_shl(b as _)),
+        _ => Err(Error::TypeError)?
+    ]
+    Shr: shr = [
+        (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
+        (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a.wrapping_shr(b as _)),
+        _ => Err(Error::TypeError)?
+    ]
+    Sub: sub = [
+        (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
+        (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a.wrapping_sub(b)),
+        (ConValue::Float(a), ConValue::Float(b)) => ConValue::Float(a - b),
+        _ => Err(Error::TypeError)?
+    ]
+}
+impl std::fmt::Display for ConValue {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            ConValue::Empty => "Empty".fmt(f),
+            ConValue::Int(v) => v.fmt(f),
+            ConValue::Float(v) => v.fmt(f),
+            ConValue::Bool(v) => v.fmt(f),
+            ConValue::Char(v) => v.fmt(f),
+            ConValue::String(v) => v.fmt(f),
+            ConValue::Ref(v) => write!(f, "&{v}"),
+            ConValue::Array(array) => {
+                '['.fmt(f)?;
+                for (idx, element) in array.iter().enumerate() {
+                    if idx > 0 {
+                        ", ".fmt(f)?
+                    }
+                    element.fmt(f)?
+                }
+                ']'.fmt(f)
+            }
+            ConValue::RangeExc(a, b) => write!(f, "{a}..{}", b + 1),
+            ConValue::RangeInc(a, b) => write!(f, "{a}..={b}"),
+            ConValue::Tuple(tuple) => {
+                '('.fmt(f)?;
+                for (idx, element) in tuple.iter().enumerate() {
+                    if idx > 0 {
+                        ", ".fmt(f)?
+                    }
+                    element.fmt(f)?
+                }
+                ')'.fmt(f)
+            }
+            ConValue::Struct(parts) => {
+                let (name, map) = parts.as_ref();
+                use std::fmt::Write;
+                if !name.is_empty() {
+                    write!(f, "{name}: ")?;
+                }
+                let mut f = f.delimit_with("{", "\n}");
+                for (k, v) in map.iter() {
+                    write!(f, "\n{k}: {v},")?;
+                }
+                Ok(())
+            }
+            ConValue::Module(module) => {
+                use std::fmt::Write;
+                let mut f = f.delimit_with("{", "\n}");
+                for (k, v) in module.iter() {
+                    write!(f, "\n{k}: ")?;
+                    match v {
+                        Some(v) => write!(f, "{v},"),
+                        None => write!(f, "_,"),
+                    }?
+                }
+                Ok(())
+            }
+            ConValue::Quote(q) => {
+                write!(f, "`{q}`")
+            }
+            ConValue::Function(func) => {
+                write!(f, "{}", func.decl())
+            }
+            ConValue::Builtin(func) => {
+                write!(f, "{}", func.description())
+            }
+        }
+    }
+}

compiler/cl-interpret/src/env.rs

@@ -0,0 +1,236 @@
+//! Lexical and non-lexical scoping for variables
+
+use crate::builtin::Builtin;
+
+use super::{
+    builtin::{Builtins, Math},
+    convalue::ConValue,
+    error::{Error, IResult},
+    function::Function,
+    Callable, Interpret,
+};
+use cl_ast::{Function as FnDecl, Sym};
+use std::{
+    collections::HashMap,
+    fmt::Display,
+    ops::{Deref, DerefMut},
+    rc::Rc,
+};
+
+type StackFrame = HashMap<Sym, Option<ConValue>>;
+
+/// Implements a nested lexical scope
+#[derive(Clone, Debug)]
+pub struct Environment {
+    builtin: StackFrame,
+    global: Vec<(StackFrame, &'static str)>,
+    frames: Vec<(StackFrame, &'static str)>,
+}
+
+impl Display for Environment {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        for (frame, name) in self
+            .global
+            .iter()
+            .rev()
+            .take(2)
+            .rev()
+            .chain(self.frames.iter())
+        {
+            writeln!(f, "--- {name} ---")?;
+            for (var, val) in frame {
+                write!(f, "{var}: ")?;
+                match val {
+                    Some(value) => writeln!(f, "\t{value}"),
+                    None => writeln!(f, "<undefined>"),
+                }?
+            }
+        }
+        Ok(())
+    }
+}
+impl Default for Environment {
+    fn default() -> Self {
+        Self {
+            builtin: to_hashmap(Builtins.iter().chain(Math.iter())),
+            global: vec![(HashMap::new(), "globals")],
+            frames: vec![],
+        }
+    }
+}
+
+fn to_hashmap(from: impl IntoIterator<Item = &'static Builtin>) -> HashMap<Sym, Option<ConValue>> {
+    from.into_iter()
+        .map(|v| (v.name(), Some(v.into())))
+        .collect()
+}
+
+impl Environment {
+    pub fn new() -> Self {
+        Self::default()
+    }
+    /// Creates an [Environment] with no [builtins](super::builtin)
+    pub fn no_builtins() -> Self {
+        Self {
+            builtin: HashMap::new(),
+            global: vec![(Default::default(), "globals")],
+            frames: vec![],
+        }
+    }
+
+    pub fn builtins(&self) -> &StackFrame {
+        &self.builtin
+    }
+
+    pub fn add_builtin(&mut self, builtin: &'static Builtin) -> &mut Self {
+        self.builtin.insert(builtin.name(), Some(builtin.into()));
+        self
+    }
+
+    pub fn add_builtins(&mut self, builtins: &'static [Builtin]) {
+        for builtin in builtins {
+            self.add_builtin(builtin);
+        }
+    }
+
+    pub fn push_frame(&mut self, name: &'static str, frame: StackFrame) {
+        self.frames.push((frame, name));
+    }
+
+    pub fn pop_frame(&mut self) -> Option<(StackFrame, &'static str)> {
+        self.frames.pop()
+    }
+
+    pub fn eval(&mut self, node: &impl Interpret) -> IResult<ConValue> {
+        node.interpret(self)
+    }
+
+    /// Calls a function inside the interpreter's scope,
+    /// and returns the result
+    pub fn call(&mut self, name: Sym, args: &[ConValue]) -> IResult<ConValue> {
+        // FIXME: Clone to satisfy the borrow checker
+        let function = self.get(name)?.clone();
+        function.call(self, args)
+    }
+    /// Enters a nested scope, returning a [`Frame`] stack-guard.
+    ///
+    /// [`Frame`] implements Deref/DerefMut for [`Environment`].
+    pub fn frame(&mut self, name: &'static str) -> Frame {
+        Frame::new(self, name)
+    }
+    /// Resolves a variable mutably.
+    ///
+    /// Returns a mutable reference to the variable's record, if it exists.
+    pub fn get_mut(&mut self, id: Sym) -> IResult<&mut Option<ConValue>> {
+        for (frame, _) in self.frames.iter_mut().rev() {
+            if let Some(var) = frame.get_mut(&id) {
+                return Ok(var);
+            }
+        }
+        for (frame, _) in self.global.iter_mut().rev() {
+            if let Some(var) = frame.get_mut(&id) {
+                return Ok(var);
+            }
+        }
+        self.builtin.get_mut(&id).ok_or(Error::NotDefined(id))
+    }
+    /// Resolves a variable immutably.
+    ///
+    /// Returns a reference to the variable's contents, if it is defined and initialized.
+    pub fn get(&self, id: Sym) -> IResult<ConValue> {
+        for (frame, _) in self.frames.iter().rev() {
+            match frame.get(&id) {
+                Some(Some(var)) => return Ok(var.clone()),
+                Some(None) => return Err(Error::NotInitialized(id)),
+                _ => (),
+            }
+        }
+        for (frame, _) in self.global.iter().rev() {
+            match frame.get(&id) {
+                Some(Some(var)) => return Ok(var.clone()),
+                Some(None) => return Err(Error::NotInitialized(id)),
+                _ => (),
+            }
+        }
+        self.builtin
+            .get(&id)
+            .cloned()
+            .flatten()
+            .ok_or(Error::NotDefined(id))
+    }
+
+    pub(crate) fn get_local(&self, id: Sym) -> IResult<ConValue> {
+        for (frame, _) in self.frames.iter().rev() {
+            match frame.get(&id) {
+                Some(Some(var)) => return Ok(var.clone()),
+                Some(None) => return Err(Error::NotInitialized(id)),
+                _ => (),
+            }
+        }
+        Err(Error::NotInitialized(id))
+    }
+
+    /// Inserts a new [ConValue] into this [Environment]
+    pub fn insert(&mut self, id: Sym, value: Option<ConValue>) {
+        if let Some((frame, _)) = self.frames.last_mut() {
+            frame.insert(id, value);
+        } else if let Some((frame, _)) = self.global.last_mut() {
+            frame.insert(id, value);
+        }
+    }
+    /// A convenience function for registering a [FnDecl] as a [Function]
+    pub fn insert_fn(&mut self, decl: &FnDecl) {
+        let FnDecl { name, .. } = decl;
+        let (name, function) = (name, Rc::new(Function::new(decl)));
+        if let Some((frame, _)) = self.frames.last_mut() {
+            frame.insert(*name, Some(ConValue::Function(function.clone())));
+        } else if let Some((frame, _)) = self.global.last_mut() {
+            frame.insert(*name, Some(ConValue::Function(function.clone())));
+        }
+        // Tell the function to lift its upvars now, after it's been declared
+        function.lift_upvars(self);
+    }
+}
+
+/// Functions which aid in the implementation of [`Frame`]
+impl Environment {
+    /// Enters a scope, creating a new namespace for variables
+    fn enter(&mut self, name: &'static str) -> &mut Self {
+        self.frames.push((Default::default(), name));
+        self
+    }
+
+    /// Exits the scope, destroying all local variables and
+    /// returning the outer scope, if there is one
+    fn exit(&mut self) -> &mut Self {
+        self.frames.pop();
+        self
+    }
+}
+
+/// Represents a stack frame
+#[derive(Debug)]
+pub struct Frame<'scope> {
+    scope: &'scope mut Environment,
+}
+impl<'scope> Frame<'scope> {
+    fn new(scope: &'scope mut Environment, name: &'static str) -> Self {
+        Self { scope: scope.enter(name) }
+    }
+}
+impl Deref for Frame<'_> {
+    type Target = Environment;
+    fn deref(&self) -> &Self::Target {
+        self.scope
+    }
+}
+impl DerefMut for Frame<'_> {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        self.scope
+    }
+}
+impl Drop for Frame<'_> {
+    fn drop(&mut self) {
+        self.scope.exit();
+    }
+}

compiler/cl-interpret/src/error.rs

@@ -0,0 +1,97 @@
+//! The [Error] type represents any error thrown by the [Environment](super::Environment)
+
+use cl_ast::{Pattern, Sym};
+
+use super::convalue::ConValue;
+
+pub type IResult<T> = Result<T, Error>;
+
+/// Represents any error thrown by the [Environment](super::Environment)
+#[derive(Clone, Debug)]
+pub enum Error {
+    /// Propagate a Return value
+    Return(ConValue),
+    /// Propagate a Break value
+    Break(ConValue),
+    /// Break propagated across function bounds
+    BadBreak(ConValue),
+    /// Continue to the next iteration of a loop
+    Continue,
+    /// Underflowed the stack
+    StackUnderflow,
+    /// Exited the last scope
+    ScopeExit,
+    /// Type incompatibility
+    // TODO: store the type information in this error
+    TypeError,
+    /// In clause of For loop didn't yield a Range
+    NotIterable,
+    /// A value could not be indexed
+    NotIndexable,
+    /// An array index went out of bounds
+    OobIndex(usize, usize),
+    /// An expression is not assignable
+    NotAssignable,
+    /// A name was not defined in scope before being used
+    NotDefined(Sym),
+    /// A name was defined but not initialized
+    NotInitialized(Sym),
+    /// A value was called, but is not callable
+    NotCallable(ConValue),
+    /// A function was called with the wrong number of arguments
+    ArgNumber { want: usize, got: usize },
+    /// A pattern failed to match
+    PatFailed(Box<Pattern>),
+    /// Fell through a non-exhaustive match
+    MatchNonexhaustive,
+    /// Error produced by a Builtin
+    BuiltinDebug(String),
+}
+
+impl std::error::Error for Error {}
+impl std::fmt::Display for Error {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Error::Return(value) => write!(f, "return {value}"),
+            Error::Break(value) => write!(f, "break {value}"),
+            Error::BadBreak(value) => write!(f, "rogue break: {value}"),
+            Error::Continue => "continue".fmt(f),
+            Error::StackUnderflow => "Stack underflow".fmt(f),
+            Error::ScopeExit => "Exited the last scope. This is a logic bug.".fmt(f),
+            Error::TypeError => "Incompatible types".fmt(f),
+            Error::NotIterable => "`in` clause of `for` loop did not yield an iterable".fmt(f),
+            Error::NotIndexable => {
+                write!(f, "expression cannot be indexed")
+            }
+            Error::OobIndex(idx, len) => {
+                write!(f, "Index out of bounds: index was {idx}. but len is {len}")
+            }
+            Error::NotAssignable => {
+                write!(f, "expression is not assignable")
+            }
+            Error::NotDefined(value) => {
+                write!(f, "{value} not bound. Did you mean `let {value};`?")
+            }
+            Error::NotInitialized(value) => {
+                write!(f, "{value} bound, but not initialized")
+            }
+            Error::NotCallable(value) => {
+                write!(f, "{value} is not callable.")
+            }
+            Error::ArgNumber { want, got } => {
+                write!(
+                    f,
+                    "Expected {want} argument{}, got {got}",
+                    if *want == 1 { "" } else { "s" }
+                )
+            }
+            Error::PatFailed(pattern) => {
+                write!(f, "Failed to match pattern {pattern}")
+            }
+            Error::MatchNonexhaustive => {
+                write!(f, "Fell through a non-exhaustive match expression!")
+            }
+            Error::BuiltinDebug(s) => write!(f, "DEBUG: {s}"),
+        }
+    }
+}

compiler/cl-interpret/src/function.rs

@@ -0,0 +1,80 @@
+//! Represents a block of code which lives inside the Interpreter
+
+use collect_upvars::collect_upvars;
+
+use super::{Callable, ConValue, Environment, Error, IResult, Interpret};
+use cl_ast::{Function as FnDecl, Param, Sym};
+use std::{
+    cell::{Ref, RefCell},
+    collections::HashMap,
+    rc::Rc,
+};
+
+pub mod collect_upvars;
+
+type Upvars = HashMap<Sym, Option<ConValue>>;
+
+/// Represents a block of code which persists inside the Interpreter
+#[derive(Clone, Debug)]
+pub struct Function {
+    /// Stores the contents of the function declaration
+    decl: Rc<FnDecl>,
+    /// Stores data from the enclosing scopes
+    upvars: RefCell<Upvars>,
+}
+
+impl Function {
+    pub fn new(decl: &FnDecl) -> Self {
+        // let upvars = collect_upvars(decl, env);
+        Self { decl: decl.clone().into(), upvars: Default::default() }
+    }
+    pub fn decl(&self) -> &FnDecl {
+        &self.decl
+    }
+    pub fn upvars(&self) -> Ref<Upvars> {
+        self.upvars.borrow()
+    }
+    pub fn lift_upvars(&self, env: &Environment) {
+        let upvars = collect_upvars(&self.decl, env);
+        if let Ok(mut self_upvars) = self.upvars.try_borrow_mut() {
+            *self_upvars = upvars;
+        }
+    }
+}
+
+impl Callable for Function {
+    fn name(&self) -> Sym {
+        let FnDecl { name, .. } = *self.decl;
+        name
+    }
+    fn call(&self, env: &mut Environment, args: &[ConValue]) -> IResult<ConValue> {
+        let FnDecl { name, bind, body, sign: _ } = &*self.decl;
+
+        // Check arg mapping
+        if args.len() != bind.len() {
+            return Err(Error::ArgNumber { want: bind.len(), got: args.len() });
+        }
+        let Some(body) = body else {
+            return Err(Error::NotDefined(*name));
+        };
+
+        let upvars = self.upvars.take();
+        env.push_frame("upvars", upvars);
+
+        // TODO: completely refactor data storage
+        let mut frame = env.frame("fn args");
+        for (Param { mutability: _, name }, value) in bind.iter().zip(args) {
+            frame.insert(*name, Some(value.clone()));
+        }
+        let res = body.interpret(&mut frame);
+        drop(frame);
+        if let Some((upvars, _)) = env.pop_frame() {
+            self.upvars.replace(upvars);
+        }
+        match res {
+            Err(Error::Return(value)) => Ok(value),
+            Err(Error::Break(value)) => Err(Error::BadBreak(value)),
+            result => result,
+        }
+    }
+}

compiler/cl-interpret/src/function/collect_upvars.rs

@@ -0,0 +1,134 @@
+//! Collects the "Upvars" of a function at the point of its creation, allowing variable capture
+use crate::{convalue::ConValue, env::Environment};
+use cl_ast::{ast_visitor::visit::*, Function, Let, Param, Path, PathPart, Pattern, Sym};
+use std::collections::{HashMap, HashSet};
+
+pub fn collect_upvars(f: &Function, env: &Environment) -> super::Upvars {
+    CollectUpvars::new(env).get_upvars(f)
+}
+
+#[derive(Clone, Debug)]
+pub struct CollectUpvars<'env> {
+    env: &'env Environment,
+    upvars: HashMap<Sym, Option<ConValue>>,
+    blacklist: HashSet<Sym>,
+}
+
+impl<'env> CollectUpvars<'env> {
+    pub fn new(env: &'env Environment) -> Self {
+        Self { upvars: HashMap::new(), blacklist: HashSet::new(), env }
+    }
+    pub fn get_upvars(mut self, f: &cl_ast::Function) -> HashMap<Sym, Option<ConValue>> {
+        self.visit_function(f);
+        self.upvars
+    }
+
+    pub fn add_upvar(&mut self, name: &Sym) {
+        let Self { env, upvars, blacklist } = self;
+        if blacklist.contains(name) || upvars.contains_key(name) {
+            return;
+        }
+        if let Ok(upvar) = env.get_local(*name) {
+            upvars.insert(*name, Some(upvar));
+        }
+    }
+
+    pub fn bind_name(&mut self, name: &Sym) {
+        self.blacklist.insert(*name);
+    }
+}
+
+impl<'a> Visit<'a> for CollectUpvars<'_> {
+    fn visit_block(&mut self, b: &'a cl_ast::Block) {
+        let blacklist = self.blacklist.clone();
+
+        // visit the block
+        let cl_ast::Block { stmts } = b;
+        stmts.iter().for_each(|s| self.visit_stmt(s));
+
+        // restore the blacklist
+        self.blacklist = blacklist;
+    }
+
+    fn visit_let(&mut self, l: &'a cl_ast::Let) {
+        let Let { mutable, name, ty, init } = l;
+        self.visit_mutability(mutable);
+        if let Some(ty) = ty {
+            self.visit_ty(ty);
+        }
+        // visit the initializer, which may use the bound name
+        if let Some(init) = init {
+            self.visit_expr(init)
+        }
+        // a bound name can never be an upvar
+        self.visit_pattern(name);
+    }
+
+    fn visit_function(&mut self, f: &'a cl_ast::Function) {
+        let Function { name: _, sign: _, bind, body } = f;
+        // parameters can never be upvars
+        for Param { mutability: _, name } in bind {
+            self.bind_name(name);
+        }
+        if let Some(body) = body {
+            self.visit_block(body);
+        }
+    }
+
+    fn visit_for(&mut self, f: &'a cl_ast::For) {
+        let cl_ast::For { bind, cond, pass, fail } = f;
+        self.visit_expr(cond);
+        self.visit_else(fail);
+        self.bind_name(bind); // TODO: is bind only bound in the pass block?
+        self.visit_block(pass);
+    }
+
+    fn visit_path(&mut self, p: &'a cl_ast::Path) {
+        // TODO: path resolution in environments
+        let Path { absolute: false, parts } = p else {
+            return;
+        };
+        let [PathPart::Ident(name)] = parts.as_slice() else {
+            return;
+        };
+        self.add_upvar(name);
+    }
+
+    fn visit_fielder(&mut self, f: &'a cl_ast::Fielder) {
+        let cl_ast::Fielder { name, init } = f;
+        if let Some(init) = init {
+            self.visit_expr(init);
+        } else {
+            self.add_upvar(name); // fielder without init grabs from env
+        }
+    }
+
+    fn visit_pattern(&mut self, p: &'a cl_ast::Pattern) {
+        match p {
+            Pattern::Path(path) => {
+                if let [PathPart::Ident(name)] = path.parts.as_slice() {
+                    self.bind_name(name)
+                }
+            }
+            Pattern::Literal(literal) => self.visit_literal(literal),
+            Pattern::Ref(mutability, pattern) => {
+                self.visit_mutability(mutability);
+                self.visit_pattern(pattern);
+            }
+            Pattern::Tuple(patterns) => {
+                patterns.iter().for_each(|p| self.visit_pattern(p));
+            }
+            Pattern::Array(patterns) => {
+                patterns.iter().for_each(|p| self.visit_pattern(p));
+            }
+            Pattern::Struct(path, items) => {
+                self.visit_path(path);
+                items.iter().for_each(|(_name, bind)| {
+                    bind.as_ref().inspect(|bind| {
+                        self.visit_pattern(bind);
+                    });
+                });
+            }
+        }
+    }
+}

compiler/cl-interpret/src/interpret.rs

@@ -9,6 +9,7 @@ use std::{borrow::Borrow, rc::Rc};
 
 use super::*;
 use cl_ast::*;
+use cl_structures::intern::interned::Interned;
 /// A work-in-progress tree walk interpreter for Conlang
 pub trait Interpret {
     /// Interprets this thing in the given [`Environment`].
@@ -36,7 +37,7 @@ impl Interpret for Item {
             ItemKind::Struct(item) => item.interpret(env),
             ItemKind::Enum(item) => item.interpret(env),
             ItemKind::Impl(item) => item.interpret(env),
-            ItemKind::Use(_) => todo!("namespaces and imports in the interpreter"),
+            ItemKind::Use(item) => item.interpret(env),
         }
     }
 }
@@ -67,11 +68,21 @@ impl Interpret for Static {
 impl Interpret for Module {
     fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
         let Self { name, kind } = self;
-        // TODO: Enter this module's namespace
-        match kind {
+        env.push_frame(Interned::to_ref(name), Default::default());
+        let out = match kind {
             ModuleKind::Inline(file) => file.interpret(env),
-            ModuleKind::Outline => Err(Error::Outlined(*name)),
-        }
+            ModuleKind::Outline => {
+                eprintln!("Module {name} specified, but not imported.");
+                Ok(ConValue::Empty)
+            }
+        };
+
+        let (frame, _) = env
+            .pop_frame()
+            .expect("Environment frames must be balanced");
+        env.insert(*name, Some(ConValue::Module(frame.into())));
+
+        out
     }
 }
 impl Interpret for Function {
@@ -100,12 +111,78 @@ impl Interpret for Impl {
         body.interpret(env)
     }
 }
+
+impl Interpret for Use {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        let Self { absolute: _, tree } = self;
+        tree.interpret(env)
+    }
+}
+
+impl Interpret for UseTree {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        type Bindings = HashMap<Sym, ConValue>;
+        use std::collections::HashMap;
+
+        fn get_bindings(
+            tree: &UseTree,
+            env: &mut Environment,
+            bindings: &mut Bindings,
+        ) -> IResult<()> {
+            match tree {
+                UseTree::Tree(use_trees) => {
+                    for tree in use_trees {
+                        get_bindings(tree, env, bindings)?;
+                    }
+                }
+                UseTree::Path(PathPart::Ident(name), tree) => {
+                    let Ok(ConValue::Module(m)) = env.get(*name) else {
+                        Err(Error::TypeError)?
+                    };
+                    env.push_frame(Interned::to_ref(name), *m);
+                    let out = get_bindings(tree, env, bindings);
+                    env.pop_frame();
+                    return out;
+                }
+                UseTree::Alias(name, alias) => {
+                    bindings.insert(*alias, env.get(*name)?);
+                }
+                UseTree::Name(name) => {
+                    bindings.insert(*name, env.get(*name)?);
+                }
+                UseTree::Glob => {
+                    if let Some((frame, name)) = env.pop_frame() {
+                        for (k, v) in &frame {
+                            if let Some(v) = v {
+                                bindings.insert(*k, v.clone());
+                            }
+                        }
+                        env.push_frame(name, frame);
+                    }
+                }
+                other => {
+                    eprintln!("ERROR: Cannot use {other}");
+                }
+            }
+            Ok(())
+        }
+
+        let mut bindings = Bindings::new();
+        get_bindings(self, env, &mut bindings)?;
+
+        for (name, value) in bindings {
+            env.insert(name, Some(value));
+        }
+
+        Ok(ConValue::Empty)
+    }
+}
+
 impl Interpret for Stmt {
     fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
         let Self { extents: _, kind, semi } = self;
         let out = match kind {
             StmtKind::Empty => ConValue::Empty,
-            StmtKind::Local(stmt) => stmt.interpret(env)?,
             StmtKind::Item(stmt) => stmt.interpret(env)?,
             StmtKind::Expr(stmt) => stmt.interpret(env)?,
         };
@@ -115,14 +192,7 @@ impl Interpret for Stmt {
         })
     }
 }
-impl Interpret for Let {
-    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
-        let Let { mutable: _, name, ty: _, init } = self;
-        let init = init.as_ref().map(|i| i.interpret(env)).transpose()?;
-        env.insert(*name, init);
-        Ok(ConValue::Empty)
-    }
-}
+
 impl Interpret for Expr {
     #[inline]
     fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
@@ -130,14 +200,19 @@ impl Interpret for Expr {
         kind.interpret(env)
     }
 }
+
 impl Interpret for ExprKind {
     fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
         match self {
             ExprKind::Empty => Ok(ConValue::Empty),
+            ExprKind::Quote(q) => q.interpret(env),
+            ExprKind::Let(v) => v.interpret(env),
+            ExprKind::Match(v) => v.interpret(env),
             ExprKind::Assign(v) => v.interpret(env),
             ExprKind::Modify(v) => v.interpret(env),
             ExprKind::Binary(v) => v.interpret(env),
             ExprKind::Unary(v) => v.interpret(env),
+            ExprKind::Cast(v) => v.interpret(env),
             ExprKind::Member(v) => v.interpret(env),
             ExprKind::Index(v) => v.interpret(env),
             ExprKind::Structor(v) => v.interpret(env),
@@ -149,36 +224,306 @@ impl Interpret for ExprKind {
             ExprKind::Block(v) => v.interpret(env),
             ExprKind::Group(v) => v.interpret(env),
             ExprKind::Tuple(v) => v.interpret(env),
-            ExprKind::Loop(v) => v.interpret(env),
             ExprKind::While(v) => v.interpret(env),
             ExprKind::If(v) => v.interpret(env),
             ExprKind::For(v) => v.interpret(env),
             ExprKind::Break(v) => v.interpret(env),
             ExprKind::Return(v) => v.interpret(env),
-            ExprKind::Continue(v) => v.interpret(env),
+            ExprKind::Continue => Err(Error::Continue),
         }
     }
 }
 
-fn evaluate_place_expr<'e>(
-    env: &'e mut Environment,
-    expr: &ExprKind,
-) -> IResult<(&'e mut Option<ConValue>, Sym)> {
-    match expr {
-        ExprKind::Path(Path { parts, .. }) if parts.len() == 1 => {
-            match parts.last().expect("parts should not be empty") {
-                PathPart::SuperKw => Err(Error::NotAssignable),
-                PathPart::SelfKw => todo!("Assignment to `self`"),
-                PathPart::SelfTy => todo!("What does it mean to assign to capital-S Self?"),
-                PathPart::Ident(s) => env.get_mut(*s).map(|v| (v, *s)),
+impl Interpret for Quote {
+    fn interpret(&self, _env: &mut Environment) -> IResult<ConValue> {
+        // TODO: squoosh down into a ConValue?
+        Ok(ConValue::Quote(self.quote.clone()))
+    }
+}
+
+impl Interpret for Let {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        let Let { mutable: _, name, ty: _, init } = self;
+        match init.as_ref().map(|i| i.interpret(env)).transpose()? {
+            Some(value) => {
+                for (path, value) in assignment::pattern_substitution(name, value)? {
+                    match path.parts.as_slice() {
+                        [PathPart::Ident(name)] => env.insert(*name, Some(value)),
+                        _ => eprintln!("Bad assignment: {path} = {value}"),
+                    }
+                }
+            }
+            None => {
+                for path in assignment::pattern_variables(name) {
+                    match path.parts.as_slice() {
+                        [PathPart::Ident(name)] => env.insert(*name, None),
+                        _ => eprintln!("Bad assignment: {path}"),
+                    }
+                }
             }
         }
-        ExprKind::Index(_) => todo!("Assignment to an index operation"),
-        ExprKind::Path(_) => todo!("Path expression resolution (IMPORTANT)"),
-        ExprKind::Empty | ExprKind::Group(_) | ExprKind::Tuple(_) => {
-            todo!("Pattern Destructuring?")
+        Ok(ConValue::Empty)
+    }
+}
+
+impl Interpret for Match {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        let Self { scrutinee, arms } = self;
+        let scrutinee = scrutinee.interpret(env)?;
+        'arm: for MatchArm(pat, expr) in arms {
+            if let Ok(substitution) = assignment::pattern_substitution(pat, scrutinee.clone()) {
+                let mut env = env.frame("match");
+                for (path, value) in substitution {
+                    let [PathPart::Ident(name)] = path.parts.as_slice() else {
+                        continue 'arm;
+                    };
+                    env.insert(*name, Some(value));
+                }
+                return expr.interpret(&mut env);
+            }
+        }
+        Err(Error::MatchNonexhaustive)
+    }
+}
+
+mod assignment {
+    /// Pattern matching engine for assignment
+    use super::*;
+    use std::collections::HashMap;
+    type Namespace = HashMap<Sym, Option<ConValue>>;
+
+    /// Gets the path variables in the given Pattern
+    pub fn pattern_variables(pat: &Pattern) -> Vec<&Path> {
+        fn patvars<'p>(set: &mut Vec<&'p Path>, pat: &'p Pattern) {
+            match pat {
+                Pattern::Path(path) if path.is_sinkhole() => {}
+                Pattern::Path(path) => set.push(path),
+                Pattern::Literal(_) => {}
+                Pattern::Ref(_, pattern) => patvars(set, pattern),
+                Pattern::Tuple(patterns) | Pattern::Array(patterns) => {
+                    patterns.iter().for_each(|pat| patvars(set, pat))
+                }
+                Pattern::Struct(_path, items) => {
+                    items.iter().for_each(|(name, pat)| match pat {
+                        Some(pat) => patvars(set, pat),
+                        None => set.push(name),
+                    });
+                }
+            }
+        }
+        let mut set = Vec::new();
+        patvars(&mut set, pat);
+        set
+    }
+
+    /// Appends a substitution to the provided table
+    pub fn append_sub<'pat>(
+        env: &mut HashMap<&'pat Path, ConValue>,
+        pat: &'pat Pattern,
+        value: ConValue,
+    ) -> IResult<()> {
+        match pat {
+            Pattern::Path(path) if path.is_sinkhole() => Ok(()),
+            Pattern::Path(path) => {
+                env.insert(path, value);
+                Ok(())
+            }
+
+            Pattern::Literal(literal) => match (literal, value) {
+                (Literal::Bool(a), ConValue::Bool(b)) => *a == b,
+                (Literal::Char(a), ConValue::Char(b)) => *a == b,
+                (Literal::Int(a), ConValue::Int(b)) => *a as isize == b,
+                (Literal::Float(a), ConValue::Float(b)) => f64::from_bits(*a) == b,
+                (Literal::String(a), ConValue::String(b)) => *a == *b,
+                _ => false,
+            }
+            .then_some(())
+            .ok_or(Error::NotAssignable),
+
+            Pattern::Ref(_, pattern) => match value {
+                ConValue::Ref(value) => append_sub(env, pattern, Rc::unwrap_or_clone(value)),
+                _ => Err(Error::NotAssignable),
+            },
+
+            Pattern::Tuple(patterns) => match value {
+                ConValue::Tuple(values) => {
+                    if patterns.len() != values.len() {
+                        return Err(Error::OobIndex(patterns.len(), values.len()));
+                    };
+                    for (pat, value) in patterns.iter().zip(Vec::from(values).into_iter()) {
+                        append_sub(env, pat, value)?;
+                    }
+                    Ok(())
+                }
+                _ => Err(Error::NotAssignable),
+            },
+
+            Pattern::Array(patterns) => match value {
+                ConValue::Array(values) => {
+                    if patterns.len() != values.len() {
+                        return Err(Error::OobIndex(patterns.len(), values.len()));
+                    };
+                    for (pat, value) in patterns.iter().zip(Vec::from(values).into_iter()) {
+                        append_sub(env, pat, value)?;
+                    }
+                    Ok(())
+                }
+                _ => Err(Error::NotAssignable),
+            },
+
+            Pattern::Struct(_path, patterns) => {
+                let ConValue::Struct(parts) = value else {
+                    return Err(Error::TypeError);
+                };
+                let (_, mut values) = *parts;
+                if values.len() != patterns.len() {
+                    return Err(Error::TypeError);
+                }
+                for (name, pat) in patterns {
+                    let [.., PathPart::Ident(index)] = name.parts.as_slice() else {
+                        Err(Error::TypeError)?
+                    };
+                    let value = values.remove(index).ok_or(Error::TypeError)?;
+                    match pat {
+                        Some(pat) => append_sub(env, pat, value)?,
+                        None => {
+                            env.insert(name, value);
+                        }
+                    }
+                }
+
+                Ok(())
+            }
+        }
+    }
+
+    /// Constructs a substitution from a pattern and a value
+    pub fn pattern_substitution(
+        pat: &Pattern,
+        value: ConValue,
+    ) -> IResult<HashMap<&Path, ConValue>> {
+        let mut substitution = HashMap::new();
+        append_sub(&mut substitution, pat, value)?;
+        Ok(substitution)
+    }
+
+    pub(super) fn pat_assign(env: &mut Environment, pat: &Pattern, value: ConValue) -> IResult<()> {
+        let mut substitution = HashMap::new();
+        append_sub(&mut substitution, pat, value)
+            .map_err(|_| Error::PatFailed(pat.clone().into()))?;
+        for (path, value) in substitution {
+            assign_path(env, path, value)?;
+        }
+        Ok(())
+    }
+
+    pub(super) fn assign(env: &mut Environment, pat: &ExprKind, value: ConValue) -> IResult<()> {
+        if let Ok(pat) = Pattern::try_from(pat.clone()) {
+            return pat_assign(env, &pat, value);
+        }
+        match pat {
+            ExprKind::Member(member) => *addrof_member(env, member)? = value,
+            ExprKind::Index(index) => *addrof_index(env, index)? = value,
+            _ => Err(Error::NotAssignable)?,
+        }
+        Ok(())
+    }
+
+    fn assign_path(env: &mut Environment, path: &Path, value: ConValue) -> IResult<()> {
+        let Ok(addr) = addrof_path(env, &path.parts) else {
+            eprintln!("Cannot assign {value} to path {path}");
+            return Err(Error::NotAssignable);
+        };
+        *addr = Some(value);
+        Ok(())
+    }
+
+    pub(super) fn addrof<'e>(
+        env: &'e mut Environment,
+        pat: &ExprKind,
+    ) -> IResult<&'e mut ConValue> {
+        match pat {
+            ExprKind::Path(path) => addrof_path(env, &path.parts)?
+                .as_mut()
+                .ok_or(Error::NotInitialized("".into())),
+            ExprKind::Member(member) => addrof_member(env, member),
+            ExprKind::Index(index) => addrof_index(env, index),
+            ExprKind::Group(Group { expr }) => addrof(env, expr),
+            ExprKind::AddrOf(AddrOf { mutable: Mutability::Mut, expr }) => addrof(env, expr),
+            _ => Err(Error::TypeError),
+        }
+    }
+
+    pub fn addrof_path<'e>(
+        env: &'e mut Environment,
+        path: &[PathPart],
+    ) -> IResult<&'e mut Option<ConValue>> {
+        match path {
+            [PathPart::Ident(name)] => env.get_mut(*name),
+            [PathPart::Ident(name), rest @ ..] => match env.get_mut(*name)? {
+                Some(ConValue::Module(env)) => addrof_path_within_namespace(env, rest),
+                _ => Err(Error::NotIndexable),
+            },
+            _ => Err(Error::NotAssignable),
+        }
+    }
+
+    fn addrof_member<'e>(env: &'e mut Environment, member: &Member) -> IResult<&'e mut ConValue> {
+        let Member { head, kind } = member;
+        let ExprKind::Path(path) = head.as_ref() else {
+            return Err(Error::TypeError);
+        };
+        let slot = addrof_path(env, &path.parts)?
+            .as_mut()
+            .ok_or(Error::NotAssignable)?;
+        Ok(match (slot, kind) {
+            (ConValue::Struct(s), MemberKind::Struct(id)) => {
+                s.1.get_mut(id).ok_or(Error::NotDefined(*id))?
+            }
+            (ConValue::Tuple(t), MemberKind::Tuple(Literal::Int(id))) => t
+                .get_mut(*id as usize)
+                .ok_or_else(|| Error::NotDefined(id.to_string().into()))?,
+            _ => Err(Error::TypeError)?,
+        })
+    }
+
+    fn addrof_index<'e>(env: &'e mut Environment, index: &Index) -> IResult<&'e mut ConValue> {
+        let Index { head, indices } = index;
+        let indices = indices
+            .iter()
+            .map(|index| index.interpret(env))
+            .collect::<IResult<Vec<_>>>()?;
+        let mut head = addrof(env, head)?;
+        for index in indices {
+            head = match (head, index) {
+                (ConValue::Array(a), ConValue::Int(i)) => {
+                    let a_len = a.len();
+                    a.get_mut(i as usize)
+                        .ok_or(Error::OobIndex(i as usize, a_len))?
+                }
+                _ => Err(Error::NotIndexable)?,
+            }
+        }
+        Ok(head)
+    }
+
+    pub fn addrof_path_within_namespace<'e>(
+        env: &'e mut Namespace,
+        path: &[PathPart],
+    ) -> IResult<&'e mut Option<ConValue>> {
+        match path {
+            [] => Err(Error::NotAssignable),
+            [PathPart::Ident(name)] => env.get_mut(name).ok_or(Error::NotDefined(*name)),
+            [PathPart::Ident(name), rest @ ..] => {
+                match env.get_mut(name).ok_or(Error::NotDefined(*name))? {
+                    Some(ConValue::Module(env)) => addrof_path_within_namespace(env, rest),
+                    _ => Err(Error::NotIndexable),
+                }
+            }
+            [PathPart::SelfKw, rest @ ..] => addrof_path_within_namespace(env, rest),
+            [PathPart::SelfTy, ..] => todo!("calc_address for `Self`"),
+            [PathPart::SuperKw, ..] => todo!("calc_address for `super`"),
         }
-        _ => Err(Error::NotAssignable),
     }
 }
 
@@ -188,17 +533,7 @@ impl Interpret for Assign {
         let (head, tail) = parts.borrow();
         let init = tail.interpret(env)?;
         // Resolve the head pattern
-        let target = evaluate_place_expr(env, head)?;
-        use std::mem::discriminant as variant;
-        // runtime typecheck
-        match target.0 {
-            Some(value) if variant(value) == variant(&init) => {
-                *value = init;
-            }
-            value @ None => *value = Some(init),
-            _ => Err(Error::TypeError)?,
-        }
-        Ok(ConValue::Empty)
+        assignment::assign(env, head, init).map(|_| ConValue::Empty)
     }
 }
 impl Interpret for Modify {
@@ -208,10 +543,7 @@ impl Interpret for Modify {
         // Get the initializer and the tail
         let init = tail.interpret(env)?;
         // Resolve the head pattern
-        let target = evaluate_place_expr(env, head)?;
-        let (Some(target), _) = target else {
-            return Err(Error::NotInitialized(target.1));
-        };
+        let target = assignment::addrof(env, head)?;
 
         match op {
             ModifyKind::Add => target.add_assign(init),
@@ -321,12 +653,28 @@ impl Interpret for Binary {
 impl Interpret for Unary {
     fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
         let Unary { kind, tail } = self;
-        let operand = tail.interpret(env)?;
         match kind {
-            UnaryKind::Deref => env.call("deref".into(), &[operand]),
-            UnaryKind::Neg => env.call("neg".into(), &[operand]),
-            UnaryKind::Not => env.call("not".into(), &[operand]),
+            UnaryKind::Loop => loop {
+                match tail.interpret(env) {
+                    Err(Error::Break(value)) => return Ok(value),
+                    Err(Error::Continue) => continue,
+                    e => e?,
+                };
+            },
+            UnaryKind::Deref => {
+                let operand = tail.interpret(env)?;
+                env.call("deref".into(), &[operand])
+            }
+            UnaryKind::Neg => {
+                let operand = tail.interpret(env)?;
+                env.call("neg".into(), &[operand])
+            }
+            UnaryKind::Not => {
+                let operand = tail.interpret(env)?;
+                env.call("not".into(), &[operand])
+            }
             UnaryKind::At => {
+                let operand = tail.interpret(env)?;
                 println!("{operand}");
                 Ok(operand)
             }
@@ -334,6 +682,53 @@ impl Interpret for Unary {
         }
     }
 }
+
+fn cast(value: ConValue, ty: Sym) -> IResult<ConValue> {
+    let value = match value {
+        ConValue::Empty => 0,
+        ConValue::Int(i) => i as _,
+        ConValue::Bool(b) => b as _,
+        ConValue::Char(c) => c as _,
+        ConValue::Ref(v) => return cast((*v).clone(), ty),
+        // TODO: This, better
+        ConValue::Float(_) if ty.starts_with('f') => return Ok(value),
+        ConValue::Float(f) => f as _,
+        _ => Err(Error::TypeError)?,
+    };
+    Ok(match &*ty {
+        "u8" => ConValue::Int(value as u8 as _),
+        "i8" => ConValue::Int(value as i8 as _),
+        "u16" => ConValue::Int(value as u16 as _),
+        "i16" => ConValue::Int(value as i16 as _),
+        "u32" => ConValue::Int(value as u32 as _),
+        "i32" => ConValue::Int(value as i32 as _),
+        "u64" => ConValue::Int(value),
+        "i64" => ConValue::Int(value),
+        "f32" => ConValue::Float(value as f32 as _),
+        "f64" => ConValue::Float(value as f64 as _),
+        "char" => ConValue::Char(char::from_u32(value as _).unwrap_or('\u{fffd}')),
+        "bool" => ConValue::Bool(value < 0),
+        _ => Err(Error::NotDefined(ty))?,
+    })
+}
+
+impl Interpret for Cast {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        let Cast { head, ty } = self;
+        let value = head.interpret(env)?;
+        if TyKind::Empty == ty.kind {
+            return Ok(ConValue::Empty);
+        };
+        let TyKind::Path(Path { absolute: false, parts }) = &ty.kind else {
+            Err(Error::TypeError)?
+        };
+        match parts.as_slice() {
+            [PathPart::Ident(ty)] => cast(value, *ty),
+            _ => Err(Error::TypeError),
+        }
+    }
+}
+
 impl Interpret for Member {
     fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
         let Member { head, kind } = self;
@@ -343,6 +738,20 @@ impl Interpret for Member {
                 .get(*id as usize)
                 .cloned()
                 .ok_or(Error::OobIndex(*id as usize, v.len())),
+            (ConValue::Struct(parts), MemberKind::Struct(name)) => {
+                parts.1.get(name).cloned().ok_or(Error::NotDefined(*name))
+            }
+            (ConValue::Struct(parts), MemberKind::Call(name, args)) => {
+                let mut values = vec![];
+                for arg in &args.exprs {
+                    values.push(arg.interpret(env)?);
+                }
+                (parts.1)
+                    .get(name)
+                    .cloned()
+                    .ok_or(Error::NotDefined(*name))?
+                    .call(env, &values)
+            }
             (head, MemberKind::Call(name, args)) => {
                 let mut values = vec![head];
                 for arg in &args.exprs {
@@ -366,22 +775,37 @@ impl Interpret for Index {
 }
 impl Interpret for Structor {
     fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
-        todo!("struct construction in {env}")
+        let Self { to: Path { absolute: _, parts }, init } = self;
+        use std::collections::HashMap;
+
+        let name = match parts.last() {
+            Some(PathPart::Ident(name)) => *name,
+            Some(PathPart::SelfKw) => "self".into(),
+            Some(PathPart::SelfTy) => "Self".into(),
+            Some(PathPart::SuperKw) => "super".into(),
+            None => "".into(),
+        };
+
+        let mut map = HashMap::new();
+        for Fielder { name, init } in init {
+            let value = match init {
+                Some(init) => init.interpret(env)?,
+                None => env.get(*name)?,
+            };
+            map.insert(*name, value);
+        }
+        Ok(ConValue::Struct(Box::new((name, map))))
     }
 }
+
 impl Interpret for Path {
     fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
         let Self { absolute: _, parts } = self;
 
-        if parts.len() == 1 {
-            match parts.last().expect("parts should not be empty") {
-                PathPart::SuperKw | PathPart::SelfKw => todo!("Path navigation"),
-                PathPart::SelfTy => todo!("Path navigation to Self"),
-                PathPart::Ident(name) => env.get(*name),
-            }
-        } else {
-            todo!("Path navigation!")
-        }
+        assignment::addrof_path(env, parts)
+            .cloned()
+            .transpose()
+            .ok_or_else(|| Error::NotInitialized(format!("{self}").into()))?
     }
 }
 impl Interpret for Literal {
@@ -390,7 +814,7 @@ impl Interpret for Literal {
             Literal::String(value) => ConValue::from(value.as_str()),
             Literal::Char(value) => ConValue::Char(*value),
             Literal::Bool(value) => ConValue::Bool(*value),
-            // Literal::Float(value) => todo!("Float values in interpreter: {value:?}"),
+            Literal::Float(value) => ConValue::Float(f64::from_bits(*value)),
             Literal::Int(value) => ConValue::Int(*value as _),
         })
     }
@@ -418,13 +842,9 @@ impl Interpret for ArrayRep {
 }
 impl Interpret for AddrOf {
     fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
-        let Self { count: _, mutable: _, expr } = self;
+        let Self { mutable: _, expr } = self;
         match expr.as_ref() {
             ExprKind::Index(_) => todo!("AddrOf array index"),
-            // ExprKind::Path(Path { absolute: false, parts }) => match parts.as_slice() {
-            //     [PathPart::Ident(id)] => env.get_ref(id),
-            //     _ => todo!("Path traversal in addrof"),
-            // },
             ExprKind::Path(_) => todo!("Path traversal in addrof"),
             _ => Ok(ConValue::Ref(Rc::new(expr.interpret(env)?))),
         }
@@ -461,18 +881,6 @@ impl Interpret for Tuple {
         ))
     }
 }
-impl Interpret for Loop {
-    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
-        let Self { body } = self;
-        loop {
-            match body.interpret(env) {
-                Err(Error::Break(value)) => return Ok(value),
-                Err(Error::Continue) => continue,
-                e => e?,
-            };
-        }
-    }
-}
 impl Interpret for While {
     fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
         let Self { cond, pass, fail } = self;
@@ -502,16 +910,19 @@ impl Interpret for If {
 impl Interpret for For {
     fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
         let Self { bind: name, cond, pass, fail } = self;
+        let cond = cond.interpret(env)?;
         // TODO: A better iterator model
-        let mut bounds = match cond.interpret(env)? {
-            ConValue::RangeExc(a, b) => a..=b,
-            ConValue::RangeInc(a, b) => a..=b,
+        let mut bounds: Box<dyn Iterator<Item = ConValue>> = match &cond {
+            &ConValue::RangeExc(a, b) => Box::new((a..b).map(ConValue::Int)),
+            &ConValue::RangeInc(a, b) => Box::new((a..=b).map(ConValue::Int)),
+            ConValue::Array(a) => Box::new(a.iter().cloned()),
+            ConValue::String(s) => Box::new(s.chars().map(ConValue::Char)),
             _ => Err(Error::TypeError)?,
         };
         loop {
             let mut env = env.frame("loop variable");
             if let Some(loop_var) = bounds.next() {
-                env.insert(*name, Some(loop_var.into()));
+                env.insert(*name, Some(loop_var));
                 match pass.interpret(&mut env) {
                     Err(Error::Break(value)) => return Ok(value),
                     Err(Error::Continue) => continue,
@@ -532,11 +943,6 @@ impl Interpret for Else {
         }
     }
 }
-impl Interpret for Continue {
-    fn interpret(&self, _env: &mut Environment) -> IResult<ConValue> {
-        Err(Error::Continue)
-    }
-}
 impl Interpret for Return {
     fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
         let Self { body } = self;

compiler/cl-interpret/src/lib.rs

@@ -17,616 +17,17 @@ pub trait Callable: std::fmt::Debug {
     fn name(&self) -> Sym;
 }
 
-/// [BuiltIn]s are [Callable]s with bespoke definitions
-pub trait BuiltIn: std::fmt::Debug + Callable {
-    fn description(&self) -> &str;
-}
-
-pub mod convalue {
-    //! Values in the dynamically typed AST interpreter.
-    //!
-    //! The most permanent fix is a temporary one.
-    use cl_ast::Sym;
-
-    use super::{
-        error::{Error, IResult},
-        function::Function,
-        BuiltIn, Callable, Environment,
-    };
-    use std::{ops::*, rc::Rc};
-
-    type Integer = isize;
-
-    /// A Conlang value stores data in the interpreter
-    #[derive(Clone, Debug, Default)]
-    pub enum ConValue {
-        /// The empty/unit `()` type
-        #[default]
-        Empty,
-        /// An integer
-        Int(Integer),
-        /// A boolean
-        Bool(bool),
-        /// A unicode character
-        Char(char),
-        /// A string
-        String(Sym),
-        /// A reference
-        Ref(Rc<ConValue>),
-        /// An Array
-        Array(Rc<[ConValue]>),
-        /// A tuple
-        Tuple(Rc<[ConValue]>),
-        /// An exclusive range
-        RangeExc(Integer, Integer),
-        /// An inclusive range
-        RangeInc(Integer, Integer),
-        /// A callable thing
-        Function(Function),
-        /// A built-in function
-        BuiltIn(&'static dyn BuiltIn),
-    }
-    impl ConValue {
-        /// Gets whether the current value is true or false
-        pub fn truthy(&self) -> IResult<bool> {
-            match self {
-                ConValue::Bool(v) => Ok(*v),
-                _ => Err(Error::TypeError)?,
-            }
-        }
-        pub fn range_exc(self, other: Self) -> IResult<Self> {
-            let (Self::Int(a), Self::Int(b)) = (self, other) else {
-                Err(Error::TypeError)?
-            };
-            Ok(Self::RangeExc(a, b.saturating_sub(1)))
-        }
-        pub fn range_inc(self, other: Self) -> IResult<Self> {
-            let (Self::Int(a), Self::Int(b)) = (self, other) else {
-                Err(Error::TypeError)?
-            };
-            Ok(Self::RangeInc(a, b))
-        }
-        pub fn index(&self, index: &Self) -> IResult<ConValue> {
-            let Self::Int(index) = index else {
-                Err(Error::TypeError)?
-            };
-            let Self::Array(arr) = self else {
-                Err(Error::TypeError)?
-            };
-            arr.get(*index as usize)
-                .cloned()
-                .ok_or(Error::OobIndex(*index as usize, arr.len()))
-        }
-        cmp! {
-            lt: false, <;
-            lt_eq: true, <=;
-            eq: true, ==;
-            neq: false, !=;
-            gt_eq: true, >=;
-            gt: false, >;
-        }
-        assign! {
-            add_assign: +;
-            bitand_assign: &;
-            bitor_assign: |;
-            bitxor_assign: ^;
-            div_assign: /;
-            mul_assign: *;
-            rem_assign: %;
-            shl_assign: <<;
-            shr_assign: >>;
-            sub_assign: -;
-        }
-    }
-
-    impl Callable for ConValue {
-        fn name(&self) -> Sym {
-            match self {
-                ConValue::Function(func) => func.name(),
-                ConValue::BuiltIn(func) => func.name(),
-                _ => "".into(),
-            }
-        }
-        fn call(&self, interpreter: &mut Environment, args: &[ConValue]) -> IResult<ConValue> {
-            match self {
-                Self::Function(func) => func.call(interpreter, args),
-                Self::BuiltIn(func) => func.call(interpreter, args),
-                _ => Err(Error::NotCallable(self.clone())),
-            }
-        }
-    }
-    /// Templates comparison functions for [ConValue]
-    macro cmp ($($fn:ident: $empty:literal, $op:tt);*$(;)?) {$(
-        /// TODO: Remove when functions are implemented:
-        ///       Desugar into function calls
-        pub fn $fn(&self, other: &Self) -> IResult<Self> {
-            match (self, other) {
-                (Self::Empty, Self::Empty) => Ok(Self::Bool($empty)),
-                (Self::Int(a), Self::Int(b)) => Ok(Self::Bool(a $op b)),
-                (Self::Bool(a), Self::Bool(b)) => Ok(Self::Bool(a $op b)),
-                (Self::Char(a), Self::Char(b)) => Ok(Self::Bool(a $op b)),
-                (Self::String(a), Self::String(b)) => Ok(Self::Bool(&**a $op &**b)),
-                _ => Err(Error::TypeError)
-            }
-        }
-    )*}
-    macro assign($( $fn: ident: $op: tt );*$(;)?) {$(
-        pub fn $fn(&mut self, other: Self) -> IResult<()> {
-            *self = (std::mem::take(self) $op other)?;
-            Ok(())
-        }
-    )*}
-    /// Implements [From] for an enum with 1-tuple variants
-    macro from ($($T:ty => $v:expr),*$(,)?) {
-        $(impl From<$T> for ConValue {
-            fn from(value: $T) -> Self { $v(value.into()) }
-        })*
-    }
-    impl From<&Sym> for ConValue {
-        fn from(value: &Sym) -> Self {
-            ConValue::String(*value)
-        }
-    }
-    from! {
-        Integer => ConValue::Int,
-        bool => ConValue::Bool,
-        char => ConValue::Char,
-        Sym => ConValue::String,
-        &str => ConValue::String,
-        String => ConValue::String,
-        Rc<str> => ConValue::String,
-        Function => ConValue::Function,
-        Vec<ConValue> => ConValue::Tuple,
-        &'static dyn BuiltIn => ConValue::BuiltIn,
-    }
-    impl From<()> for ConValue {
-        fn from(_: ()) -> Self {
-            Self::Empty
-        }
-    }
-    impl From<&[ConValue]> for ConValue {
-        fn from(value: &[ConValue]) -> Self {
-            match value.len() {
-                0 => Self::Empty,
-                1 => value[0].clone(),
-                _ => Self::Tuple(value.into()),
-            }
-        }
-    }
-
-    /// Implements binary [std::ops] traits for [ConValue]
-    ///
-    /// TODO: Desugar operators into function calls
-    macro ops($($trait:ty: $fn:ident = [$($match:tt)*])*) {
-        $(impl $trait for ConValue {
-            type Output = IResult<Self>;
-            /// TODO: Desugar operators into function calls
-            fn $fn(self, rhs: Self) -> Self::Output {Ok(match (self, rhs) {$($match)*})}
-        })*
-    }
-    ops! {
-        Add: add = [
-            (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
-            (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a.wrapping_add(b)),
-            (ConValue::String(a), ConValue::String(b)) => (a.to_string() + &b.to_string()).into(),
-            (ConValue::String(s), ConValue::Char(c)) => { let mut s = s.to_string(); s.push(c); s.into() }
-            (ConValue::Char(a), ConValue::Char(b)) => {
-                ConValue::String([a, b].into_iter().collect::<String>().into())
-            }
-            _ => Err(Error::TypeError)?
-            ]
-        BitAnd: bitand = [
-            (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
-            (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a & b),
-            (ConValue::Bool(a), ConValue::Bool(b)) => ConValue::Bool(a & b),
-            _ => Err(Error::TypeError)?
-        ]
-        BitOr: bitor = [
-            (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
-            (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a | b),
-            (ConValue::Bool(a), ConValue::Bool(b)) => ConValue::Bool(a | b),
-            _ => Err(Error::TypeError)?
-        ]
-        BitXor: bitxor = [
-            (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
-            (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a ^ b),
-            (ConValue::Bool(a), ConValue::Bool(b)) => ConValue::Bool(a ^ b),
-            _ => Err(Error::TypeError)?
-        ]
-        Div: div = [
-            (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
-            (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a.checked_div(b).unwrap_or_else(|| {
-                eprintln!("Warning: Divide by zero in {a} / {b}"); a
-            })),
-            _ => Err(Error::TypeError)?
-        ]
-        Mul: mul = [
-            (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
-            (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a.wrapping_mul(b)),
-            _ => Err(Error::TypeError)?
-        ]
-        Rem: rem = [
-            (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
-            (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a.checked_rem(b).unwrap_or_else(|| {
-                eprintln!("Warning: Divide by zero in {a} % {b}"); a
-            })),
-            _ => Err(Error::TypeError)?
-        ]
-        Shl: shl = [
-            (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
-            (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a.wrapping_shl(b as _)),
-            _ => Err(Error::TypeError)?
-        ]
-        Shr: shr = [
-            (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
-            (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a.wrapping_shr(b as _)),
-            _ => Err(Error::TypeError)?
-        ]
-        Sub: sub = [
-            (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
-            (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a.wrapping_sub(b)),
-            _ => Err(Error::TypeError)?
-        ]
-    }
-    impl std::fmt::Display for ConValue {
-        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-            match self {
-                ConValue::Empty => "Empty".fmt(f),
-                ConValue::Int(v) => v.fmt(f),
-                ConValue::Bool(v) => v.fmt(f),
-                ConValue::Char(v) => v.fmt(f),
-                ConValue::String(v) => v.fmt(f),
-                ConValue::Ref(v) => write!(f, "&{v}"),
-                ConValue::Array(array) => {
-                    '['.fmt(f)?;
-                    for (idx, element) in array.iter().enumerate() {
-                        if idx > 0 {
-                            ", ".fmt(f)?
-                        }
-                        element.fmt(f)?
-                    }
-                    ']'.fmt(f)
-                }
-                ConValue::RangeExc(a, b) => write!(f, "{a}..{}", b + 1),
-                ConValue::RangeInc(a, b) => write!(f, "{a}..={b}"),
-                ConValue::Tuple(tuple) => {
-                    '('.fmt(f)?;
-                    for (idx, element) in tuple.iter().enumerate() {
-                        if idx > 0 {
-                            ", ".fmt(f)?
-                        }
-                        element.fmt(f)?
-                    }
-                    ')'.fmt(f)
-                }
-                ConValue::Function(func) => {
-                    write!(f, "{}", func.decl())
-                }
-                ConValue::BuiltIn(func) => {
-                    write!(f, "{}", func.description())
-                }
-            }
-        }
-    }
-}
+pub mod convalue;
 
 pub mod interpret;
 
-pub mod function {
-    //! Represents a block of code which lives inside the Interpreter
-
-    use super::{Callable, ConValue, Environment, Error, IResult, Interpret};
-    use cl_ast::{Function as FnDecl, Param, Sym};
-    use std::rc::Rc;
-    /// Represents a block of code which persists inside the Interpreter
-    #[derive(Clone, Debug)]
-    pub struct Function {
-        /// Stores the contents of the function declaration
-        decl: Rc<FnDecl>,
-        // /// Stores the enclosing scope of the function
-        // env: Box<Environment>,
-    }
-
-    impl Function {
-        pub fn new(decl: &FnDecl) -> Self {
-            Self { decl: decl.clone().into() }
-        }
-        pub fn decl(&self) -> &FnDecl {
-            &self.decl
-        }
-    }
-
-    impl Callable for Function {
-        fn name(&self) -> Sym {
-            let FnDecl { name, .. } = *self.decl;
-            name
-        }
-        fn call(&self, env: &mut Environment, args: &[ConValue]) -> IResult<ConValue> {
-            let FnDecl { name, bind, body, sign: _ } = &*self.decl;
-            // Check arg mapping
-            if args.len() != bind.len() {
-                return Err(Error::ArgNumber { want: bind.len(), got: args.len() });
-            }
-            let Some(body) = body else {
-                return Err(Error::NotDefined(*name));
-            };
-            // TODO: completely refactor data storage
-            let mut frame = env.frame("fn args");
-            for (Param { mutability: _, name }, value) in bind.iter().zip(args) {
-                frame.insert(*name, Some(value.clone()));
-            }
-            match body.interpret(&mut frame) {
-                Err(Error::Return(value)) => Ok(value),
-                Err(Error::Break(value)) => Err(Error::BadBreak(value)),
-                result => result,
-            }
-        }
-    }
-}
+pub mod function;
 
 pub mod builtin;
 
-pub mod env {
-    //! Lexical and non-lexical scoping for variables
-    use super::{
-        builtin::{BINARY, MISC, RANGE, UNARY},
-        convalue::ConValue,
-        error::{Error, IResult},
-        function::Function,
-        BuiltIn, Callable, Interpret,
-    };
-    use cl_ast::{Function as FnDecl, Sym};
-    use std::{
-        collections::HashMap,
-        fmt::Display,
-        ops::{Deref, DerefMut},
-    };
+pub mod env;
 
-    type StackFrame = HashMap<Sym, Option<ConValue>>;
-
-    /// Implements a nested lexical scope
-    #[derive(Clone, Debug)]
-    pub struct Environment {
-        frames: Vec<(StackFrame, &'static str)>,
-    }
-
-    impl Display for Environment {
-        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-            for (frame, name) in self.frames.iter().rev() {
-                writeln!(f, "--- {name} ---")?;
-                for (var, val) in frame {
-                    write!(f, "{var}: ")?;
-                    match val {
-                        Some(value) => writeln!(f, "\t{value}"),
-                        None => writeln!(f, "<undefined>"),
-                    }?
-                }
-            }
-            Ok(())
-        }
-    }
-    impl Default for Environment {
-        fn default() -> Self {
-            Self {
-                frames: vec![
-                    (to_hashmap(RANGE), "range ops"),
-                    (to_hashmap(UNARY), "unary ops"),
-                    (to_hashmap(BINARY), "binary ops"),
-                    (to_hashmap(MISC), "builtins"),
-                    (HashMap::new(), "globals"),
-                ],
-            }
-        }
-    }
-    fn to_hashmap(from: &[&'static dyn BuiltIn]) -> HashMap<Sym, Option<ConValue>> {
-        from.iter().map(|&v| (v.name(), Some(v.into()))).collect()
-    }
-
-    impl Environment {
-        pub fn new() -> Self {
-            Self::default()
-        }
-        /// Creates an [Environment] with no [builtins](super::builtin)
-        pub fn no_builtins(name: &'static str) -> Self {
-            Self { frames: vec![(Default::default(), name)] }
-        }
-
-        pub fn eval(&mut self, node: &impl Interpret) -> IResult<ConValue> {
-            node.interpret(self)
-        }
-
-        /// Calls a function inside the interpreter's scope,
-        /// and returns the result
-        pub fn call(&mut self, name: Sym, args: &[ConValue]) -> IResult<ConValue> {
-            // FIXME: Clone to satisfy the borrow checker
-            let function = self.get(name)?.clone();
-            function.call(self, args)
-        }
-        /// Enters a nested scope, returning a [`Frame`] stack-guard.
-        ///
-        /// [`Frame`] implements Deref/DerefMut for [`Environment`].
-        pub fn frame(&mut self, name: &'static str) -> Frame {
-            Frame::new(self, name)
-        }
-        /// Resolves a variable mutably.
-        ///
-        /// Returns a mutable reference to the variable's record, if it exists.
-        pub fn get_mut(&mut self, id: Sym) -> IResult<&mut Option<ConValue>> {
-            for (frame, _) in self.frames.iter_mut().rev() {
-                if let Some(var) = frame.get_mut(&id) {
-                    return Ok(var);
-                }
-            }
-            Err(Error::NotDefined(id))
-        }
-        /// Resolves a variable immutably.
-        ///
-        /// Returns a reference to the variable's contents, if it is defined and initialized.
-        pub fn get(&self, id: Sym) -> IResult<ConValue> {
-            for (frame, _) in self.frames.iter().rev() {
-                match frame.get(&id) {
-                    Some(Some(var)) => return Ok(var.clone()),
-                    Some(None) => return Err(Error::NotInitialized(id)),
-                    _ => (),
-                }
-            }
-            Err(Error::NotDefined(id))
-        }
-        /// Inserts a new [ConValue] into this [Environment]
-        pub fn insert(&mut self, id: Sym, value: Option<ConValue>) {
-            if let Some((frame, _)) = self.frames.last_mut() {
-                frame.insert(id, value);
-            }
-        }
-        /// A convenience function for registering a [FnDecl] as a [Function]
-        pub fn insert_fn(&mut self, decl: &FnDecl) {
-            let FnDecl { name, .. } = decl;
-            let (name, function) = (name, Some(Function::new(decl).into()));
-            if let Some((frame, _)) = self.frames.last_mut() {
-                frame.insert(*name, function);
-            }
-        }
-    }
-
-    /// Functions which aid in the implementation of [`Frame`]
-    impl Environment {
-        /// Enters a scope, creating a new namespace for variables
-        fn enter(&mut self, name: &'static str) -> &mut Self {
-            self.frames.push((Default::default(), name));
-            self
-        }
-
-        /// Exits the scope, destroying all local variables and
-        /// returning the outer scope, if there is one
-        fn exit(&mut self) -> &mut Self {
-            if self.frames.len() > 2 {
-                self.frames.pop();
-            }
-            self
-        }
-    }
-
-    /// Represents a stack frame
-    #[derive(Debug)]
-    pub struct Frame<'scope> {
-        scope: &'scope mut Environment,
-    }
-    impl<'scope> Frame<'scope> {
-        fn new(scope: &'scope mut Environment, name: &'static str) -> Self {
-            Self { scope: scope.enter(name) }
-        }
-    }
-    impl<'scope> Deref for Frame<'scope> {
-        type Target = Environment;
-        fn deref(&self) -> &Self::Target {
-            self.scope
-        }
-    }
-    impl<'scope> DerefMut for Frame<'scope> {
-        fn deref_mut(&mut self) -> &mut Self::Target {
-            self.scope
-        }
-    }
-    impl<'scope> Drop for Frame<'scope> {
-        fn drop(&mut self) {
-            self.scope.exit();
-        }
-    }
-}
-
-pub mod error {
-    //! The [Error] type represents any error thrown by the [Environment](super::Environment)
-
-    use cl_ast::Sym;
-
-    use super::convalue::ConValue;
-
-    pub type IResult<T> = Result<T, Error>;
-
-    /// Represents any error thrown by the [Environment](super::Environment)
-    #[derive(Clone, Debug)]
-    pub enum Error {
-        /// Propagate a Return value
-        Return(ConValue),
-        /// Propagate a Break value
-        Break(ConValue),
-        /// Break propagated across function bounds
-        BadBreak(ConValue),
-        /// Continue to the next iteration of a loop
-        Continue,
-        /// Underflowed the stack
-        StackUnderflow,
-        /// Exited the last scope
-        ScopeExit,
-        /// Type incompatibility
-        // TODO: store the type information in this error
-        TypeError,
-        /// In clause of For loop didn't yield a Range
-        NotIterable,
-        /// A value could not be indexed
-        NotIndexable,
-        /// An array index went out of bounds
-        OobIndex(usize, usize),
-        /// An expression is not assignable
-        NotAssignable,
-        /// A name was not defined in scope before being used
-        NotDefined(Sym),
-        /// A name was defined but not initialized
-        NotInitialized(Sym),
-        /// A value was called, but is not callable
-        NotCallable(ConValue),
-        /// A function was called with the wrong number of arguments
-        ArgNumber {
-            want: usize,
-            got: usize,
-        },
-        Outlined(Sym),
-    }
-
-    impl std::error::Error for Error {}
-    impl std::fmt::Display for Error {
-        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-            match self {
-                Error::Return(value) => write!(f, "return {value}"),
-                Error::Break(value) => write!(f, "break {value}"),
-                Error::BadBreak(value) => write!(f, "rogue break: {value}"),
-                Error::Continue => "continue".fmt(f),
-                Error::StackUnderflow => "Stack underflow".fmt(f),
-                Error::ScopeExit => "Exited the last scope. This is a logic bug.".fmt(f),
-                Error::TypeError => "Incompatible types".fmt(f),
-                Error::NotIterable => "`in` clause of `for` loop did not yield an iterable".fmt(f),
-                Error::NotIndexable => {
-                    write!(f, "expression cannot be indexed")
-                }
-                Error::OobIndex(idx, len) => {
-                    write!(f, "Index out of bounds: index was {idx}. but len is {len}")
-                }
-                Error::NotAssignable => {
-                    write!(f, "expression is not assignable")
-                }
-                Error::NotDefined(value) => {
-                    write!(f, "{value} not bound. Did you mean `let {value};`?")
-                }
-                Error::NotInitialized(value) => {
-                    write!(f, "{value} bound, but not initialized")
-                }
-                Error::NotCallable(value) => {
-                    write!(f, "{value} is not callable.")
-                }
-                Error::ArgNumber { want, got } => {
-                    write!(
-                        f,
-                        "Expected {want} argument{}, got {got}",
-                        if *want == 1 { "" } else { "s" }
-                    )
-                }
-                Error::Outlined(name) => {
-                    write!(f, "Module {name} specified, but not imported.")
-                }
-            }
-        }
-    }
-}
+pub mod error;
 
 #[cfg(test)]
 mod tests;

compiler/cl-interpret/src/tests.rs

@@ -1,5 +1,5 @@
 #![allow(unused_imports)]
-use crate::{env::Environment, convalue::ConValue, Interpret};
+use crate::{convalue::ConValue, env::Environment, Interpret};
 use cl_ast::*;
 use cl_lexer::Lexer;
 use cl_parser::Parser;
@@ -48,6 +48,7 @@ mod macros {
     //! ```
     #![allow(unused_macros)]
     use crate::IResult;
+    use cl_parser::parser::Parse;
 
     use super::*;
 
@@ -63,14 +64,14 @@ mod macros {
     ///
     /// Returns a `Result<`[`File`]`, ParseError>`
     pub macro file($($t:tt)*) {
-        Parser::new(Lexer::new(stringify!( $($t)* ))).file()
+        File::parse(&mut Parser::new(Lexer::new(stringify!( $($t)* ))))
     }
 
     /// Stringifies, lexes, and parses everything you give to it
     ///
     /// Returns a `Result<`[`Block`]`, ParseError>`
     pub macro block($($t:tt)*) {
-        Parser::new(Lexer::new(stringify!({ $($t)* }))).block()
+        Block::parse(&mut Parser::new(Lexer::new(stringify!({ $($t)* }))))
     }
 
     /// Evaluates a block of code in the given environment
@@ -177,6 +178,45 @@ mod let_declarations {
         env_eq!(env.x, 10);
         env_eq!(env.y, 10);
     }
+
+    #[test]
+    fn let_destructuring_tuple() {
+        let mut env = Environment::new();
+        assert_eval!(env,
+            let (x, y) = (10, 20);
+        );
+
+        env_eq!(env.x, 10);
+        env_eq!(env.y, 20);
+    }
+
+    #[test]
+    fn let_destructuring_array() {
+        let mut env = Environment::new();
+        assert_eval!(env,
+            let [x, y] = [10, 20];
+        );
+
+        env_eq!(env.x, 10);
+        env_eq!(env.y, 20);
+    }
+
+    #[test]
+    fn let_destructuring_nested() {
+        let mut env = Environment::new();
+        assert_eval!(env,
+            let (x, [one, two, three], (a, b, c))
+              = ('x', [1, 2, 3], ('a', 'b', 'c'));
+        );
+
+        env_eq!(env.x, 'x');
+        env_eq!(env.one, 1);
+        env_eq!(env.two, 2);
+        env_eq!(env.three, 3);
+        env_eq!(env.a, 'a');
+        env_eq!(env.b, 'b');
+        env_eq!(env.c, 'c');
+    }
 }
 
 mod fn_declarations {
@@ -187,7 +227,7 @@ mod fn_declarations {
         assert_eval!(env, fn empty_fn() {});
         // TODO: true equality for functions
         assert_eq!(
-            "fn empty_fn () {\n    \n}",
+            "fn empty_fn () {}",
             format!(
                 "{}",
                 env.get("empty_fn".into())
@@ -436,16 +476,17 @@ mod operators {
         env_eq!(env.y, 10);
         env_eq!(env.z, 10);
     }
-    #[test]
-    #[should_panic]
-    fn assignment_accounts_for_type() {
-        let mut env = Default::default();
-        assert_eval!(env,
-            let x = "a string";
-            let y = 0xdeadbeef;
-            y = x; // should crash: type error
-        );
-    }
+    // Test is disabled, since new assignment system intentionally does not care.
+    // #[test]
+    // #[should_panic]
+    // fn assignment_accounts_for_type() {
+    //     let mut env = Default::default();
+    //     assert_eval!(env,
+    //         let x = "a string";
+    //         let y = 0xdeadbeef;
+    //         y = x; // should crash: type error
+    //     );
+    // }
     #[test]
     fn precedence() {
         let mut env = Default::default();
@@ -468,6 +509,56 @@ mod operators {
     }
 }
 
+mod control_flow {
+    use super::*;
+
+    #[test]
+    fn if_evaluates_pass_block_on_true() {
+        let mut env = Default::default();
+        assert_eval!(env,
+            let evaluated = if true { "pass" } else { "fail" }
+        );
+        env_eq!(env.evaluated, "pass");
+    }
+
+    #[test]
+    fn if_evaluates_fail_block_on_false() {
+        let mut env = Default::default();
+        assert_eval!(env,
+            let evaluated = if false { "pass" } else { "fail" }
+        );
+        env_eq!(env.evaluated, "fail");
+    }
+
+    #[test]
+    fn match_evaluates_in_order() {
+        let mut env = Default::default();
+        assert_eval!(env,
+            let x = '\u{1f988}';
+            let passed = match x {
+                '\u{1f988}' => true,
+                _ => false,
+            };
+        );
+        env_eq!(env.passed, true);
+    }
+
+    #[test]
+    fn match_sinkoles_underscore_patterns() {
+        let mut env = Default::default();
+        assert_eval!(env,
+            let x = '\u{1f988}';
+            let passed = match x {
+                _ => true,
+                '\u{1f988}' => false,
+            };
+        );
+        env_eq!(env.passed, true);
+    }
+
+    //TODO: test other control flow constructs like loops, while-else, etc.
+}
+
 #[allow(dead_code)]
 fn test_template() {
     let mut env = Default::default();

compiler/cl-lexer/src/lib.rs

@@ -23,7 +23,7 @@ pub mod lexer_iter {
     pub struct LexerIter<'t> {
         lexer: Lexer<'t>,
     }
-    impl<'t> Iterator for LexerIter<'t> {
+    impl Iterator for LexerIter<'_> {
         type Item = LResult<Token>;
         fn next(&mut self) -> Option<Self::Item> {
             match self.lexer.scan() {
@@ -97,33 +97,33 @@ impl<'t> Lexer<'t> {
     /// Scans through the text, searching for the next [Token]
     pub fn scan(&mut self) -> LResult<Token> {
         match self.skip_whitespace().peek()? {
-            '{' => self.consume()?.produce_op(Punct::LCurly),
-            '}' => self.consume()?.produce_op(Punct::RCurly),
-            '[' => self.consume()?.produce_op(Punct::LBrack),
-            ']' => self.consume()?.produce_op(Punct::RBrack),
-            '(' => self.consume()?.produce_op(Punct::LParen),
-            ')' => self.consume()?.produce_op(Punct::RParen),
+            '{' => self.consume()?.produce_op(Kind::LCurly),
+            '}' => self.consume()?.produce_op(Kind::RCurly),
+            '[' => self.consume()?.produce_op(Kind::LBrack),
+            ']' => self.consume()?.produce_op(Kind::RBrack),
+            '(' => self.consume()?.produce_op(Kind::LParen),
+            ')' => self.consume()?.produce_op(Kind::RParen),
             '&' => self.consume()?.amp(),
-            '@' => self.consume()?.produce_op(Punct::At),
-            '\\' => self.consume()?.produce_op(Punct::Backslash),
+            '@' => self.consume()?.produce_op(Kind::At),
+            '\\' => self.consume()?.produce_op(Kind::Backslash),
             '!' => self.consume()?.bang(),
             '|' => self.consume()?.bar(),
             ':' => self.consume()?.colon(),
-            ',' => self.consume()?.produce_op(Punct::Comma),
+            ',' => self.consume()?.produce_op(Kind::Comma),
             '.' => self.consume()?.dot(),
             '=' => self.consume()?.equal(),
-            '`' => self.consume()?.produce_op(Punct::Grave),
+            '`' => self.consume()?.produce_op(Kind::Grave),
             '>' => self.consume()?.greater(),
             '#' => self.consume()?.hash(),
             '<' => self.consume()?.less(),
             '-' => self.consume()?.minus(),
             '+' => self.consume()?.plus(),
-            '?' => self.consume()?.produce_op(Punct::Question),
+            '?' => self.consume()?.produce_op(Kind::Question),
             '%' => self.consume()?.rem(),
-            ';' => self.consume()?.produce_op(Punct::Semi),
+            ';' => self.consume()?.produce_op(Kind::Semi),
             '/' => self.consume()?.slash(),
             '*' => self.consume()?.star(),
-            '~' => self.consume()?.produce_op(Punct::Tilde),
+            '~' => self.consume()?.produce_op(Kind::Tilde),
             '^' => self.consume()?.xor(),
             '0' => self.consume()?.int_with_base(),
             '1'..='9' => self.digits::<10>(),
@@ -157,14 +157,14 @@ impl<'t> Lexer<'t> {
             .copied()
             .ok_or(Error::end_of_file(self.line(), self.col()))
     }
-    fn produce(&mut self, kind: TokenKind, data: impl Into<TokenData>) -> LResult<Token> {
+    fn produce(&mut self, kind: Kind, data: impl Into<TokenData>) -> LResult<Token> {
         let loc = self.start_loc;
         self.start_loc = self.current_loc;
         self.start = self.current;
         Ok(Token::new(kind, data, loc.0, loc.1))
     }
-    fn produce_op(&mut self, kind: Punct) -> LResult<Token> {
-        self.produce(TokenKind::Punct(kind), ())
+    fn produce_op(&mut self, kind: Kind) -> LResult<Token> {
+        self.produce(kind, ())
     }
     fn skip_whitespace(&mut self) -> &mut Self {
         while let Ok(c) = self.peek() {
@@ -192,145 +192,154 @@ impl<'t> Lexer<'t> {
     }
 }
 /// Digraphs and trigraphs
-impl<'t> Lexer<'t> {
+impl Lexer<'_> {
     fn amp(&mut self) -> LResult<Token> {
         match self.peek() {
-            Ok('&') => self.consume()?.produce_op(Punct::AmpAmp),
-            Ok('=') => self.consume()?.produce_op(Punct::AmpEq),
-            _ => self.produce_op(Punct::Amp),
+            Ok('&') => self.consume()?.produce_op(Kind::AmpAmp),
+            Ok('=') => self.consume()?.produce_op(Kind::AmpEq),
+            _ => self.produce_op(Kind::Amp),
         }
     }
     fn bang(&mut self) -> LResult<Token> {
         match self.peek() {
-            Ok('!') => self.consume()?.produce_op(Punct::BangBang),
-            Ok('=') => self.consume()?.produce_op(Punct::BangEq),
-            _ => self.produce_op(Punct::Bang),
+            Ok('!') => self.consume()?.produce_op(Kind::BangBang),
+            Ok('=') => self.consume()?.produce_op(Kind::BangEq),
+            _ => self.produce_op(Kind::Bang),
         }
     }
     fn bar(&mut self) -> LResult<Token> {
         match self.peek() {
-            Ok('|') => self.consume()?.produce_op(Punct::BarBar),
-            Ok('=') => self.consume()?.produce_op(Punct::BarEq),
-            _ => self.produce_op(Punct::Bar),
+            Ok('|') => self.consume()?.produce_op(Kind::BarBar),
+            Ok('=') => self.consume()?.produce_op(Kind::BarEq),
+            _ => self.produce_op(Kind::Bar),
         }
     }
     fn colon(&mut self) -> LResult<Token> {
         match self.peek() {
-            Ok(':') => self.consume()?.produce_op(Punct::ColonColon),
-            _ => self.produce_op(Punct::Colon),
+            Ok(':') => self.consume()?.produce_op(Kind::ColonColon),
+            _ => self.produce_op(Kind::Colon),
         }
     }
     fn dot(&mut self) -> LResult<Token> {
         match self.peek() {
             Ok('.') => {
                 if let Ok('=') = self.consume()?.peek() {
-                    self.consume()?.produce_op(Punct::DotDotEq)
+                    self.consume()?.produce_op(Kind::DotDotEq)
                 } else {
-                    self.produce_op(Punct::DotDot)
+                    self.produce_op(Kind::DotDot)
                 }
             }
-            _ => self.produce_op(Punct::Dot),
+            _ => self.produce_op(Kind::Dot),
         }
     }
     fn equal(&mut self) -> LResult<Token> {
         match self.peek() {
-            Ok('=') => self.consume()?.produce_op(Punct::EqEq),
-            Ok('>') => self.consume()?.produce_op(Punct::FatArrow),
-            _ => self.produce_op(Punct::Eq),
+            Ok('=') => self.consume()?.produce_op(Kind::EqEq),
+            Ok('>') => self.consume()?.produce_op(Kind::FatArrow),
+            _ => self.produce_op(Kind::Eq),
         }
     }
     fn greater(&mut self) -> LResult<Token> {
         match self.peek() {
-            Ok('=') => self.consume()?.produce_op(Punct::GtEq),
+            Ok('=') => self.consume()?.produce_op(Kind::GtEq),
             Ok('>') => {
                 if let Ok('=') = self.consume()?.peek() {
-                    self.consume()?.produce_op(Punct::GtGtEq)
+                    self.consume()?.produce_op(Kind::GtGtEq)
                 } else {
-                    self.produce_op(Punct::GtGt)
+                    self.produce_op(Kind::GtGt)
                 }
             }
-            _ => self.produce_op(Punct::Gt),
+            _ => self.produce_op(Kind::Gt),
         }
     }
     fn hash(&mut self) -> LResult<Token> {
         match self.peek() {
-            Ok('!') => self.consume()?.produce_op(Punct::HashBang),
-            _ => self.produce_op(Punct::Hash),
+            Ok('!') => self.consume()?.hashbang(),
+            _ => self.produce_op(Kind::Hash),
+        }
+    }
+    fn hashbang(&mut self) -> LResult<Token> {
+        match self.peek() {
+            Ok('/' | '\'') => self.line_comment(),
+            _ => self.produce_op(Kind::HashBang),
         }
     }
     fn less(&mut self) -> LResult<Token> {
         match self.peek() {
-            Ok('=') => self.consume()?.produce_op(Punct::LtEq),
+            Ok('=') => self.consume()?.produce_op(Kind::LtEq),
             Ok('<') => {
                 if let Ok('=') = self.consume()?.peek() {
-                    self.consume()?.produce_op(Punct::LtLtEq)
+                    self.consume()?.produce_op(Kind::LtLtEq)
                 } else {
-                    self.produce_op(Punct::LtLt)
+                    self.produce_op(Kind::LtLt)
                 }
             }
-            _ => self.produce_op(Punct::Lt),
+            _ => self.produce_op(Kind::Lt),
         }
     }
     fn minus(&mut self) -> LResult<Token> {
         match self.peek() {
-            Ok('=') => self.consume()?.produce_op(Punct::MinusEq),
-            Ok('>') => self.consume()?.produce_op(Punct::Arrow),
-            _ => self.produce_op(Punct::Minus),
+            Ok('=') => self.consume()?.produce_op(Kind::MinusEq),
+            Ok('>') => self.consume()?.produce_op(Kind::Arrow),
+            _ => self.produce_op(Kind::Minus),
         }
     }
     fn plus(&mut self) -> LResult<Token> {
         match self.peek() {
-            Ok('=') => self.consume()?.produce_op(Punct::PlusEq),
-            _ => self.produce_op(Punct::Plus),
+            Ok('=') => self.consume()?.produce_op(Kind::PlusEq),
+            _ => self.produce_op(Kind::Plus),
         }
     }
     fn rem(&mut self) -> LResult<Token> {
         match self.peek() {
-            Ok('=') => self.consume()?.produce_op(Punct::RemEq),
-            _ => self.produce_op(Punct::Rem),
+            Ok('=') => self.consume()?.produce_op(Kind::RemEq),
+            _ => self.produce_op(Kind::Rem),
         }
     }
     fn slash(&mut self) -> LResult<Token> {
         match self.peek() {
-            Ok('=') => self.consume()?.produce_op(Punct::SlashEq),
+            Ok('=') => self.consume()?.produce_op(Kind::SlashEq),
             Ok('/') => self.consume()?.line_comment(),
             Ok('*') => self.consume()?.block_comment(),
-            _ => self.produce_op(Punct::Slash),
+            _ => self.produce_op(Kind::Slash),
         }
     }
     fn star(&mut self) -> LResult<Token> {
         match self.peek() {
-            Ok('=') => self.consume()?.produce_op(Punct::StarEq),
-            _ => self.produce_op(Punct::Star),
+            Ok('=') => self.consume()?.produce_op(Kind::StarEq),
+            _ => self.produce_op(Kind::Star),
         }
     }
     fn xor(&mut self) -> LResult<Token> {
         match self.peek() {
-            Ok('=') => self.consume()?.produce_op(Punct::XorEq),
-            Ok('^') => self.consume()?.produce_op(Punct::XorXor),
-            _ => self.produce_op(Punct::Xor),
+            Ok('=') => self.consume()?.produce_op(Kind::XorEq),
+            Ok('^') => self.consume()?.produce_op(Kind::XorXor),
+            _ => self.produce_op(Kind::Xor),
         }
     }
 }
 /// Comments
-impl<'t> Lexer<'t> {
+impl Lexer<'_> {
     fn line_comment(&mut self) -> LResult<Token> {
+        let mut comment = String::new();
         while Ok('\n') != self.peek() {
-            self.consume()?;
+            comment.push(self.next()?);
         }
-        self.produce(Kind::Comment, ())
+        self.produce(Kind::Comment, comment)
     }
     fn block_comment(&mut self) -> LResult<Token> {
+        let mut comment = String::new();
         while let Ok(c) = self.next() {
-            if '*' == c && Ok('/') == self.next() {
+            if '*' == c && Ok('/') == self.peek() {
                 break;
             }
+            comment.push(c);
         }
-        self.produce(Kind::Comment, ())
+        self.consume()?.produce(Kind::Comment, comment)
     }
 }
 /// Identifiers
-impl<'t> Lexer<'t> {
+impl Lexer<'_> {
     fn identifier(&mut self) -> LResult<Token> {
         let mut out = String::from(self.xid_start()?);
         while let Ok(c) = self.xid_continue() {
@@ -362,23 +371,39 @@ impl<'t> Lexer<'t> {
     }
 }
 /// Integers
-impl<'t> Lexer<'t> {
+impl Lexer<'_> {
     fn int_with_base(&mut self) -> LResult<Token> {
         match self.peek() {
             Ok('x') => self.consume()?.digits::<16>(),
             Ok('d') => self.consume()?.digits::<10>(),
             Ok('o') => self.consume()?.digits::<8>(),
             Ok('b') => self.consume()?.digits::<2>(),
-            Ok('0'..='9') => self.digits::<10>(),
+            Ok('0'..='9' | '.') => self.digits::<10>(),
             _ => self.produce(Kind::Literal, 0),
         }
     }
     fn digits<const B: u32>(&mut self) -> LResult<Token> {
-        let mut value = self.digit::<B>()? as u128;
+        let mut value = 0;
         while let Ok(true) = self.peek().as_ref().map(char::is_ascii_alphanumeric) {
             value = value * B as u128 + self.digit::<B>()? as u128;
         }
-        self.produce(Kind::Literal, value)
+        // TODO: find a better way to handle floats in the tokenizer
+        match self.peek() {
+            Ok('.') => {
+                // FIXME: hack: 0.. is not [0.0, '.']
+                if let Ok('.') = self.clone().consume()?.next() {
+                    return self.produce(Kind::Literal, value);
+                }
+                let mut float = format!("{value}.");
+                self.consume()?;
+                while let Ok(true) = self.peek().as_ref().map(char::is_ascii_digit) {
+                    float.push(self.iter.next().unwrap_or_default());
+                }
+                let float = f64::from_str(&float).expect("must be parsable as float");
+                self.produce(Kind::Literal, float)
+            }
+            _ => self.produce(Kind::Literal, value),
+        }
     }
     fn digit<const B: u32>(&mut self) -> LResult<u32> {
         let digit = self.peek()?;
@@ -389,7 +414,7 @@ impl<'t> Lexer<'t> {
     }
 }
 /// Strings and characters
-impl<'t> Lexer<'t> {
+impl Lexer<'_> {
     fn string(&mut self) -> LResult<Token> {
         let mut value = String::new();
         while '"'

compiler/cl-lexer/src/tests.rs

@@ -110,7 +110,7 @@ mod string {
 }
 mod punct {
     macro op($op:ident) {
-        TokenKind::Punct(Punct::$op)
+        TokenKind::$op
     }
 
     use super::*;

compiler/cl-parser/src/error.rs

@@ -99,6 +99,7 @@ pub enum Parsing {
     BinaryKind,
     Unary,
     UnaryKind,
+    Cast,
     Index,
     Structor,
     Fielder,
@@ -118,6 +119,10 @@ pub enum Parsing {
     Break,
     Return,
     Continue,
+
+    Pattern,
+    Match,
+    MatchArm,
 }
 
 impl Display for Error {
@@ -204,6 +209,7 @@ impl Display for Parsing {
             Parsing::BinaryKind => "a binary operator",
             Parsing::Unary => "a unary expression",
             Parsing::UnaryKind => "a unary operator",
+            Parsing::Cast => "an `as`-casting expression",
             Parsing::Index => "an indexing expression",
             Parsing::Structor => "a struct constructor expression",
             Parsing::Fielder => "a struct field expression",
@@ -223,6 +229,10 @@ impl Display for Parsing {
             Parsing::Break => "a break expression",
             Parsing::Return => "a return expression",
             Parsing::Continue => "a continue expression",
+
+            Parsing::Pattern => "a pattern",
+            Parsing::Match => "a match expression",
+            Parsing::MatchArm => "a match arm",
         }
         .fmt(f)
     }

compiler/cl-parser/src/inliner.rs

@@ -85,7 +85,7 @@ impl Fold for ModuleInliner {
             Ok(file) => file,
         };
 
-        let kind = match Parser::new(Lexer::new(&file)).file() {
+        let kind = match Parser::new(Lexer::new(&file)).parse() {
             Err(e) => return self.handle_parse_error(e),
             Ok(file) => ModuleKind::Inline(file),
         };

compiler/cl-parser/src/parser/prec.rs

@@ -0,0 +1,381 @@
+//! Parses an [ExprKind] using a modified pratt parser
+//!
+//! See also: [Expr::parse], [ExprKind::parse]
+//!
+//! Implementer's note: [ExprKind::parse] is the public API for parsing [ExprKind]s.
+//! Do not call it from within this function.
+
+use super::{Parse, *};
+
+/// Parses an [ExprKind]
+pub fn exprkind(p: &mut Parser, power: u8) -> PResult<ExprKind> {
+    let parsing = Parsing::ExprKind;
+
+    // Prefix expressions
+    let mut head = match p.peek_kind(Parsing::Unary)? {
+        literal_like!() => Literal::parse(p)?.into(),
+        path_like!() => exprkind_pathlike(p)?,
+        TokenKind::Amp | TokenKind::AmpAmp => AddrOf::parse(p)?.into(),
+        TokenKind::Grave => Quote::parse(p)?.into(),
+        TokenKind::LCurly => Block::parse(p)?.into(),
+        TokenKind::LBrack => exprkind_arraylike(p)?,
+        TokenKind::LParen => exprkind_tuplelike(p)?,
+        TokenKind::Let => Let::parse(p)?.into(),
+        TokenKind::Match => Match::parse(p)?.into(),
+        TokenKind::While => ExprKind::While(While::parse(p)?),
+        TokenKind::If => ExprKind::If(If::parse(p)?),
+        TokenKind::For => ExprKind::For(For::parse(p)?),
+        TokenKind::Break => ExprKind::Break(Break::parse(p)?),
+        TokenKind::Return => ExprKind::Return(Return::parse(p)?),
+        TokenKind::Continue => {
+            p.consume_peeked();
+            ExprKind::Continue
+        }
+
+        op => {
+            let (kind, prec) = from_prefix(op).ok_or_else(|| p.error(Unexpected(op), parsing))?;
+            let ((), after) = prec.prefix().expect("should have a precedence");
+            p.consume_peeked();
+            Unary { kind, tail: exprkind(p, after)?.into() }.into()
+        }
+    };
+
+    fn from_postfix(op: TokenKind) -> Option<Precedence> {
+        Some(match op {
+            TokenKind::LBrack => Precedence::Index,
+            TokenKind::LParen => Precedence::Call,
+            TokenKind::Dot => Precedence::Member,
+            _ => None?,
+        })
+    }
+
+    while let Ok(op) = p.peek_kind(parsing) {
+        // Postfix expressions
+        if let Some((before, ())) = from_postfix(op).and_then(Precedence::postfix) {
+            if before < power {
+                break;
+            }
+            p.consume_peeked();
+
+            head = match op {
+                TokenKind::LBrack => {
+                    let indices =
+                        sep(Expr::parse, TokenKind::Comma, TokenKind::RBrack, parsing)(p)?;
+                    p.match_type(TokenKind::RBrack, parsing)?;
+                    ExprKind::Index(Index { head: head.into(), indices })
+                }
+                TokenKind::LParen => {
+                    let exprs = sep(Expr::parse, TokenKind::Comma, TokenKind::RParen, parsing)(p)?;
+                    p.match_type(TokenKind::RParen, parsing)?;
+                    Binary { kind: BinaryKind::Call, parts: (head, Tuple { exprs }.into()).into() }
+                        .into()
+                }
+                TokenKind::Dot => {
+                    let kind = MemberKind::parse(p)?;
+                    Member { head: Box::new(head), kind }.into()
+                }
+                _ => Err(p.error(Unexpected(op), parsing))?,
+            };
+            continue;
+        }
+        // infix expressions
+        if let Some((kind, prec)) = from_infix(op) {
+            let (before, after) = prec.infix().expect("should have a precedence");
+            if before < power {
+                break;
+            }
+            p.consume_peeked();
+
+            let tail = exprkind(p, after)?;
+            head = Binary { kind, parts: (head, tail).into() }.into();
+            continue;
+        }
+
+        if let Some((kind, prec)) = from_modify(op) {
+            let (before, after) = prec.infix().expect("should have a precedence");
+            if before < power {
+                break;
+            }
+            p.consume_peeked();
+
+            let tail = exprkind(p, after)?;
+            head = Modify { kind, parts: (head, tail).into() }.into();
+            continue;
+        }
+
+        if let TokenKind::Eq = op {
+            let (before, after) = Precedence::Assign
+                .infix()
+                .expect("should have a precedence");
+            if before < power {
+                break;
+            }
+            p.consume_peeked();
+
+            let tail = exprkind(p, after)?;
+            head = Assign { parts: (head, tail).into() }.into();
+            continue;
+        }
+
+        if let TokenKind::As = op {
+            let before = Precedence::Cast.level();
+            if before < power {
+                break;
+            }
+            p.consume_peeked();
+
+            let ty = Ty::parse(p)?;
+            head = Cast { head: head.into(), ty }.into();
+            continue;
+        }
+
+        break;
+    }
+
+    Ok(head)
+}
+
+/// [Array] = '[' ([Expr] ',')* [Expr]? ']'
+///
+/// Array and ArrayRef are ambiguous until the second token,
+/// so they can't be independent subexpressions
+fn exprkind_arraylike(p: &mut Parser) -> PResult<ExprKind> {
+    const P: Parsing = Parsing::Array;
+    const START: TokenKind = TokenKind::LBrack;
+    const END: TokenKind = TokenKind::RBrack;
+
+    p.match_type(START, P)?;
+    let out = match p.peek_kind(P)? {
+        END => Array { values: vec![] }.into(),
+        _ => exprkind_array_rep(p)?,
+    };
+    p.match_type(END, P)?;
+    Ok(out)
+}
+
+/// [ArrayRep] = `[` [Expr] `;` [Expr] `]`
+fn exprkind_array_rep(p: &mut Parser) -> PResult<ExprKind> {
+    const P: Parsing = Parsing::Array;
+    const END: TokenKind = TokenKind::RBrack;
+
+    let first = Expr::parse(p)?;
+    Ok(match p.peek_kind(P)? {
+        TokenKind::Semi => ArrayRep {
+            value: first.kind.into(),
+            repeat: {
+                p.consume_peeked();
+                Box::new(exprkind(p, 0)?)
+            },
+        }
+        .into(),
+        TokenKind::RBrack => Array { values: vec![first] }.into(),
+        TokenKind::Comma => Array {
+            values: {
+                p.consume_peeked();
+                let mut out = vec![first];
+                out.extend(sep(Expr::parse, TokenKind::Comma, END, P)(p)?);
+                out
+            },
+        }
+        .into(),
+        ty => Err(p.error(Unexpected(ty), P))?,
+    })
+}
+
+/// [Group] = `(`([Empty](ExprKind::Empty)|[Expr]|[Tuple])`)`
+///
+/// [ExprKind::Empty] and [Group] are special cases of [Tuple]
+fn exprkind_tuplelike(p: &mut Parser) -> PResult<ExprKind> {
+    p.match_type(TokenKind::LParen, Parsing::Group)?;
+    let out = match p.peek_kind(Parsing::Group)? {
+        TokenKind::RParen => Ok(ExprKind::Empty),
+        _ => exprkind_group(p),
+    };
+    p.match_type(TokenKind::RParen, Parsing::Group)?;
+    out
+}
+
+/// [Group] = `(`([Empty](ExprKind::Empty)|[Expr]|[Tuple])`)`
+fn exprkind_group(p: &mut Parser) -> PResult<ExprKind> {
+    let first = Expr::parse(p)?;
+    match p.peek_kind(Parsing::Group)? {
+        TokenKind::Comma => {
+            let mut exprs = vec![first];
+            p.consume_peeked();
+            while TokenKind::RParen != p.peek_kind(Parsing::Tuple)? {
+                exprs.push(Expr::parse(p)?);
+                match p.peek_kind(Parsing::Tuple)? {
+                    TokenKind::Comma => p.consume_peeked(),
+                    _ => break,
+                };
+            }
+            Ok(Tuple { exprs }.into())
+        }
+        _ => Ok(Group { expr: first.kind.into() }.into()),
+    }
+}
+
+/// Parses an expression beginning with a [Path] (i.e. [Path] or [Structor])
+fn exprkind_pathlike(p: &mut Parser) -> PResult<ExprKind> {
+    let head = Path::parse(p)?;
+    Ok(match p.match_type(TokenKind::Colon, Parsing::Path) {
+        Ok(_) => ExprKind::Structor(structor_body(p, head)?),
+        Err(_) => ExprKind::Path(head),
+    })
+}
+
+/// [Structor]Body = `{` ([Fielder] `,`)* [Fielder]? `}`
+fn structor_body(p: &mut Parser, to: Path) -> PResult<Structor> {
+    let init = delim(
+        sep(
+            Fielder::parse,
+            TokenKind::Comma,
+            CURLIES.1,
+            Parsing::Structor,
+        ),
+        CURLIES,
+        Parsing::Structor,
+    )(p)?;
+
+    Ok(Structor { to, init })
+}
+
+/// Precedence provides a total ordering among operators
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+pub enum Precedence {
+    Assign,
+    Logic,
+    Compare,
+    Range,
+    Bitwise,
+    Shift,
+    Factor,
+    Term,
+    Unary,
+    Index,
+    Cast,
+    Member, // left-associative
+    Call,
+    Highest,
+}
+
+impl Precedence {
+    #[inline]
+    pub const fn level(self) -> u8 {
+        (self as u8) << 1
+    }
+
+    pub fn prefix(self) -> Option<((), u8)> {
+        match self {
+            Self::Assign => Some(((), self.level())),
+            Self::Unary => Some(((), self.level())),
+            _ => None,
+        }
+    }
+
+    pub fn infix(self) -> Option<(u8, u8)> {
+        let level = self.level();
+        match self {
+            Self::Unary => None,
+            Self::Assign => Some((level + 1, level)),
+            _ => Some((level, level + 1)),
+        }
+    }
+
+    pub fn postfix(self) -> Option<(u8, ())> {
+        match self {
+            Self::Index | Self::Call | Self::Member => Some((self.level(), ())),
+            _ => None,
+        }
+    }
+}
+
+impl From<ModifyKind> for Precedence {
+    fn from(_value: ModifyKind) -> Self {
+        Precedence::Assign
+    }
+}
+
+impl From<BinaryKind> for Precedence {
+    fn from(value: BinaryKind) -> Self {
+        use BinaryKind as Op;
+        match value {
+            Op::Call => Precedence::Call,
+            Op::Mul | Op::Div | Op::Rem => Precedence::Term,
+            Op::Add | Op::Sub => Precedence::Factor,
+            Op::Shl | Op::Shr => Precedence::Shift,
+            Op::BitAnd | Op::BitOr | Op::BitXor => Precedence::Bitwise,
+            Op::LogAnd | Op::LogOr | Op::LogXor => Precedence::Logic,
+            Op::RangeExc | Op::RangeInc => Precedence::Range,
+            Op::Lt | Op::LtEq | Op::Equal | Op::NotEq | Op::GtEq | Op::Gt => Precedence::Compare,
+        }
+    }
+}
+
+impl From<UnaryKind> for Precedence {
+    fn from(value: UnaryKind) -> Self {
+        use UnaryKind as Op;
+        match value {
+            Op::Loop => Precedence::Assign,
+            Op::Deref | Op::Neg | Op::Not | Op::At | Op::Tilde => Precedence::Unary,
+        }
+    }
+}
+
+/// Creates helper functions for turning TokenKinds into AST operators
+macro operator($($name:ident ($takes:ident => $returns:ident) {$($t:ident => $p:ident),*$(,)?};)*) {$(
+    pub fn $name (value: $takes) -> Option<($returns, Precedence)> {
+        match value {
+            $($takes::$t => Some(($returns::$p, Precedence::from($returns::$p))),)*
+            _ => None?,
+        }
+    })*
+}
+
+operator! {
+    from_prefix (TokenKind => UnaryKind) {
+        Loop => Loop,
+        Star => Deref,
+        Minus => Neg,
+        Bang => Not,
+        At => At,
+        Tilde => Tilde,
+    };
+
+    from_modify(TokenKind => ModifyKind) {
+        AmpEq => And,
+        BarEq => Or,
+        XorEq => Xor,
+        LtLtEq => Shl,
+        GtGtEq => Shr,
+        PlusEq => Add,
+        MinusEq => Sub,
+        StarEq => Mul,
+        SlashEq => Div,
+        RemEq => Rem,
+    };
+
+    from_infix (TokenKind => BinaryKind) {
+        Lt => Lt,
+        LtEq => LtEq,
+        EqEq => Equal,
+        BangEq => NotEq,
+        GtEq => GtEq,
+        Gt => Gt,
+        DotDot => RangeExc,
+        DotDotEq => RangeInc,
+        AmpAmp => LogAnd,
+        BarBar => LogOr,
+        XorXor => LogXor,
+        Amp => BitAnd,
+        Bar => BitOr,
+        Xor => BitXor,
+        LtLt => Shl,
+        GtGt => Shr,
+        Plus => Add,
+        Minus => Sub,
+        Star => Mul,
+        Slash => Div,
+        Rem => Rem,
+    };
+}

compiler/cl-repl/examples/yaml.rs

@@ -1,5 +1,6 @@
 //! Pretty prints a conlang AST in yaml
 
+use cl_ast::Stmt;
 use cl_lexer::Lexer;
 use cl_parser::Parser;
 use repline::{error::Error as RlError, Repline};
@@ -19,7 +20,7 @@ fn main() -> Result<(), Box<dyn Error>> {
         };
 
         let mut parser = Parser::new(Lexer::new(&line));
-        let code = match parser.stmt() {
+        let code = match parser.parse::<Stmt>() {
             Ok(code) => {
                 rl.accept();
                 code
@@ -119,19 +120,19 @@ pub mod yamler {
         }
     }
 
-    impl<'y> Deref for Section<'y> {
+    impl Deref for Section<'_> {
         type Target = Yamler;
         fn deref(&self) -> &Self::Target {
             self.yamler
         }
     }
-    impl<'y> DerefMut for Section<'y> {
+    impl DerefMut for Section<'_> {
         fn deref_mut(&mut self) -> &mut Self::Target {
             self.yamler
         }
     }
 
-    impl<'y> Drop for Section<'y> {
+    impl Drop for Section<'_> {
         fn drop(&mut self) {
             let Self { yamler } = self;
             yamler.decrease();
@@ -363,22 +364,11 @@ pub mod yamlify {
         fn yaml(&self, y: &mut Yamler) {
             match self {
                 StmtKind::Empty => y,
-                StmtKind::Local(s) => y.yaml(s),
                 StmtKind::Item(s) => y.yaml(s),
                 StmtKind::Expr(s) => y.yaml(s),
             };
         }
     }
-    impl Yamlify for Let {
-        fn yaml(&self, y: &mut Yamler) {
-            let Self { mutable, name, ty, init } = self;
-            y.key("Let")
-                .pair("name", name)
-                .yaml(mutable)
-                .pair("ty", ty)
-                .pair("init", init);
-        }
-    }
     impl Yamlify for Expr {
         fn yaml(&self, y: &mut Yamler) {
             let Self { extents: _, kind } = self;
@@ -388,10 +378,14 @@ pub mod yamlify {
     impl Yamlify for ExprKind {
         fn yaml(&self, y: &mut Yamler) {
             match self {
+                ExprKind::Quote(k) => k.yaml(y),
+                ExprKind::Let(k) => k.yaml(y),
+                ExprKind::Match(k) => k.yaml(y),
                 ExprKind::Assign(k) => k.yaml(y),
                 ExprKind::Modify(k) => k.yaml(y),
                 ExprKind::Binary(k) => k.yaml(y),
                 ExprKind::Unary(k) => k.yaml(y),
+                ExprKind::Cast(k) => k.yaml(y),
                 ExprKind::Member(k) => k.yaml(y),
                 ExprKind::Index(k) => k.yaml(y),
                 ExprKind::Structor(k) => k.yaml(y),
@@ -404,16 +398,71 @@ pub mod yamlify {
                 ExprKind::Empty => {}
                 ExprKind::Group(k) => k.yaml(y),
                 ExprKind::Tuple(k) => k.yaml(y),
-                ExprKind::Loop(k) => k.yaml(y),
                 ExprKind::While(k) => k.yaml(y),
                 ExprKind::If(k) => k.yaml(y),
                 ExprKind::For(k) => k.yaml(y),
                 ExprKind::Break(k) => k.yaml(y),
                 ExprKind::Return(k) => k.yaml(y),
-                ExprKind::Continue(k) => k.yaml(y),
+                ExprKind::Continue => {
+                    y.key("Continue");
+                }
             }
         }
     }
+    impl Yamlify for Quote {
+        fn yaml(&self, y: &mut Yamler) {
+            y.key("Quote").value(self);
+        }
+    }
+    impl Yamlify for Let {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { mutable, name, ty, init } = self;
+            y.key("Let")
+                .pair("name", name)
+                .yaml(mutable)
+                .pair("ty", ty)
+                .pair("init", init);
+        }
+    }
+
+    impl Yamlify for Pattern {
+        fn yaml(&self, y: &mut Yamler) {
+            match self {
+                Pattern::Path(path) => y.value(path),
+                Pattern::Literal(literal) => y.value(literal),
+                Pattern::Ref(mutability, pattern) => {
+                    y.pair("mutability", mutability).pair("subpattern", pattern)
+                }
+                Pattern::Tuple(patterns) => y.key("Tuple").yaml(patterns),
+                Pattern::Array(patterns) => y.key("Array").yaml(patterns),
+                Pattern::Struct(path, items) => {
+                    {
+                        let mut y = y.key("Struct");
+                        y.pair("name", path);
+                        for (name, item) in items {
+                            y.pair(name, item);
+                        }
+                    }
+                    y
+                }
+            };
+        }
+    }
+    impl Yamlify for Match {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { scrutinee, arms } = self;
+            y.key("Match")
+                .pair("scrutinee", scrutinee)
+                .pair("arms", arms);
+        }
+    }
+
+    impl Yamlify for MatchArm {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self(pat, expr) = self;
+            y.pair("pat", pat).pair("expr", expr);
+        }
+    }
     impl Yamlify for Assign {
         fn yaml(&self, y: &mut Yamler) {
             let Self { parts } = self;
@@ -461,6 +510,12 @@ pub mod yamlify {
             y.value(self);
         }
     }
+    impl Yamlify for Cast {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { head, ty } = self;
+            y.key("Cast").pair("head", head).pair("ty", ty);
+        }
+    }
     impl Yamlify for Member {
         fn yaml(&self, y: &mut Yamler) {
             let Self { head, kind } = self;
@@ -516,11 +571,8 @@ pub mod yamlify {
     }
     impl Yamlify for AddrOf {
         fn yaml(&self, y: &mut Yamler) {
-            let Self { count, mutable, expr } = self;
-            y.key("AddrOf")
-                .pair("count", count)
-                .yaml(mutable)
-                .pair("expr", expr);
+            let Self { mutable, expr } = self;
+            y.key("AddrOf").yaml(mutable).pair("expr", expr);
         }
     }
     impl Yamlify for Group {
@@ -529,12 +581,6 @@ pub mod yamlify {
             y.key("Group").yaml(expr);
         }
     }
-    impl Yamlify for Loop {
-        fn yaml(&self, y: &mut Yamler) {
-            let Self { body } = self;
-            y.key("Loop").yaml(body);
-        }
-    }
     impl Yamlify for While {
         fn yaml(&self, y: &mut Yamler) {
             let Self { cond, pass, fail } = self;
@@ -578,11 +624,6 @@ pub mod yamlify {
             y.key("Return").yaml(body);
         }
     }
-    impl Yamlify for Continue {
-        fn yaml(&self, y: &mut Yamler) {
-            y.key("Continue");
-        }
-    }
     impl Yamlify for Literal {
         fn yaml(&self, y: &mut Yamler) {
             y.value(format_args!("\"{self}\""));

compiler/cl-repl/src/args.rs

@@ -35,6 +35,10 @@ argwerk::define! {
     [#[option] path] if file.is_none() => {
         file = path.map(Into::into);
     }
+
+    [path] if file.is_some() => {
+        include.push(path.into());
+    }
 }
 
 /// gets whether stdin AND stdout are a terminal, for pipelining

compiler/cl-repl/src/cli.rs

@@ -5,7 +5,8 @@ use crate::{
     menu,
     tools::print_token,
 };
-use cl_interpret::{convalue::ConValue, env::Environment, interpret::Interpret};
+use cl_ast::File;
+use cl_interpret::{builtin::builtins, convalue::ConValue, env::Environment, interpret::Interpret};
 use cl_lexer::Lexer;
 use cl_parser::Parser;
 use std::{error::Error, path::Path};
@@ -15,6 +16,31 @@ pub fn run(args: Args) -> Result<(), Box<dyn Error>> {
     let Args { file, include, mode, repl } = args;
 
     let mut env = Environment::new();
+
+    env.add_builtins(&builtins! {
+        /// Clears the screen
+        fn clear() {
+            menu::clear();
+            Ok(ConValue::Empty)
+        }
+        /// Evaluates a quoted expression
+        fn eval(ConValue::Quote(quote)) @env {
+            env.eval(quote.as_ref())
+        }
+        /// Executes a file
+        fn import(ConValue::String(path)) @env {
+            load_file(env, &**path).or(Ok(ConValue::Empty))
+        }
+
+        /// Gets a line of input from stdin
+        fn get_line() {
+            match repline::Repline::new("", "", "").read() {
+                Ok(line) => Ok(ConValue::String(line.into())),
+                Err(e) => Ok(ConValue::String(e.to_string().into())),
+            }
+        }
+    });
+
     for path in include {
         load_file(&mut env, path)?;
     }
@@ -49,7 +75,7 @@ fn load_file(env: &mut Environment, path: impl AsRef<Path>) -> Result<ConValue,
     let inliner =
         cl_parser::inliner::ModuleInliner::new(path.as_ref().parent().unwrap_or(Path::new("")));
     let file = std::fs::read_to_string(path)?;
-    let code = Parser::new(Lexer::new(&file)).file()?;
+    let code = Parser::new(Lexer::new(&file)).parse()?;
     let code = match inliner.inline(code) {
         Ok(a) => a,
         Err((code, io_errs, parse_errs)) => {
@@ -79,13 +105,13 @@ fn lex_code(code: &str, path: Option<impl AsRef<Path>>) -> Result<(), Box<dyn Er
 }
 
 fn fmt_code(code: &str) -> Result<(), Box<dyn Error>> {
-    let code = Parser::new(Lexer::new(code)).file()?;
+    let code = Parser::new(Lexer::new(code)).parse::<File>()?;
     println!("{code}");
     Ok(())
 }
 
 fn run_code(code: &str, env: &mut Environment) -> Result<(), Box<dyn Error>> {
-    let code = Parser::new(Lexer::new(code)).file()?;
+    let code = Parser::new(Lexer::new(code)).parse::<File>()?;
     match code.interpret(env)? {
         ConValue::Empty => {}
         ret => println!("{ret}"),

compiler/cl-repl/src/ctx.rs

@@ -1,6 +1,4 @@
-use cl_interpret::{
-    env::Environment, error::IResult, interpret::Interpret, convalue::ConValue,
-};
+use cl_interpret::{convalue::ConValue, env::Environment, error::IResult, interpret::Interpret};
 
 #[derive(Clone, Debug)]
 pub struct Context {

compiler/cl-repl/src/menu.rs

@@ -1,10 +1,12 @@
 use crate::{ansi, ctx};
+use cl_ast::Stmt;
+use cl_interpret::convalue::ConValue;
 use cl_lexer::Lexer;
 use cl_parser::Parser;
 use repline::{error::ReplResult, prebaked::*};
 
-fn clear() {
-    println!("{}", ansi::CLEAR_ALL);
+pub fn clear() {
+    print!("{}", ansi::CLEAR_ALL);
     banner()
 }
 
@@ -42,11 +44,15 @@ pub fn run(ctx: &mut ctx::Context) -> ReplResult<()> {
     use cl_parser::inliner::ModuleInliner;
 
     read_and(ansi::CYAN, "cl>", " ?>", |line| {
-        let code = Parser::new(Lexer::new(line)).stmt()?;
+        if line.trim().is_empty() {
+            return Ok(Response::Deny);
+        }
+        let code = Parser::new(Lexer::new(line)).parse::<Stmt>()?;
         let code = ModuleInliner::new(".").fold_stmt(code);
 
         print!("{}", ansi::OUTPUT);
         match ctx.run(&code) {
+            Ok(ConValue::Empty) => print!("{}", ansi::RESET),
             Ok(v) => println!("{}{v}", ansi::RESET),
             Err(e) => println!("{}! > {e}{}", ansi::RED, ansi::RESET),
         }
@@ -71,7 +77,7 @@ pub fn fmt(_ctx: &mut ctx::Context) -> ReplResult<()> {
     read_and(ansi::BRIGHT_MAGENTA, "cl>", " ?>", |line| {
         let mut p = Parser::new(Lexer::new(line));
 
-        match p.stmt() {
+        match p.parse::<Stmt>() {
             Ok(code) => println!("{}{code}{}", ansi::OUTPUT, ansi::RESET),
             Err(e) => Err(e)?,
         }

compiler/cl-structures/Cargo.toml

@@ -8,4 +8,4 @@ license.workspace = true
 publish.workspace = true
 
 [dependencies]
-cl-arena = { path = "../cl-arena" }
+cl-arena = { version = "0", registry = "soft-fish" }

compiler/cl-structures/src/index_map.rs

@@ -106,7 +106,7 @@ impl<V, K: MapIndex> IndexMap<K, V> {
     pub fn get_many_mut<const N: usize>(
         &mut self,
         indices: [K; N],
-    ) -> Result<[&mut V; N], GetManyMutError<N>> {
+    ) -> Result<[&mut V; N], GetManyMutError> {
         self.map.get_many_mut(indices.map(|id| id.get()))
     }
 

compiler/cl-structures/src/intern.rs

@@ -35,9 +35,14 @@ pub mod interned {
         pub fn as_ptr(interned: &Self) -> *const T {
             interned.value
         }
+
+        /// Gets the internal value as a reference with the interner's lifetime
+        pub fn to_ref(interned: &Self) -> &'a T {
+            interned.value
+        }
     }
 
-    impl<'a, T: ?Sized + Debug> Debug for Interned<'a, T> {
+    impl<T: ?Sized + Debug> Debug for Interned<'_, T> {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             f.debug_struct("Interned")
                 .field("value", &self.value)
@@ -49,14 +54,14 @@ pub mod interned {
             Self { value }
         }
     }
-    impl<'a, T: ?Sized> Deref for Interned<'a, T> {
+    impl<T: ?Sized> Deref for Interned<'_, T> {
         type Target = T;
         fn deref(&self) -> &Self::Target {
             self.value
         }
     }
-    impl<'a, T: ?Sized> Copy for Interned<'a, T> {}
-    impl<'a, T: ?Sized> Clone for Interned<'a, T> {
+    impl<T: ?Sized> Copy for Interned<'_, T> {}
+    impl<T: ?Sized> Clone for Interned<'_, T> {
         fn clone(&self) -> Self {
             *self
         }
@@ -79,13 +84,13 @@ pub mod interned {
     //     }
     // }
 
-    impl<'a, T: ?Sized> Eq for Interned<'a, T> {}
-    impl<'a, T: ?Sized> PartialEq for Interned<'a, T> {
+    impl<T: ?Sized> Eq for Interned<'_, T> {}
+    impl<T: ?Sized> PartialEq for Interned<'_, T> {
         fn eq(&self, other: &Self) -> bool {
             std::ptr::eq(self.value, other.value)
         }
     }
-    impl<'a, T: ?Sized> Hash for Interned<'a, T> {
+    impl<T: ?Sized> Hash for Interned<'_, T> {
         fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
             Self::as_ptr(self).hash(state)
         }
@@ -119,6 +124,7 @@ pub mod string_interner {
     };
 
     /// A string interner hands out [Interned] copies of each unique string given to it.
+    #[derive(Default)]
     pub struct StringInterner<'a> {
         arena: DroplessArena<'a>,
         keys: RwLock<HashSet<&'a str>>,
@@ -185,12 +191,30 @@ pub mod string_interner {
         }
     }
 
+    impl std::fmt::Display for StringInterner<'_> {
+        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+            let Ok(keys) = self.keys.read() else {
+                return write!(f, "Could not lock StringInterner key map.");
+            };
+            let mut keys: Vec<_> = keys.iter().collect();
+            keys.sort();
+
+            writeln!(f, "Keys:")?;
+            for (idx, key) in keys.iter().enumerate() {
+                writeln!(f, "{idx}:\t\"{key}\"")?
+            }
+            writeln!(f, "Count: {}", keys.len())?;
+
+            Ok(())
+        }
+    }
+
     // # Safety:
     // This is fine because StringInterner::get_or_insert(v) holds a RwLock
     // for its entire duration, and doesn't touch the non-(Send+Sync) arena
     // unless the lock is held by a write guard.
-    unsafe impl<'a> Send for StringInterner<'a> {}
-    unsafe impl<'a> Sync for StringInterner<'a> {}
+    unsafe impl Send for StringInterner<'_> {}
+    unsafe impl Sync for StringInterner<'_> {}
 
     #[cfg(test)]
     mod tests {
@@ -240,6 +264,7 @@ pub mod typed_interner {
     /// A [TypedInterner] hands out [Interned] references for arbitrary types.
     ///
     /// See the [module-level documentation](self) for more information.
+    #[derive(Default)]
     pub struct TypedInterner<'a, T: Eq + Hash> {
         arena: TypedArena<'a, T>,
         keys: RwLock<HashSet<&'a T>>,
@@ -286,5 +311,5 @@ pub mod typed_interner {
     /// [get_or_insert](TypedInterner::get_or_insert) are unique, and the function uses
     /// the [RwLock] around the [HashSet] to ensure mutual exclusion
     unsafe impl<'a, T: Eq + Hash + Send> Send for TypedInterner<'a, T> where &'a T: Send {}
-    unsafe impl<'a, T: Eq + Hash + Send + Sync> Sync for TypedInterner<'a, T> {}
+    unsafe impl<T: Eq + Hash + Send + Sync> Sync for TypedInterner<'_, T> {}
 }

compiler/cl-token/src/lib.rs

@@ -10,4 +10,4 @@ pub mod token_type;
 
 pub use token::Token;
 pub use token_data::TokenData;
-pub use token_type::{Punct, TokenKind};
+pub use token_type::TokenKind;

compiler/cl-token/src/token_type.rs

@@ -13,41 +13,36 @@ pub enum TokenKind {
     /// A non-keyword identifier
     Identifier,
     // A keyword
-    As,
-    Break,
-    Cl,
-    Const,
-    Continue,
-    Else,
-    Enum,
-    False,
-    For,
-    Fn,
-    If,
-    Impl,
-    In,
-    Let,
-    Loop,
-    Mod,
-    Mut,
-    Pub,
-    Return,
-    SelfKw,
-    SelfTy,
-    Static,
-    Struct,
-    Super,
-    True,
-    Type,
-    Use,
-    While,
-    /// Delimiter or punctuation
-    Punct(Punct),
-}
-
-/// An operator character (delimiter, punctuation)
-#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
-pub enum Punct {
+    As,       // as
+    Break,    // "break"
+    Cl,       // "cl"
+    Const,    // "const"
+    Continue, // "continue"
+    Else,     // "else"
+    Enum,     // "enum"
+    False,    // "false"
+    Fn,       // "fn"
+    For,      // "for"
+    If,       // "if"
+    Impl,     // "impl"
+    In,       // "in"
+    Let,      // "let"
+    Loop,     // "loop"
+    Match,    // "match"
+    Mod,      // "mod"
+    Mut,      // "mut"
+    Pub,      // "pub"
+    Return,   // "return"
+    SelfKw,   // "self"
+    SelfTy,   // "Self"
+    Static,   // "static"
+    Struct,   // "struct"
+    Super,    // "super"
+    True,     // "true"
+    Type,     // "type"
+    Use,      // "use"
+    While,    // "while"
+    // Delimiter or punctuation
     LCurly,     // {
     RCurly,     // }
     LBrack,     // [
@@ -112,36 +107,90 @@ impl Display for TokenKind {
             TokenKind::Literal => "literal".fmt(f),
             TokenKind::Identifier => "identifier".fmt(f),
 
-            TokenKind::As => "as".fmt(f),
-            TokenKind::Break => "break".fmt(f),
-            TokenKind::Cl => "cl".fmt(f),
-            TokenKind::Const => "const".fmt(f),
-            TokenKind::Continue => "continue".fmt(f),
-            TokenKind::Else => "else".fmt(f),
-            TokenKind::Enum => "enum".fmt(f),
-            TokenKind::False => "false".fmt(f),
-            TokenKind::For => "for".fmt(f),
-            TokenKind::Fn => "fn".fmt(f),
-            TokenKind::If => "if".fmt(f),
-            TokenKind::Impl => "impl".fmt(f),
-            TokenKind::In => "in".fmt(f),
-            TokenKind::Let => "let".fmt(f),
-            TokenKind::Loop => "loop".fmt(f),
-            TokenKind::Mod => "mod".fmt(f),
-            TokenKind::Mut => "mut".fmt(f),
-            TokenKind::Pub => "pub".fmt(f),
-            TokenKind::Return => "return".fmt(f),
-            TokenKind::SelfKw => "self".fmt(f),
-            TokenKind::SelfTy => "Self".fmt(f),
-            TokenKind::Static => "static".fmt(f),
-            TokenKind::Struct => "struct".fmt(f),
-            TokenKind::Super => "super".fmt(f),
-            TokenKind::True => "true".fmt(f),
-            TokenKind::Type => "type".fmt(f),
-            TokenKind::Use => "use".fmt(f),
-            TokenKind::While => "while".fmt(f),
+            TokenKind::As => "sama".fmt(f),
+            TokenKind::Break => "pana".fmt(f),
+            TokenKind::Cl => "la".fmt(f),
+            TokenKind::Const => "kiwen".fmt(f),
+            TokenKind::Continue => "tawa".fmt(f),
+            TokenKind::Else => "taso".fmt(f),
+            TokenKind::Enum => "kulupu".fmt(f),
+            TokenKind::False => "ike".fmt(f),
+            TokenKind::Fn => "nasin".fmt(f),
+            TokenKind::For => "ale".fmt(f),
+            TokenKind::If => "tan".fmt(f),
+            TokenKind::Impl => "insa".fmt(f),
+            TokenKind::In => "lon".fmt(f),
+            TokenKind::Let => "poki".fmt(f),
+            TokenKind::Loop => "awen".fmt(f),
+            TokenKind::Match => "seme".fmt(f),
+            TokenKind::Mod => "selo".fmt(f),
+            TokenKind::Mut => "ante".fmt(f),
+            TokenKind::Pub => "lukin".fmt(f),
+            TokenKind::Return => "pini".fmt(f),
+            TokenKind::SelfKw => "mi".fmt(f),
+            TokenKind::SelfTy => "Mi".fmt(f),
+            TokenKind::Static => "mute".fmt(f),
+            TokenKind::Struct => "lipu".fmt(f),
+            TokenKind::Super => "mama".fmt(f),
+            TokenKind::True => "pona".fmt(f),
+            TokenKind::Type => "ijo".fmt(f),
+            TokenKind::Use => "jo".fmt(f),
+            TokenKind::While => "lawa".fmt(f),
 
-            TokenKind::Punct(op) => op.fmt(f),
+            TokenKind::LCurly => "{".fmt(f),
+            TokenKind::RCurly => "}".fmt(f),
+            TokenKind::LBrack => "[".fmt(f),
+            TokenKind::RBrack => "]".fmt(f),
+            TokenKind::LParen => "(".fmt(f),
+            TokenKind::RParen => ")".fmt(f),
+            TokenKind::Amp => "&".fmt(f),
+            TokenKind::AmpAmp => "&&".fmt(f),
+            TokenKind::AmpEq => "&=".fmt(f),
+            TokenKind::Arrow => "->".fmt(f),
+            TokenKind::At => "@".fmt(f),
+            TokenKind::Backslash => "\\".fmt(f),
+            TokenKind::Bang => "!".fmt(f),
+            TokenKind::BangBang => "!!".fmt(f),
+            TokenKind::BangEq => "!=".fmt(f),
+            TokenKind::Bar => "|".fmt(f),
+            TokenKind::BarBar => "||".fmt(f),
+            TokenKind::BarEq => "|=".fmt(f),
+            TokenKind::Colon => ":".fmt(f),
+            TokenKind::ColonColon => "::".fmt(f),
+            TokenKind::Comma => ",".fmt(f),
+            TokenKind::Dot => ".".fmt(f),
+            TokenKind::DotDot => "..".fmt(f),
+            TokenKind::DotDotEq => "..=".fmt(f),
+            TokenKind::Eq => "=".fmt(f),
+            TokenKind::EqEq => "==".fmt(f),
+            TokenKind::FatArrow => "=>".fmt(f),
+            TokenKind::Grave => "`".fmt(f),
+            TokenKind::Gt => ">".fmt(f),
+            TokenKind::GtEq => ">=".fmt(f),
+            TokenKind::GtGt => ">>".fmt(f),
+            TokenKind::GtGtEq => ">>=".fmt(f),
+            TokenKind::Hash => "#".fmt(f),
+            TokenKind::HashBang => "#!".fmt(f),
+            TokenKind::Lt => "<".fmt(f),
+            TokenKind::LtEq => "<=".fmt(f),
+            TokenKind::LtLt => "<<".fmt(f),
+            TokenKind::LtLtEq => "<<=".fmt(f),
+            TokenKind::Minus => "-".fmt(f),
+            TokenKind::MinusEq => "-=".fmt(f),
+            TokenKind::Plus => "+".fmt(f),
+            TokenKind::PlusEq => "+=".fmt(f),
+            TokenKind::Question => "?".fmt(f),
+            TokenKind::Rem => "%".fmt(f),
+            TokenKind::RemEq => "%=".fmt(f),
+            TokenKind::Semi => ";".fmt(f),
+            TokenKind::Slash => "/".fmt(f),
+            TokenKind::SlashEq => "/=".fmt(f),
+            TokenKind::Star => "*".fmt(f),
+            TokenKind::StarEq => "*=".fmt(f),
+            TokenKind::Tilde => "~".fmt(f),
+            TokenKind::Xor => "^".fmt(f),
+            TokenKind::XorEq => "^=".fmt(f),
+            TokenKind::XorXor => "^^".fmt(f),
         }
     }
 }
@@ -151,96 +200,36 @@ impl FromStr for TokenKind {
     /// Parses a string s to return a Keyword
     fn from_str(s: &str) -> Result<Self, Self::Err> {
         Ok(match s {
-            "as" => Self::As,
-            "break" => Self::Break,
-            "cl" => Self::Cl,
-            "const" => Self::Const,
-            "continue" => Self::Continue,
-            "else" => Self::Else,
-            "enum" => Self::Enum,
-            "false" => Self::False,
-            "for" => Self::For,
-            "fn" => Self::Fn,
-            "if" => Self::If,
-            "impl" => Self::Impl,
-            "in" => Self::In,
-            "let" => Self::Let,
-            "loop" => Self::Loop,
-            "mod" => Self::Mod,
-            "mut" => Self::Mut,
-            "pub" => Self::Pub,
-            "return" => Self::Return,
-            "self" => Self::SelfKw,
-            "Self" => Self::SelfTy,
-            "static" => Self::Static,
-            "struct" => Self::Struct,
-            "super" => Self::Super,
-            "true" => Self::True,
-            "type" => Self::Type,
-            "use" => Self::Use,
-            "while" => Self::While,
+            "as" | "sama" => Self::As,
+            "break" | "pana" => Self::Break,
+            "cl" | "la" => Self::Cl,
+            "const" | "kiwen" => Self::Const,
+            "continue" | "tawa" => Self::Continue,
+            "else" | "taso" => Self::Else,
+            "enum" | "kulupu" => Self::Enum,
+            "false" | "ike" => Self::False,
+            "fn" | "nasin" => Self::Fn,
+            "for" | "ale" => Self::For,
+            "if" | "tan" => Self::If,
+            "impl" | "insa" => Self::Impl,
+            "in" | "lon" => Self::In,
+            "let" | "poki" => Self::Let,
+            "loop" | "awen" => Self::Loop,
+            "match" | "seme" => Self::Match,
+            "mod" | "selo" => Self::Mod,
+            "mut" | "ante" => Self::Mut,
+            "pub" | "lukin" => Self::Pub,
+            "return" | "pini" => Self::Return,
+            "self" | "mi" => Self::SelfKw,
+            "Self" | "Mi" => Self::SelfTy,
+            "static" | "mute" => Self::Static,
+            "struct" | "lipu" => Self::Struct,
+            "super" | "mama" => Self::Super,
+            "true" | "pona" => Self::True,
+            "type" | "ijo" => Self::Type,
+            "use" | "jo" => Self::Use,
+            "while" | "lawa" => Self::While,
             _ => Err(())?,
         })
     }
 }
-
-impl Display for Punct {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        match self {
-            Punct::LCurly => "{".fmt(f),
-            Punct::RCurly => "}".fmt(f),
-            Punct::LBrack => "[".fmt(f),
-            Punct::RBrack => "]".fmt(f),
-            Punct::LParen => "(".fmt(f),
-            Punct::RParen => ")".fmt(f),
-            Punct::Amp => "&".fmt(f),
-            Punct::AmpAmp => "&&".fmt(f),
-            Punct::AmpEq => "&=".fmt(f),
-            Punct::Arrow => "->".fmt(f),
-            Punct::At => "@".fmt(f),
-            Punct::Backslash => "\\".fmt(f),
-            Punct::Bang => "!".fmt(f),
-            Punct::BangBang => "!!".fmt(f),
-            Punct::BangEq => "!=".fmt(f),
-            Punct::Bar => "|".fmt(f),
-            Punct::BarBar => "||".fmt(f),
-            Punct::BarEq => "|=".fmt(f),
-            Punct::Colon => ":".fmt(f),
-            Punct::ColonColon => "::".fmt(f),
-            Punct::Comma => ",".fmt(f),
-            Punct::Dot => ".".fmt(f),
-            Punct::DotDot => "..".fmt(f),
-            Punct::DotDotEq => "..=".fmt(f),
-            Punct::Eq => "=".fmt(f),
-            Punct::EqEq => "==".fmt(f),
-            Punct::FatArrow => "=>".fmt(f),
-            Punct::Grave => "`".fmt(f),
-            Punct::Gt => ">".fmt(f),
-            Punct::GtEq => ">=".fmt(f),
-            Punct::GtGt => ">>".fmt(f),
-            Punct::GtGtEq => ">>=".fmt(f),
-            Punct::Hash => "#".fmt(f),
-            Punct::HashBang => "#!".fmt(f),
-            Punct::Lt => "<".fmt(f),
-            Punct::LtEq => "<=".fmt(f),
-            Punct::LtLt => "<<".fmt(f),
-            Punct::LtLtEq => "<<=".fmt(f),
-            Punct::Minus => "-".fmt(f),
-            Punct::MinusEq => "-=".fmt(f),
-            Punct::Plus => "+".fmt(f),
-            Punct::PlusEq => "+=".fmt(f),
-            Punct::Question => "?".fmt(f),
-            Punct::Rem => "%".fmt(f),
-            Punct::RemEq => "%=".fmt(f),
-            Punct::Semi => ";".fmt(f),
-            Punct::Slash => "/".fmt(f),
-            Punct::SlashEq => "/=".fmt(f),
-            Punct::Star => "*".fmt(f),
-            Punct::StarEq => "*=".fmt(f),
-            Punct::Tilde => "~".fmt(f),
-            Punct::Xor => "^".fmt(f),
-            Punct::XorEq => "^=".fmt(f),
-            Punct::XorXor => "^^".fmt(f),
-        }
-    }
-}

compiler/cl-typeck/examples/typeck.rs

@@ -1,76 +1,80 @@
+use cl_typeck::{entry::Entry, stage::*, table::Table, type_expression::TypeExpression};
+
 use cl_ast::{
     ast_visitor::{Fold, Visit},
     desugar::*,
+    Stmt, Ty,
 };
 use cl_lexer::Lexer;
 use cl_parser::{inliner::ModuleInliner, Parser};
-use cl_typeck::{
-    definition::Def,
-    handle::Handle,
-    name_collector::NameCollector,
-    node::{Node, NodeSource},
-    project::Project,
-    type_resolver::resolve,
-};
+use cl_structures::intern::string_interner::StringInterner;
 use repline::{error::Error as RlError, prebaked::*};
-use std::{error::Error, path};
+use std::{
+    error::Error,
+    path::{self, PathBuf},
+    sync::LazyLock,
+};
 
 // Path to display in standard library errors
 const STDLIB_DISPLAY_PATH: &str = "stdlib/lib.cl";
 // Statically included standard library
-const STDLIB: &str = include_str!("../../../stdlib/lib.cl");
+const PREAMBLE: &str = r"
+pub mod std;
+pub use std::preamble::*;
+";
 
 // Colors
-const C_MAIN: &str = "";
+const C_MAIN: &str = C_LISTING;
 const C_RESV: &str = "\x1b[35m";
 const C_CODE: &str = "\x1b[36m";
 const C_BYID: &str = "\x1b[95m";
+const C_ERROR: &str = "\x1b[31m";
 const C_LISTING: &str = "\x1b[38;5;117m";
 
-/// A home for immutable intermediate ASTs
-///
-/// TODO: remove this.
-static mut TREES: TreeManager = TreeManager::new();
-
 fn main() -> Result<(), Box<dyn Error>> {
-    let mut prj = Project::default();
+    let mut prj = Table::default();
 
-    let mut parser = Parser::new(Lexer::new(STDLIB));
-    let code = match parser.file() {
+    let mut parser = Parser::new(Lexer::new(PREAMBLE));
+    let code = match parser.parse() {
         Ok(code) => code,
         Err(e) => {
             eprintln!("{STDLIB_DISPLAY_PATH}:{e}");
             Err(e)?
         }
     };
-    let code = inline_modules(code, concat!(env!("PWD"), "/stdlib"));
-    NameCollector::new(&mut prj).visit_file(unsafe { TREES.push(code) });
+    // This code is special - it gets loaded from a hard-coded project directory (for now)
+    let code = inline_modules(code, concat!(env!("CARGO_MANIFEST_DIR"), "/../../stdlib"));
+    Populator::new(&mut prj).visit_file(interned(code));
 
     main_menu(&mut prj)?;
     Ok(())
 }
 
-fn main_menu(prj: &mut Project) -> Result<(), RlError> {
+fn main_menu(prj: &mut Table) -> Result<(), RlError> {
     banner();
     read_and(C_MAIN, "mu>", "? >", |line| {
         match line.trim() {
             "c" | "code" => enter_code(prj)?,
             "clear" => clear()?,
+            "d" | "desugar" => live_desugar()?,
             "e" | "exit" => return Ok(Response::Break),
+            "f" | "file" => import_files(prj)?,
+            "i" | "id" => get_by_id(prj)?,
             "l" | "list" => list_types(prj),
             "q" | "query" => query_type_expression(prj)?,
-            "i" | "id" => get_by_id(prj)?,
             "r" | "resolve" => resolve_all(prj)?,
-            "d" | "desugar" => live_desugar()?,
-            "h" | "help" => {
+            "s" | "strings" => print_strings(),
+            "h" | "help" | "" => {
                 println!(
                     "Valid commands are:
+    clear      : Clear the screen
     code    (c): Enter code to type-check
+    desugar (d): WIP: Test the experimental desugaring passes
+    file    (f): Load files from disk
+    id      (i): Get a type by its type ID
     list    (l): List all known types
     query   (q): Query the type system
-    id      (i): Get a type by its type ID
     resolve (r): Perform type resolution
-    desugar (d): WIP: Test the experimental desugaring passes
     help    (h): Print this list
     exit    (e): Exit the program"
                 );
@@ -82,24 +86,23 @@ fn main_menu(prj: &mut Project) -> Result<(), RlError> {
     })
 }
 
-fn enter_code(prj: &mut Project) -> Result<(), RlError> {
+fn enter_code(prj: &mut Table) -> Result<(), RlError> {
     read_and(C_CODE, "cl>", "? >", |line| {
         if line.trim().is_empty() {
             return Ok(Response::Break);
         }
-        let code = Parser::new(Lexer::new(line)).file()?;
+        let code = Parser::new(Lexer::new(line)).parse()?;
         let code = inline_modules(code, "");
         let code = WhileElseDesugar.fold_file(code);
-        // Safety: this is totally unsafe
-        NameCollector::new(prj).visit_file(unsafe { TREES.push(code) });
 
+        Populator::new(prj).visit_file(interned(code));
         Ok(Response::Accept)
     })
 }
 
 fn live_desugar() -> Result<(), RlError> {
     read_and(C_RESV, "se>", "? >", |line| {
-        let code = Parser::new(Lexer::new(line)).stmt()?;
+        let code = Parser::new(Lexer::new(line)).parse::<Stmt>()?;
         println!("Raw, as parsed:\n{C_LISTING}{code}\x1b[0m");
 
         let code = SquashGroups.fold_stmt(code);
@@ -115,37 +118,40 @@ fn live_desugar() -> Result<(), RlError> {
     })
 }
 
-fn query_type_expression(prj: &mut Project) -> Result<(), RlError> {
+fn print_strings() {
+    println!("{}", StringInterner::global());
+}
+
+fn query_type_expression(prj: &mut Table) -> Result<(), RlError> {
     read_and(C_RESV, "ty>", "? >", |line| {
         if line.trim().is_empty() {
             return Ok(Response::Break);
         }
         // parse it as a path, and convert the path into a borrowed path
-        let ty = Parser::new(Lexer::new(line)).ty()?.kind;
-        let id = prj.evaluate(&ty, prj.root)?.handle_unchecked(prj);
-        pretty_handle(id)?;
+        let ty: Ty = Parser::new(Lexer::new(line)).parse()?;
+        let id = ty.evaluate(prj, prj.root())?;
+        pretty_handle(id.to_entry(prj))?;
         Ok(Response::Accept)
     })
 }
 
-fn get_by_id(prj: &mut Project) -> Result<(), RlError> {
+fn get_by_id(prj: &mut Table) -> Result<(), RlError> {
+    use cl_parser::parser::Parse;
     use cl_structures::index_map::MapIndex;
-    use cl_typeck::handle::DefID;
+    use cl_typeck::handle::Handle;
     read_and(C_BYID, "id>", "? >", |line| {
         if line.trim().is_empty() {
             return Ok(Response::Break);
         }
         let mut parser = Parser::new(Lexer::new(line));
-        let def_id = match parser.literal()? {
+        let def_id = match Parse::parse(&mut parser)? {
             cl_ast::Literal::Int(int) => int as _,
             other => Err(format!("Expected integer, got {other}"))?,
         };
-        let mut path = parser.path().unwrap_or_default();
+        let mut path = parser.parse::<cl_ast::Path>().unwrap_or_default();
         path.absolute = false;
 
-        let Some(handle) = DefID::from_usize(def_id).handle(prj) else {
-            return Ok(Response::Deny);
-        };
+        let handle = Handle::from_usize(def_id).to_entry(prj);
 
         print!("  > {{{C_LISTING}{handle}\x1b[0m}}");
         if !path.parts.is_empty() {
@@ -153,71 +159,134 @@ fn get_by_id(prj: &mut Project) -> Result<(), RlError> {
         }
         println!();
 
-        let (ty, value) = handle.navigate((&path).into());
-        if let (None, None) = (ty, value) {
+        let Some(entry) = handle.nav(&path.parts) else {
             Err("No results.")?
-        }
-        if let Some(t) = ty {
-            println!("Result in type namespace: {}", t.id());
-            pretty_handle(t)?;
-        }
-        if let Some(v) = value {
-            println!("Result in value namespace: {}", v.id());
-            pretty_handle(v)?;
-        }
+        };
+
+        pretty_handle(entry)?;
 
         Ok(Response::Accept)
     })
 }
 
-fn resolve_all(prj: &mut Project) -> Result<(), Box<dyn Error>> {
-    prj.resolve_imports()?;
-    for id in prj.pool.keys() {
-        resolve(prj, id)?;
+fn resolve_all(table: &mut Table) -> Result<(), Box<dyn Error>> {
+    for (id, error) in import(table) {
+        eprintln!("{error} in {} ({id})", id.to_entry(table))
     }
-    println!("Types resolved successfully!");
+    for handle in table.handle_iter() {
+        if let Err(error) = handle.to_entry_mut(table).categorize() {
+            eprintln!("{error}");
+        }
+    }
+
+    for handle in implement(table) {
+        eprintln!("Unable to reparent {} ({handle})", handle.to_entry(table))
+    }
+
+    println!("...Resolved!");
     Ok(())
 }
 
-fn list_types(prj: &mut Project) {
-    println!("     name\x1b[30G  type");
-    for (idx, key) in prj.pool.keys().enumerate() {
-        let Def { node: Node { vis, kind: source, .. }, .. } = &prj[key];
-        let name = match source.as_ref().map(NodeSource::name) {
-            Some(Some(name)) => name,
-            _ => "".into(),
-        };
-        print!(
-            "{idx:3}: {vis}{name}\x1b[30G = {}",
-            key.handle_unchecked(prj)
-        );
-        println!();
+fn list_types(table: &mut Table) {
+    for handle in table.debug_entry_iter() {
+        let id = handle.id();
+        let kind = handle.kind().unwrap();
+        let name = handle.name().unwrap_or("".into());
+        println!("{id:3}: {name:16}| {kind}: {handle}");
     }
 }
 
-fn pretty_handle(handle: Handle) -> Result<(), std::io::Error> {
+fn import_files(table: &mut Table) -> Result<(), RlError> {
+    read_and(C_RESV, "fi>", "? >", |line| {
+        let line = line.trim();
+        if line.is_empty() {
+            return Ok(Response::Break);
+        }
+        let Ok(file) = std::fs::read_to_string(line) else {
+            for file in std::fs::read_dir(line)? {
+                println!("{}", file?.path().display())
+            }
+            return Ok(Response::Accept);
+        };
+
+        let mut parser = Parser::new(Lexer::new(&file));
+        let code = match parser.parse() {
+            Ok(code) => inline_modules(code, PathBuf::from(line).parent().unwrap_or("".as_ref())),
+            Err(e) => {
+                eprintln!("{C_ERROR}{line}:{e}\x1b[0m");
+                return Ok(Response::Deny);
+            }
+        };
+
+        Populator::new(table).visit_file(interned(code));
+
+        println!("...Imported!");
+        Ok(Response::Accept)
+    })
+}
+
+fn pretty_handle(entry: Entry) -> Result<(), std::io::Error> {
     use std::io::Write;
-    let mut stdout = std::io::stdout().lock();
-    let Some(Def { module, node: Node { vis, .. }, .. }) = handle.get() else {
-        return writeln!(stdout, "Invalid handle: {handle}");
+    let mut out = std::io::stdout().lock();
+    let Some(kind) = entry.kind() else {
+        return writeln!(out, "{entry}");
     };
-    writeln!(stdout, "{C_LISTING}{vis}{handle}\x1b[0m: {}", handle.id())?;
-    if let Some(parent) = module.parent {
-        writeln!(stdout, "{C_LISTING}Parent\x1b[0m: {}", handle.with(parent))?;
+    write!(out, "{C_LISTING}{kind}")?;
+
+    if let Some(name) = entry.name() {
+        write!(out, " {name}")?;
     }
-    if !module.types.is_empty() {
-        writeln!(stdout, "{C_LISTING}Types:\x1b[0m")?;
-        for (name, def) in &module.types {
-            writeln!(stdout, "- {C_LISTING}{name}\x1b[0m: {}", handle.with(*def))?
+    writeln!(out, "\x1b[0m ({}): {entry}", entry.id())?;
+
+    if let Some(parent) = entry.parent() {
+        writeln!(
+            out,
+            "- {C_LISTING}Parent\x1b[0m: {parent} ({})",
+            parent.id()
+        )?;
+    }
+
+    if let Some(span) = entry.span() {
+        writeln!(
+            out,
+            "- {C_LISTING}Span:\x1b[0m ({}, {})",
+            span.head, span.tail
+        )?;
+    }
+
+    match entry.meta() {
+        Some(meta) if !meta.is_empty() => {
+            writeln!(out, "- {C_LISTING}Meta:\x1b[0m")?;
+            for meta in meta {
+                writeln!(out, "  - {meta}")?;
+            }
+        }
+        _ => {}
+    }
+
+    if let Some(children) = entry.children() {
+        writeln!(out, "- {C_LISTING}Children:\x1b[0m")?;
+        for (name, child) in children {
+            writeln!(
+                out,
+                "  - {C_LISTING}{name}\x1b[0m ({child}): {}",
+                entry.with_id(*child)
+            )?
         }
     }
-    if !module.values.is_empty() {
-        writeln!(stdout, "{C_LISTING}Values:\x1b[0m")?;
-        for (name, def) in &module.values {
-            writeln!(stdout, "- {C_LISTING}{name}\x1b[0m: {}", handle.with(*def))?
+
+    if let Some(imports) = entry.imports() {
+        writeln!(out, "- {C_LISTING}Imports:\x1b[0m")?;
+        for (name, child) in imports {
+            writeln!(
+                out,
+                "  - {C_LISTING}{name}\x1b[0m ({child}): {}",
+                entry.with_id(*child)
+            )?
         }
     }
-    write!(stdout, "\x1b[0m")
+
+    Ok(())
 }
 
 fn inline_modules(code: cl_ast::File, path: impl AsRef<path::Path>) -> cl_ast::File {
@@ -249,18 +318,11 @@ fn banner() {
     );
 }
 
-/// Keeps leaked references to past ASTs, for posterity:tm:
-struct TreeManager {
-    trees: Vec<&'static cl_ast::File>,
-}
+/// Interns a [File](cl_ast::File), returning a static reference to it.
+fn interned(file: cl_ast::File) -> &'static cl_ast::File {
+    use cl_structures::intern::{interned::Interned, typed_interner::TypedInterner};
+    static INTERNER: LazyLock<TypedInterner<'static, cl_ast::File>> =
+        LazyLock::new(Default::default);
 
-impl TreeManager {
-    const fn new() -> Self {
-        Self { trees: vec![] }
-    }
-    fn push(&mut self, tree: cl_ast::File) -> &'static cl_ast::File {
-        let ptr = Box::leak(Box::new(tree));
-        self.trees.push(ptr);
-        ptr
-    }
+    Interned::to_ref(&INTERNER.get_or_insert(file))
 }

compiler/cl-typeck/src/definition.rs

@@ -1,193 +0,0 @@
-use crate::{
-    handle::DefID,
-    module::Module,
-    node::{Node, NodeSource},
-};
-use cl_ast::{Meta, Sym, Visibility};
-use std::{fmt::Debug, str::FromStr};
-
-mod display;
-
-#[derive(Clone, Debug, PartialEq, Eq)]
-pub struct Def<'a> {
-    pub node: Node<'a>,
-    pub kind: DefKind,
-    pub module: Module,
-}
-
-impl<'a> Def<'a> {
-    pub fn with_node(node: Node<'a>) -> Self {
-        Self { node, kind: DefKind::Undecided, module: Default::default() }
-    }
-}
-
-impl Def<'_> {
-    pub fn name(&self) -> Option<Sym> {
-        match self.node.kind {
-            Some(source) => source.name(),
-            None => None,
-        }
-    }
-
-    pub fn is_transparent(&self) -> bool {
-        !matches!(self.kind, DefKind::Type(_))
-    }
-}
-
-mod builder_functions {
-    use super::*;
-
-    impl<'a> Def<'a> {
-        pub fn set_vis(&mut self, vis: Visibility) -> &mut Self {
-            self.node.vis = vis;
-            self
-        }
-        pub fn set_meta(&mut self, meta: &'a [Meta]) -> &mut Self {
-            self.node.meta = meta;
-            self
-        }
-        pub fn set_kind(&mut self, kind: DefKind) -> &mut Self {
-            self.kind = kind;
-            self
-        }
-        pub fn set_source(&mut self, source: NodeSource<'a>) -> &mut Self {
-            self.node.kind = Some(source);
-            self
-        }
-        pub fn set_module(&mut self, module: Module) -> &mut Self {
-            self.module = module;
-            self
-        }
-    }
-}
-
-#[derive(Clone, Default, Debug, PartialEq, Eq)]
-pub enum DefKind {
-    /// An unevaluated definition
-    #[default]
-    Undecided,
-    /// An impl block
-    Impl(DefID),
-    /// A use tree, and its parent
-    Use(DefID),
-    /// A type, such as a `type`, `struct`, or `enum`
-    Type(TypeKind),
-    /// A value, such as a `const`, `static`, or `fn`
-    Value(ValueKind),
-}
-
-/// A [ValueKind] represents an item in the Value Namespace
-/// (a component of a [Project](crate::project::Project)).
-#[derive(Clone, Debug, PartialEq, Eq)]
-pub enum ValueKind {
-    Const(DefID),
-    Static(DefID),
-    Local(DefID),
-    Fn(DefID),
-}
-/// A [TypeKind] represents an item in the Type Namespace
-/// (a component of a [Project](crate::project::Project)).
-#[derive(Clone, Debug, PartialEq, Eq, Hash)]
-pub enum TypeKind {
-    /// An alias for an already-defined type
-    Alias(Option<DefID>),
-    /// A primitive type, built-in to the compiler
-    Intrinsic(Intrinsic),
-    /// A user-defined aromatic data type
-    Adt(Adt),
-    /// A reference to an already-defined type: &T
-    Ref(u16, DefID),
-    /// A contiguous view of dynamically sized memory
-    Slice(DefID),
-    /// A contiguous view of statically sized memory
-    Array(DefID, usize),
-    /// A tuple of existing types
-    Tuple(Vec<DefID>),
-    /// A function which accepts multiple inputs and produces an output
-    FnSig { args: DefID, rety: DefID },
-    /// The unit type
-    Empty,
-    /// The never type
-    Never,
-    /// An untyped module
-    Module,
-}
-
-/// A user-defined Aromatic Data Type
-#[derive(Clone, Debug, PartialEq, Eq, Hash)]
-pub enum Adt {
-    /// A union-like enum type
-    Enum(Vec<(Sym, Option<DefID>)>),
-    /// A C-like enum
-    CLikeEnum(Vec<(Sym, u128)>),
-    /// An enum with no fields, which can never be constructed
-    FieldlessEnum,
-
-    /// A structural product type with named members
-    Struct(Vec<(Sym, Visibility, DefID)>),
-    /// A structural product type with unnamed members
-    TupleStruct(Vec<(Visibility, DefID)>),
-    /// A structural product type of neither named nor unnamed members
-    UnitStruct,
-
-    /// A choose your own undefined behavior type
-    /// TODO: should unions be a language feature?
-    Union(Vec<(Sym, DefID)>),
-}
-
-/// The set of compiler-intrinsic types.
-/// These primitive types have native implementations of the basic operations.
-#[allow(non_camel_case_types)]
-#[derive(Clone, Debug, PartialEq, Eq, Hash)]
-pub enum Intrinsic {
-    /// An 8-bit signed integer: `#[intrinsic = "i8"]`
-    I8,
-    /// A 16-bit signed integer: `#[intrinsic = "i16"]`
-    I16,
-    /// A 32-bit signed integer: `#[intrinsic = "i32"]`
-    I32,
-    /// A 64-bit signed integer: `#[intrinsic = "i32"]`
-    I64,
-    // /// A 128-bit signed integer: `#[intrinsic = "i32"]`
-    // I128,
-    /// A ptr-len signed integer: `#[intrinsic = "isize"]`
-    Isize,
-    /// An 8-bit unsigned integer: `#[intrinsic = "u8"]`
-    U8,
-    /// A 16-bit unsigned integer: `#[intrinsic = "u16"]`
-    U16,
-    /// A 32-bit unsigned integer: `#[intrinsic = "u32"]`
-    U32,
-    /// A 64-bit unsigned integer: `#[intrinsic = "u64"]`
-    U64,
-    // /// A 128-bit unsigned integer: `#[intrinsic = "u128"]`
-    // U128,
-    /// A ptr-len unsigned integer: `#[intrinsic = "isize"]`
-    Usize,
-    /// A boolean (`true` or `false`): `#[intrinsic = "bool"]`
-    Bool,
-    /// The unicode codepoint type: #[intrinsic = "char"]
-    Char,
-}
-
-impl FromStr for Intrinsic {
-    type Err = ();
-
-    fn from_str(s: &str) -> Result<Self, Self::Err> {
-        Ok(match s {
-            "i8" => Intrinsic::I8,
-            "i16" => Intrinsic::I16,
-            "i32" => Intrinsic::I32,
-            "i64" => Intrinsic::I64,
-            "isize" => Intrinsic::Isize,
-            "u8" => Intrinsic::U8,
-            "u16" => Intrinsic::U16,
-            "u32" => Intrinsic::U32,
-            "u64" => Intrinsic::U64,
-            "usize" => Intrinsic::Usize,
-            "bool" => Intrinsic::Bool,
-            "char" => Intrinsic::Char,
-            _ => Err(())?,
-        })
-    }
-}

compiler/cl-typeck/src/entry.rs

@@ -0,0 +1,184 @@
+//! An [Entry] is an accessor for [nodes](Handle) in a [Table].
+//!
+//! There are two kinds of entry:
+//! - [Entry]: Provides getters for an entry's fields, and an implementation of
+//!   [Display](std::fmt::Display)
+//! - [EntryMut]: Provides setters for an entry's fields, and an [`as_ref`](EntryMut::as_ref) method
+//!   to demote to an [Entry].
+
+use std::collections::HashMap;
+
+use cl_ast::{Meta, PathPart, Sym};
+use cl_structures::span::Span;
+
+use crate::{
+    handle::Handle,
+    source::Source,
+    stage::categorize as cat,
+    table::{NodeKind, Table},
+    type_expression::{self as tex, TypeExpression},
+    type_kind::TypeKind,
+};
+
+mod display;
+
+impl Handle {
+    pub const fn to_entry<'t, 'a>(self, table: &'t Table<'a>) -> Entry<'t, 'a> {
+        Entry { id: self, table }
+    }
+    pub fn to_entry_mut<'t, 'a>(self, table: &'t mut Table<'a>) -> EntryMut<'t, 'a> {
+        EntryMut { id: self, table }
+    }
+}
+
+#[derive(Debug)]
+pub struct Entry<'t, 'a> {
+    table: &'t Table<'a>,
+    id: Handle,
+}
+
+impl<'t, 'a> Entry<'t, 'a> {
+    pub const fn new(table: &'t Table<'a>, id: Handle) -> Self {
+        Self { table, id }
+    }
+
+    pub const fn id(&self) -> Handle {
+        self.id
+    }
+
+    pub fn inner(&self) -> &Table<'a> {
+        self.table
+    }
+
+    pub const fn with_id(&self, id: Handle) -> Entry<'_, 'a> {
+        Self { table: self.table, id }
+    }
+
+    pub fn nav(&self, path: &[PathPart]) -> Option<Entry<'_, 'a>> {
+        Some(Entry { id: self.table.nav(self.id, path)?, table: self.table })
+    }
+
+    pub const fn root(&self) -> Handle {
+        self.table.root()
+    }
+
+    pub fn kind(&self) -> Option<&NodeKind> {
+        self.table.kind(self.id)
+    }
+
+    pub fn parent(&self) -> Option<Entry<'_, 'a>> {
+        Some(Entry { id: *self.table.parent(self.id)?, ..*self })
+    }
+
+    pub fn children(&self) -> Option<&HashMap<Sym, Handle>> {
+        self.table.children(self.id)
+    }
+
+    pub fn imports(&self) -> Option<&HashMap<Sym, Handle>> {
+        self.table.imports(self.id)
+    }
+
+    pub fn ty(&self) -> Option<&TypeKind> {
+        self.table.ty(self.id)
+    }
+
+    pub fn span(&self) -> Option<&Span> {
+        self.table.span(self.id)
+    }
+
+    pub fn meta(&self) -> Option<&'a [Meta]> {
+        self.table.meta(self.id)
+    }
+
+    pub fn source(&self) -> Option<&Source<'a>> {
+        self.table.source(self.id)
+    }
+
+    pub fn impl_target(&self) -> Option<Entry<'_, 'a>> {
+        Some(Entry { id: self.table.impl_target(self.id)?, ..*self })
+    }
+
+    pub fn selfty(&self) -> Option<Entry<'_, 'a>> {
+        Some(Entry { id: self.table.selfty(self.id)?, ..*self })
+    }
+
+    pub fn name(&self) -> Option<Sym> {
+        self.table.name(self.id)
+    }
+}
+
+#[derive(Debug)]
+pub struct EntryMut<'t, 'a> {
+    table: &'t mut Table<'a>,
+    id: Handle,
+}
+
+impl<'t, 'a> EntryMut<'t, 'a> {
+    pub fn new(table: &'t mut Table<'a>, id: Handle) -> Self {
+        Self { table, id }
+    }
+
+    pub fn as_ref(&self) -> Entry<'_, 'a> {
+        Entry { table: self.table, id: self.id }
+    }
+
+    pub const fn id(&self) -> Handle {
+        self.id
+    }
+
+    /// Evaluates a [TypeExpression] in this entry's context
+    pub fn evaluate<Out>(&mut self, ty: &impl TypeExpression<Out>) -> Result<Out, tex::Error> {
+        let Self { table, id } = self;
+        ty.evaluate(table, *id)
+    }
+
+    pub fn categorize(&mut self) -> Result<(), cat::Error> {
+        cat::categorize(self.table, self.id)
+    }
+
+    /// Constructs a new Handle with the provided parent [Handle]
+    pub fn with_id(&mut self, parent: Handle) -> EntryMut<'_, 'a> {
+        EntryMut { table: self.table, id: parent }
+    }
+
+    pub fn nav(&mut self, path: &[PathPart]) -> Option<EntryMut<'_, 'a>> {
+        Some(EntryMut { id: self.table.nav(self.id, path)?, table: self.table })
+    }
+
+    pub fn new_entry(&mut self, kind: NodeKind) -> EntryMut<'_, 'a> {
+        let id = self.table.new_entry(self.id, kind);
+        self.with_id(id)
+    }
+
+    pub fn add_child(&mut self, name: Sym, child: Handle) -> Option<Handle> {
+        self.table.add_child(self.id, name, child)
+    }
+
+    pub fn set_ty(&mut self, kind: TypeKind) -> Option<TypeKind> {
+        self.table.set_ty(self.id, kind)
+    }
+
+    pub fn set_span(&mut self, span: Span) -> Option<Span> {
+        self.table.set_span(self.id, span)
+    }
+
+    pub fn set_meta(&mut self, meta: &'a [Meta]) -> Option<&'a [Meta]> {
+        self.table.set_meta(self.id, meta)
+    }
+
+    pub fn set_source(&mut self, source: Source<'a>) -> Option<Source<'a>> {
+        self.table.set_source(self.id, source)
+    }
+
+    pub fn set_impl_target(&mut self, target: Handle) -> Option<Handle> {
+        self.table.set_impl_target(self.id, target)
+    }
+
+    pub fn mark_use_item(&mut self) {
+        self.table.mark_use_item(self.id)
+    }
+
+    pub fn mark_impl_item(&mut self) {
+        self.table.mark_impl_item(self.id)
+    }
+}

compiler/cl-typeck/src/entry/display.rs

@@ -0,0 +1,100 @@
+use super::*;
+use crate::{format_utils::*, type_kind::Adt};
+use std::fmt::{self, Write};
+
+/// Printing the name of a named type stops infinite recursion
+fn write_name_or(h: Entry, f: &mut impl Write) -> fmt::Result {
+    match h.name() {
+        Some(name) => write!(f, "{name}"),
+        None => write!(f, "{h}"),
+    }
+}
+
+impl fmt::Display for Entry<'_, '_> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let Some(&kind) = self.kind() else {
+            return write!(f, "<invalid type: {}>", self.id);
+        };
+
+        if let Some(ty) = self.ty() {
+            match ty {
+                TypeKind::Instance(id) => write!(f, "{}", self.with_id(*id)),
+                TypeKind::Intrinsic(kind) => write!(f, "{kind}"),
+                TypeKind::Adt(adt) => write_adt(adt, self, f),
+                &TypeKind::Ref(id) => {
+                    f.write_str("&")?;
+                    let h_id = self.with_id(id);
+                    write_name_or(h_id, f)
+                }
+                TypeKind::Slice(id) => {
+                    write_name_or(self.with_id(*id), &mut f.delimit_with("[", "]"))
+                }
+                &TypeKind::Array(t, cnt) => {
+                    let mut f = f.delimit_with("[", "]");
+                    write_name_or(self.with_id(t), &mut f)?;
+                    write!(f, "; {cnt}")
+                }
+                TypeKind::Tuple(ids) => {
+                    let mut f = f.delimit_with("(", ")");
+                    for (index, &id) in ids.iter().enumerate() {
+                        if index > 0 {
+                            write!(f, ", ")?;
+                        }
+                        write_name_or(self.with_id(id), &mut f)?;
+                    }
+                    Ok(())
+                }
+                TypeKind::FnSig { args, rety } => {
+                    write!(f, "fn {} -> ", self.with_id(*args))?;
+                    write_name_or(self.with_id(*rety), f)
+                }
+                TypeKind::Empty => write!(f, "()"),
+                TypeKind::Never => write!(f, "!"),
+                TypeKind::Module => write!(f, "module?"),
+            }
+        } else {
+            write!(f, "{kind}")
+        }
+    }
+}
+
+fn write_adt(adt: &Adt, h: &Entry, f: &mut impl Write) -> fmt::Result {
+    match adt {
+        Adt::Enum(variants) => {
+            let mut variants = variants.iter();
+            separate(", ", || {
+                variants.next().map(|(name, def)| {
+                    move |f: &mut Delimit<_>| match def {
+                        Some(def) => {
+                            write!(f, "{name}: ")?;
+                            write_name_or(h.with_id(*def), f)
+                        }
+                        None => write!(f, "{name}"),
+                    }
+                })
+            })(f.delimit_with("enum {", "}"))
+        }
+        Adt::Struct(members) => {
+            let mut members = members.iter();
+            separate(", ", || {
+                let (name, vis, id) = members.next()?;
+                Some(move |f: &mut Delimit<_>| {
+                    write!(f, "{vis}{name}: ")?;
+                    write_name_or(h.with_id(*id), f)
+                })
+            })(f.delimit_with("struct {", "}"))
+        }
+        Adt::TupleStruct(members) => {
+            let mut members = members.iter();
+            separate(", ", || {
+                let (vis, def) = members.next()?;
+                Some(move |f: &mut Delimit<_>| {
+                    write!(f, "{vis}")?;
+                    write_name_or(h.with_id(*def), f)
+                })
+            })(f.delimit_with("struct (", ")"))
+        }
+        Adt::UnitStruct => write!(f, "struct"),
+        Adt::Union(_) => todo!("Display union types"),
+    }
+}

compiler/cl-typeck/src/handle.rs

@@ -1,187 +1,15 @@
-use crate::{definition::Def, path::Path, project::Project};
+//! A [Handle] uniquely represents an entry in the [Table](crate::table::Table)
+
 use cl_structures::index_map::*;
 
 // define the index types
 make_index! {
-    /// Uniquely represents a [Def][1] in the [Def][1] [Pool]
-    ///
-    /// [1]: crate::definition::Def
-    DefID,
+    /// Uniquely represents an entry in the [Table](crate::table::Table)
+    Handle,
 }
 
-/// A handle to a certain [Def] within a [Project]
-#[derive(Clone, Copy, Debug)]
-pub struct Handle<'prj, 'code> {
-    id: DefID,
-    prj: &'prj Project<'code>,
-}
-
-impl DefID {
-    /// Constructs a new [Handle] from this DefID and the provided [Project].
-    pub fn handle<'p, 'c>(self, prj: &'p Project<'c>) -> Option<Handle<'p, 'c>> {
-        Handle::new(self, prj)
-    }
-
-    /// Constructs a new [Handle] from this DefID and the provided [Project]
-    pub fn handle_unchecked<'p, 'c>(self, prj: &'p Project<'c>) -> Handle<'p, 'c> {
-        Handle::new_unchecked(self, prj)
-    }
-}
-
-impl<'p, 'c> Handle<'p, 'c> {
-    /// Constructs a new Handle from the provided [DefID] and [Project].
-    /// Returns [Some]\(Handle) if the [DefID] exists in the [Project].
-    pub fn new(id: DefID, prj: &'p Project<'c>) -> Option<Self> {
-        prj.pool.get(id).is_some().then_some(Self { id, prj })
-    }
-
-    /// Constructs a new Handle from the provided [DefID] and [Project] without checking membership.
-    /// Using the handle may cause panics or other unwanted (but defined) behavior.
-    pub fn new_unchecked(id: DefID, prj: &'p Project<'c>) -> Self {
-        Self { id, prj }
-    }
-
-    /// Gets the [Def] this handle points to.
-    pub fn get(self) -> Option<&'p Def<'c>> {
-        self.prj.pool.get(self.id)
-    }
-
-    pub fn navigate(self, path: Path) -> (Option<Self>, Option<Self>) {
-        match self.prj.get(path, self.id) {
-            Some((Some(ty), Some(vl), _)) => (Some(self.with(ty)), Some(self.with(vl))),
-            Some((_, Some(vl), _)) => (None, Some(self.with(vl))),
-            Some((Some(ty), _, _)) => (Some(self.with(ty)), None),
-            _ => (None, None),
-        }
-    }
-
-    /// Gets the [Project] this handle points to.
-    pub fn project(self) -> &'p Project<'c> {
-        self.prj
-    }
-
-    pub fn id(self) -> DefID {
-        self.id
-    }
-
-    // TODO: get parent, children, etc.
-
-    /// Gets a handle to the other ID within the same project
-    pub fn with(self, id: DefID) -> Self {
-        Self { id, ..self }
-    }
-}
-
-mod display {
-    use super::*;
-    use crate::{definition::*, format_utils::*};
-    use std::fmt::{self, Display, Write};
-
-    impl Display for DefID {
-        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-            self.0.fmt(f)
-        }
-    }
-
-    impl Display for Handle<'_, '_> {
-        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-            let Self { id, prj } = *self;
-            let Some(def) = prj.pool.get(id) else {
-                return write!(f, "<invalid type: {id}>");
-            };
-
-            // Match the type
-            match &def.kind {
-                DefKind::Undecided => write!(f, "<undecided>"),
-                DefKind::Impl(id) => write!(f, "impl {}", self.with(*id)),
-                DefKind::Use(id) => write!(f, "use inside {}", self.with(*id)),
-                DefKind::Type(kind) => match kind {
-                    TypeKind::Alias(None) => write!(f, "type"),
-                    TypeKind::Alias(Some(id)) => write!(f, "{}", self.with(*id)),
-                    TypeKind::Intrinsic(intrinsic) => write!(f, "{intrinsic}"),
-                    TypeKind::Adt(adt) => display_adt(self, adt, f),
-                    TypeKind::Ref(count, id) => {
-                        for _ in 0..*count {
-                            f.write_char('&')?;
-                        }
-                        self.with(*id).fmt(f)
-                    }
-                    TypeKind::Array(id, size) => {
-                        write!(f.delimit_with("[", "]"), "{}; {size}", self.with(*id))
-                    }
-                    TypeKind::Slice(id) => write!(f.delimit_with("[", "]"), "{}", self.with(*id)),
-                    TypeKind::Tuple(ids) => {
-                        let mut ids = ids.iter();
-                        separate(", ", || {
-                            let id = ids.next()?;
-                            Some(move |f: &mut Delimit<_>| write!(f, "{}", self.with(*id)))
-                        })(f.delimit_with("(", ")"))
-                    }
-                    TypeKind::FnSig { args, rety } => {
-                        write!(f, "fn {} -> {}", self.with(*args), self.with(*rety))
-                    }
-                    TypeKind::Empty => write!(f, "()"),
-                    TypeKind::Never => write!(f, "!"),
-                    TypeKind::Module => match def.name() {
-                        Some(name) => write!(f, "mod {name}"),
-                        None => write!(f, "mod"),
-                    },
-                },
-
-                DefKind::Value(kind) => match kind {
-                    ValueKind::Const(id) => write!(f, "const {}", self.with(*id)),
-                    ValueKind::Static(id) => write!(f, "static {}", self.with(*id)),
-                    ValueKind::Local(id) => write!(f, "local {}", self.with(*id)),
-                    ValueKind::Fn(id) => write!(f, "{}", self.with(*id)),
-                },
-            }
-        }
-    }
-
-    /// Formats an ADT: a continuation of [Handle::fmt]
-    fn display_adt(handle: &Handle, adt: &Adt, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match adt {
-            Adt::Enum(variants) => {
-                let mut variants = variants.iter();
-                separate(",", || {
-                    variants.next().map(|(name, def)| {
-                        move |f: &mut Delimit<_>| match def {
-                            Some(def) => write!(f, "\n{name}: {}", handle.with(*def)),
-                            None => write!(f, "\n{name}"),
-                        }
-                    })
-                })(f.delimit_with("enum {", "\n}"))
-            }
-            Adt::CLikeEnum(variants) => {
-                let mut variants = variants.iter();
-                separate(",", || {
-                    let (name, descrim) = variants.next()?;
-                    Some(move |f: &mut Delimit<_>| write!(f, "\n{name} = {descrim}"))
-                })(f.delimit_with("enum {", "\n}"))
-            }
-            Adt::FieldlessEnum => write!(f, "enum"),
-            Adt::Struct(members) => {
-                let mut members = members.iter();
-                separate(",", || {
-                    let (name, vis, id) = members.next()?;
-                    Some(move |f: &mut Delimit<_>| write!(f, "\n{vis}{name}: {}", handle.with(*id)))
-                })(f.delimit_with("struct {", "\n}"))
-            }
-            Adt::TupleStruct(members) => {
-                let mut members = members.iter();
-                separate(", ", || {
-                    let (vis, def) = members.next()?;
-                    Some(move |f: &mut Delimit<_>| write!(f, "{vis}{}", handle.with(*def)))
-                })(f.delimit_with("struct (", ")"))
-            }
-            Adt::UnitStruct => write!(f, "struct;"),
-            Adt::Union(variants) => {
-                let mut variants = variants.iter();
-                separate(",", || {
-                    let (name, def) = variants.next()?;
-                    Some(move |f: &mut Delimit<_>| write!(f, "\n{name}: {}", handle.with(*def)))
-                })(f.delimit_with("union {", "\n}"))
-            }
-        }
+impl std::fmt::Display for Handle {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        self.0.fmt(f)
     }
 }

compiler/cl-typeck/src/lib.rs

@@ -4,154 +4,71 @@
 //!
 //! This crate is a major work-in-progress.
 //!
-//! # The [Project](project::Project)™
-//! Contains [item definitions](definition) and type expression information.
+//! # The [Table](table::Table)™
+//! A directed graph of nodes and their dependencies.
 //!
-//! *Every* definition is itself a module, and can contain arbitrarily nested items
-//! as part of the [Module](module::Module) tree.
+//! Contains [item definitions](handle) and [type expression](type_expression) information.
 //!
-//! The Project keeps track of a *global intern pool* of definitions, which are
-//! trivially comparable by [DefID](key::DefID). Note that, for item definitions,
-//! identical types in different modules DO NOT COMPARE EQUAL under this constraint.
-//! However, so-called "anonymous" types *do not* follow this rule, as their
-//! definitions are constructed dynamically and ensured to be unique.
-// Note: it's a class invariant that named types are not added
-// to the anon-types list. Please keep it that way. ♥  Thanks!
+//! *Every* item is itself a module, and can contain arbitrarily nested items
+//! as part of the item graph
+//!
+//! The table, additionally, has some queues for use in external algorithms,
+//! detailed in the [stage] module.
 //!
 //! # Namespaces
-//! Within a Project, [definitions](definition::Def) are classified into two namespaces:
-//!
-//! ## Type Namespace:
-//! - Modules
-//! - Structs
-//! - Enums
-//! - Type aliases
-//!
-//! ## Value Namespace:
-//! - Functions
-//! - Constants
-//! - Static variables
-//!
-//! There is a *key* distinction between the two namespaces when it comes to
-//! [Path](path::Path) traversal: Only items in the Type Namespace will be considered
-//! as an intermediate path target. This means items in the Value namespace are
-//! entirely *opaque*, and form a one-way barrier. Items outside a Value can be
-//! referred to within the Value, but items inside a Value *cannot* be referred to
-//! outside the Value.
+//! Each item in the graph is given its own namespace, which is further separated into
+//! two distinct parts:
+//! - Children of an item are direct descendents (i.e. their `parent` is a handle to the item)
+//! - Imports of an item are indirect descendents created by `use` or `impl` directives. They are
+//!   shadowed by Children with the same name.
 //!
 //! # Order of operations:
-//! Currently, the process of type resolution goes as follows:
-//!
-//! 1. Traverse the AST, [collecting all Items into item definitions](name_collector)
-//! 2. Eagerly [resolve `use` imports](use_importer)
-//! 3. Traverse all [definitions](definition::Def), and [resolve the types for every
-//!    item](type_resolver)
-//! 4. TODO: Construct a typed AST for expressions, and type-check them
+//! For order-of-operations information, see the [stage] module.
 #![warn(clippy::all)]
 
-/*
-How do I flesh out modules in an incremental way?
-
-1. Visit all *modules* and create nodes in a module tree for them
-- This can be done by holding mutable references to submodules!
-
-
-Module:
-    values: Map(name -> Value),
-    types: Map(name -> Type),
-
-Value: Either
-    function: { signature: Type, body: FunctionBody }
-    static: { Mutability, ty: Type, init: ConstEvaluationResult }
-    const: { ty: Type, init: ConstEvaluationResult }
-
-*/
-
-pub mod handle;
-
-pub mod node;
-
-pub mod definition;
-
-pub mod module;
-
-pub mod path;
-
-pub mod project;
-
-pub mod name_collector;
-
-pub mod use_importer;
-
-pub mod type_resolver;
-
-pub mod inference;
-
 pub(crate) mod format_utils;
 
-/*
+pub mod table;
 
-LET THERE BE NOTES:
+pub mod handle;
 
-/// What is an inference rule?
-/// An inference rule is a specification with a set of predicates and a judgement
+pub mod entry;
 
-/// Let's give every type an ID
-struct TypeID(usize);
+pub mod source;
 
-/// Let's give every type some data:
+pub mod type_kind;
 
-struct TypeDef<'def> {
-    name: String,
-    definition: &'def Item,
+pub mod type_expression;
+
+pub mod stage {
+    //! Type collection, evaluation, checking, and inference passes.
+    //!
+    //! # Order of operations
+    //! 1. [mod@populate]: Populate the graph with nodes for every named item.
+    //! 2. [mod@import]: Import the `use` nodes discovered in [Stage 1](populate).
+    //! 3. [mod@categorize]: Categorize the nodes according to textual type information.
+    //!    - Creates anonymous types (`fn(T) -> U`, `&T`, `[T]`, etc.) as necessary to fill in the
+    //!      type graph
+    //!    - Creates a new struct type for every enum struct-variant.
+    //! 4. [mod@implement]: Import members of implementation modules into types.
+
+    pub use populate::Populator;
+    /// Stage 1: Populate the graph with nodes.
+    pub mod populate;
+
+    pub use import::import;
+    /// Stage 2: Import the `use` nodes discovered in Stage 1.
+    pub mod import;
+
+    pub use categorize::categorize;
+    /// Stage 3: Categorize the nodes according to textual type information.
+    pub mod categorize;
+
+    pub use implement::implement;
+    /// Stage 4: Import members of `impl` blocks into their corresponding types.
+    pub mod implement;
+
+    // TODO: Make type inference stage 5
+    // TODO: Use the type information stored in the [table]
+    pub mod infer;
 }
-
-and store them in a big vector of type descriptions:
-
-struct TypeMap<'def> {
-    types: Vec<TypeDef<'def>>,
-}
-// todo: insertion of a type should yield a TypeID
-// todo: impl index with TypeID
-
-Let's store type information as either a concrete type or a generic type:
-
-/// The Type struct represents all valid types, and can be trivially equality-compared
-pub struct Type {
-    /// You can only have a pointer chain 65535 pointers long.
-    ref_depth: u16,
-    kind: TKind,
-}
-pub enum TKind {
-    Concrete(TypeID),
-    Generic(usize),
-}
-
-And assume I can specify a rule based on its inputs and outputs:
-
-Rule {
-    operation: If,
-    /// The inputs field is populated by
-    inputs: [Concrete(BOOL), Generic(0), Generic(0)],
-    outputs: Generic(0),
-    /// This rule is compiler-intrinsic!
-    through: None,
-}
-
-Rule {
-    operation: Add,
-    inputs: [Concrete(I32), Concrete(I32)],
-    outputs: Concrete(I32),
-    /// This rule is not compiler-intrinsic (it is overloaded!)
-    through: Some(&ImplAddForI32::Add),
-}
-
-
-
-These rules can be stored in some kind of rule database:
-
-let rules: Hashmap<Operation, Vec<Rule>> {
-
-}
-
-*/

compiler/cl-typeck/src/module.rs

@@ -1,71 +0,0 @@
-//! A [Module] is a node in the Module Tree (a component of a
-//! [Project](crate::project::Project))
-use cl_ast::Sym;
-use cl_structures::index_map::MapIndex;
-
-use crate::handle::DefID;
-use std::collections::HashMap;
-
-/// A [Module] is a node in the Module Tree (a component of a
-/// [Project](crate::project::Project)).
-#[derive(Clone, Debug, Default, PartialEq, Eq)]
-pub struct Module {
-    pub parent: Option<DefID>,
-    pub types: HashMap<Sym, DefID>,
-    pub values: HashMap<Sym, DefID>,
-    pub imports: Vec<DefID>,
-}
-
-impl Module {
-    pub fn new(parent: DefID) -> Self {
-        Self { parent: Some(parent), ..Default::default() }
-    }
-    pub fn with_optional_parent(parent: Option<DefID>) -> Self {
-        Self { parent, ..Default::default() }
-    }
-
-    pub fn get(&self, name: Sym) -> (Option<DefID>, Option<DefID>) {
-        (self.get_type(name), self.get_value(name))
-    }
-    pub fn get_type(&self, name: Sym) -> Option<DefID> {
-        self.types.get(&name).copied()
-    }
-    pub fn get_value(&self, name: Sym) -> Option<DefID> {
-        self.values.get(&name).copied()
-    }
-
-    /// Inserts a type with the provided [name](str) and [id](DefID)
-    pub fn insert_type(&mut self, name: Sym, id: DefID) -> Option<DefID> {
-        self.types.insert(name, id)
-    }
-
-    /// Inserts a value with the provided [name](str) and [id](DefID)
-    pub fn insert_value(&mut self, name: Sym, id: DefID) -> Option<DefID> {
-        self.values.insert(name, id)
-    }
-}
-
-impl std::fmt::Display for Module {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-        let Self { parent, types, values, imports } = self;
-        if let Some(parent) = parent {
-            writeln!(f, "Parent: {}", parent.get())?;
-        }
-        for (name, table) in [("Types", types), ("Values", values)] {
-            if table.is_empty() {
-                continue;
-            }
-            writeln!(f, "{name}:")?;
-            for (name, id) in table.iter() {
-                writeln!(f, "    {name} => {id}")?;
-            }
-        }
-        if !imports.is_empty() {
-            write!(f, "Imports:")?;
-            for id in imports {
-                write!(f, "{id},")?;
-            }
-        }
-        Ok(())
-    }
-}

compiler/cl-typeck/src/name_collector.rs

@@ -1,218 +0,0 @@
-//! Performs step 1 of type checking: Collecting all the names of things into [Module] units
-use crate::{
-    definition::{Def, DefKind},
-    handle::DefID,
-    module::Module as Mod,
-    node::{Node, NodeSource},
-    project::Project as Prj,
-};
-use cl_ast::{ast_visitor::Visit, *};
-use std::mem;
-
-#[derive(Debug)]
-pub struct NameCollector<'prj, 'a> {
-    path: cl_ast::Path,
-    prj: &'prj mut Prj<'a>,
-    parent: DefID,
-    retval: Option<DefID>,
-}
-
-impl<'prj, 'a> NameCollector<'prj, 'a> {
-    /// Constructs a new [NameCollector] out of a [Project](Prj)
-    pub fn new(prj: &'prj mut Prj<'a>) -> Self {
-        Self { parent: prj.root, prj, path: Default::default(), retval: None }
-    }
-    /// Constructs a new [NameCollector] out of a [Project](Prj) and a parent [DefID]
-    pub fn with_root(prj: &'prj mut Prj<'a>, parent: DefID) -> Self {
-        Self { prj, parent, path: Default::default(), retval: None }
-    }
-    /// Runs the provided function with the given parent
-    pub fn with_parent<F, N>(&mut self, parent: DefID, node: N, f: F)
-    where F: FnOnce(&mut Self, N) {
-        let parent = mem::replace(&mut self.parent, parent);
-        f(self, node);
-        self.parent = parent;
-    }
-    /// Extracts the return value from the provided function
-    pub fn returns<F, N>(&mut self, node: N, f: F) -> Option<DefID>
-    where F: FnOnce(&mut Self, N) {
-        let out = self.retval.take();
-        f(self, node);
-        mem::replace(&mut self.retval, out)
-    }
-}
-
-impl<'prj, 'a> Visit<'a> for NameCollector<'prj, 'a> {
-    fn visit_item(&mut self, i: &'a Item) {
-        let Item { extents: _, attrs, vis, kind } = i;
-        if let Some(def) = self.returns(kind, Self::visit_item_kind) {
-            self.prj[def].set_meta(&attrs.meta).set_vis(*vis);
-        }
-    }
-    fn visit_module(&mut self, m: &'a Module) {
-        let Self { prj, parent, path, retval: _ } = self;
-        let Module { name, kind } = m;
-
-        let def = Def {
-            module: Mod::new(*parent),
-            kind: DefKind::Undecided,
-            node: Node::new(path.clone(), Some(NodeSource::Module(m))),
-        };
-        let id = prj.pool.insert(def);
-        prj[*parent].module.insert_type(*name, id);
-        self.path.push(PathPart::Ident(*name));
-        self.with_parent(id, kind, Self::visit_module_kind);
-        self.path.pop();
-        self.retval = Some(id);
-    }
-    fn visit_alias(&mut self, a: &'a Alias) {
-        let Self { prj, parent, path, retval: _ } = self;
-        let Alias { to: name, from: _ } = a;
-
-        let def = Def {
-            module: Mod::new(*parent),
-            kind: DefKind::Undecided,
-            node: Node::new(path.clone(), Some(NodeSource::Alias(a))),
-        };
-        let id = prj.pool.insert(def);
-        prj[*parent].module.insert_type(*name, id);
-
-        self.retval = Some(id);
-    }
-    fn visit_enum(&mut self, e: &'a Enum) {
-        let Self { prj, parent, path, retval: _ } = self;
-        let Enum { name, kind } = e;
-
-        let def = Def {
-            module: Mod::new(*parent),
-            kind: DefKind::Undecided,
-            node: Node::new(path.clone(), Some(NodeSource::Enum(e))),
-        };
-        let id = prj.pool.insert(def);
-        prj[*parent].module.insert_type(*name, id);
-
-        self.with_parent(id, kind, Self::visit_enum_kind);
-        self.retval = Some(id);
-    }
-    fn visit_variant(&mut self, v: &'a Variant) {
-        let Self { path, prj, parent, retval: _ } = self;
-        let Variant { name, kind } = v;
-
-        let def = Def {
-            module: Mod::new(*parent),
-            kind: DefKind::Undecided,
-            node: Node::new(path.clone(), Some(NodeSource::Variant(v))),
-        };
-        let id = prj.pool.insert(def);
-        prj[*parent].module.insert_type(*name, id);
-
-        self.with_parent(id, kind, Self::visit_variant_kind);
-        self.retval = Some(id);
-    }
-    fn visit_struct(&mut self, s: &'a Struct) {
-        let Self { prj, parent, path, retval: _ } = self;
-        let Struct { name, kind } = s;
-
-        let def = Def {
-            module: Mod::new(*parent),
-            kind: DefKind::Undecided,
-            node: Node::new(path.clone(), Some(NodeSource::Struct(s))),
-        };
-        let id = prj.pool.insert(def);
-        prj[*parent].module.insert_type(*name, id);
-
-        self.with_parent(id, kind, Self::visit_struct_kind);
-        self.retval = Some(id);
-    }
-    fn visit_const(&mut self, c: &'a Const) {
-        let Self { prj, parent, path, retval: _ } = self;
-        let Const { name, ty: _, init } = c;
-
-        let def = Def {
-            module: Mod::new(*parent),
-            kind: DefKind::Undecided,
-            node: Node::new(path.clone(), Some(NodeSource::Const(c))),
-        };
-        let id = prj.pool.insert(def);
-        prj[*parent].module.insert_value(*name, id);
-
-        self.with_parent(id, &**init, Self::visit_expr);
-        self.retval = Some(id);
-    }
-    fn visit_static(&mut self, s: &'a Static) {
-        let Self { prj, parent, path, retval: _ } = self;
-        let Static { name, mutable: _, ty: _, init } = s;
-
-        let def = Def {
-            module: Mod::new(*parent),
-            kind: DefKind::Undecided,
-            node: Node::new(path.clone(), Some(NodeSource::Static(s))),
-        };
-        let id = prj.pool.insert(def);
-        prj[*parent].module.insert_value(*name, id);
-
-        self.with_parent(id, &**init, Self::visit_expr);
-        self.retval = Some(id);
-    }
-    fn visit_function(&mut self, f: &'a Function) {
-        let Self { prj, parent, path, retval: _ } = self;
-        let Function { name, body, .. } = f;
-
-        let def = Def {
-            module: Mod::new(*parent),
-            kind: DefKind::Undecided,
-            node: Node::new(path.clone(), Some(NodeSource::Function(f))),
-        };
-        let id = prj.pool.insert(def);
-        prj[*parent].module.insert_value(*name, id);
-
-        if let Some(body) = body {
-            self.with_parent(id, body, Self::visit_block);
-        }
-        self.retval = Some(id);
-    }
-    fn visit_impl(&mut self, i: &'a Impl) {
-        let Self { prj, parent, path, retval: _ } = self;
-        let Impl { target: _, body } = i;
-        let def = Def {
-            module: Mod::new(*parent),
-            kind: DefKind::Undecided,
-            node: Node::new(path.clone(), Some(NodeSource::Impl(i))),
-        };
-        let id = prj.pool.insert(def);
-
-        // items will get reparented after name collection, when target is available
-        self.with_parent(id, body, Self::visit_file);
-
-        self.retval = Some(id);
-    }
-    fn visit_use(&mut self, u: &'a Use) {
-        let Self { prj, parent, path, retval } = self;
-        let def = Def {
-            module: Mod::new(*parent),
-            kind: DefKind::Use(*parent),
-            node: Node::new(path.clone(), Some(NodeSource::Use(u))),
-        };
-
-        let id = prj.pool.insert(def);
-        prj[*parent].module.imports.push(id);
-
-        *retval = Some(id);
-    }
-    fn visit_let(&mut self, l: &'a Let) {
-        let Self { prj, parent, path, retval: _ } = self;
-        let Let { name, init, .. } = l;
-        let def = Def {
-            module: Mod::new(*parent),
-            kind: DefKind::Undecided,
-            node: Node::new(path.clone(), Some(NodeSource::Local(l))),
-        };
-
-        let id = prj.pool.insert(def);
-        prj[*parent].module.insert_value(*name, id);
-        if let Some(expr) = init {
-            self.visit_expr(expr)
-        }
-        self.retval = Some(id)
-    }
-}

compiler/cl-typeck/src/node.rs

@@ -1,214 +0,0 @@
-//! A [Node] contains the [NodeSource] and [Item] metadata for any
-//! [Def](crate::definition::Def), as well as the [Path] of the
-//! containing [Module].
-//!
-//! [Node]s are collected by the [Node Sorcerer](sorcerer),
-//! an AST visitor that pairs [NodeSource]s with their surrounding
-//! context ([Path], [struct@Span], [Meta], [Visibility])
-
-use cl_ast::ast::*;
-use cl_structures::span::Span;
-use std::fmt;
-
-#[derive(Clone, Debug, PartialEq, Eq)]
-pub struct Node<'a> {
-    pub in_path: Path,
-    pub span: &'a Span,
-    pub meta: &'a [Meta],
-    pub vis: Visibility,
-    pub kind: Option<NodeSource<'a>>,
-}
-
-impl<'a> Node<'a> {
-    pub fn new(path: Path, kind: Option<NodeSource<'a>>) -> Self {
-        const DUMMY_SPAN: Span = Span::dummy();
-        Self { in_path: path, span: &DUMMY_SPAN, meta: &[], vis: Visibility::Public, kind }
-    }
-}
-
-#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
-pub enum NodeSource<'a> {
-    Root,
-    Module(&'a Module),
-    Alias(&'a Alias),
-    Enum(&'a Enum),
-    Variant(&'a Variant),
-    Struct(&'a Struct),
-    Const(&'a Const),
-    Static(&'a Static),
-    Function(&'a Function),
-    Local(&'a Let),
-    Impl(&'a Impl),
-    Use(&'a Use),
-    Ty(&'a TyKind),
-}
-
-impl<'a> NodeSource<'a> {
-    pub fn name(&self) -> Option<Sym> {
-        match self {
-            NodeSource::Root => None,
-            NodeSource::Module(v) => Some(v.name),
-            NodeSource::Alias(v) => Some(v.to),
-            NodeSource::Enum(v) => Some(v.name),
-            NodeSource::Variant(v) => Some(v.name),
-            NodeSource::Struct(v) => Some(v.name),
-            NodeSource::Const(v) => Some(v.name),
-            NodeSource::Static(v) => Some(v.name),
-            NodeSource::Function(v) => Some(v.name),
-            NodeSource::Local(l) => Some(l.name),
-            NodeSource::Impl(_) | NodeSource::Use(_) | NodeSource::Ty(_) => None,
-        }
-    }
-
-    /// Returns `true` if this [NodeSource] defines a named value
-    pub fn is_named_value(&self) -> bool {
-        matches!(self, Self::Const(_) | Self::Static(_) | Self::Function(_))
-    }
-
-    /// Returns `true` if this [NodeSource] defines a named type
-    pub fn is_named_type(&self) -> bool {
-        matches!(
-            self,
-            Self::Module(_) | Self::Alias(_) | Self::Enum(_) | Self::Struct(_)
-        )
-    }
-
-    /// Returns `true` if this [NodeSource] refers to a [Ty] with no name
-    pub fn is_anon_type(&self) -> bool {
-        matches!(self, Self::Ty(_))
-    }
-
-    /// Returns `true` if this [NodeSource] refers to an [Impl] block
-    pub fn is_impl(&self) -> bool {
-        matches!(self, Self::Impl(_))
-    }
-
-    /// Returns `true` if this [NodeSource] refers to a [Use] import
-    pub fn is_use_import(&self) -> bool {
-        matches!(self, Self::Use(_))
-    }
-}
-
-impl fmt::Display for NodeSource<'_> {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            Self::Root => "🌳 root 🌳".fmt(f),
-            Self::Module(arg0) => arg0.fmt(f),
-            Self::Alias(arg0) => arg0.fmt(f),
-            Self::Enum(arg0) => arg0.fmt(f),
-            Self::Variant(arg0) => arg0.fmt(f),
-            Self::Struct(arg0) => arg0.fmt(f),
-            Self::Const(arg0) => arg0.fmt(f),
-            Self::Static(arg0) => arg0.fmt(f),
-            Self::Function(arg0) => arg0.fmt(f),
-            Self::Impl(arg0) => arg0.fmt(f),
-            Self::Use(arg0) => arg0.fmt(f),
-            Self::Ty(arg0) => arg0.fmt(f),
-            Self::Local(arg0) => arg0.fmt(f),
-        }
-    }
-}
-
-pub mod sorcerer {
-    //! An [AST](cl_ast) analysis pass that collects [Node] entries.
-
-    use super::{Node, NodeSource};
-    use cl_ast::{ast::*, ast_visitor::visit::*};
-    use cl_structures::span::Span;
-    use std::mem;
-
-    /// An AST analysis pass that collects [Node]s
-    #[derive(Clone, Debug)]
-    pub struct NodeSorcerer<'a> {
-        path: Path,
-        parts: Parts<'a>,
-        defs: Vec<Node<'a>>,
-    }
-
-    type Parts<'a> = (&'a Span, &'a [Meta], Visibility);
-
-    impl<'a> NodeSorcerer<'a> {
-        pub fn into_defs(self) -> Vec<Node<'a>> {
-            self.defs
-        }
-
-        fn with_parts<F>(&mut self, s: &'a Span, a: &'a [Meta], v: Visibility, f: F)
-        where F: FnOnce(&mut Self) {
-            let parts = mem::replace(&mut self.parts, (s, a, v));
-            f(self);
-            self.parts = parts;
-        }
-
-        fn with_only_span<F>(&mut self, span: &'a Span, f: F)
-        where F: FnOnce(&mut Self) {
-            self.with_parts(span, &[], Visibility::Public, f)
-        }
-
-        fn push(&mut self, kind: NodeSource<'a>) {
-            let Self { path, parts, defs } = self;
-            let (span, meta, vis) = *parts;
-
-            defs.push(Node { in_path: path.clone(), span, meta, vis, kind: Some(kind) })
-        }
-    }
-
-    impl Default for NodeSorcerer<'_> {
-        fn default() -> Self {
-            const DPARTS: Parts = (&Span::dummy(), &[], Visibility::Private);
-            Self {
-                path: Path { absolute: true, ..Default::default() },
-                parts: DPARTS,
-                defs: Default::default(),
-            }
-        }
-    }
-
-    impl<'a> Visit<'a> for NodeSorcerer<'a> {
-        fn visit_module(&mut self, m: &'a Module) {
-            let Module { name, kind } = m;
-            self.path.push(PathPart::Ident(*name));
-            self.visit_module_kind(kind);
-            self.path.pop();
-        }
-        fn visit_item(&mut self, i: &'a Item) {
-            let Item { extents, attrs, vis, kind } = i;
-            self.with_parts(extents, &attrs.meta, *vis, |v| {
-                v.visit_item_kind(kind);
-            });
-        }
-        fn visit_ty(&mut self, t: &'a Ty) {
-            let Ty { extents, kind } = t;
-            self.with_only_span(extents, |v| {
-                v.push(NodeSource::Ty(kind));
-                v.visit_ty_kind(kind);
-            });
-        }
-        fn visit_stmt(&mut self, s: &'a Stmt) {
-            let Stmt { extents, kind, semi } = s;
-            self.with_only_span(extents, |d| {
-                d.visit_stmt_kind(kind);
-                d.visit_semi(semi);
-            })
-        }
-        fn visit_item_kind(&mut self, kind: &'a ItemKind) {
-            match kind {
-                ItemKind::Module(i) => self.push(NodeSource::Module(i)),
-                ItemKind::Alias(i) => self.push(NodeSource::Alias(i)),
-                ItemKind::Enum(i) => self.push(NodeSource::Enum(i)),
-                ItemKind::Struct(i) => self.push(NodeSource::Struct(i)),
-                ItemKind::Const(i) => self.push(NodeSource::Const(i)),
-                ItemKind::Static(i) => self.push(NodeSource::Static(i)),
-                ItemKind::Function(i) => self.push(NodeSource::Function(i)),
-                ItemKind::Impl(i) => self.push(NodeSource::Impl(i)),
-                ItemKind::Use(i) => self.push(NodeSource::Use(i)),
-            }
-            or_visit_item_kind(self, kind);
-        }
-        fn visit_stmt_kind(&mut self, kind: &'a StmtKind) {
-            if let StmtKind::Local(l) = kind {
-                self.push(NodeSource::Local(l))
-            }
-            or_visit_stmt_kind(self, kind);
-        }
-    }
-}

compiler/cl-typeck/src/path.rs

@@ -1,60 +0,0 @@
-//! A [Path] is a borrowed view of an [AST Path](AstPath)
-use cl_ast::{Path as AstPath, PathPart};
-
-#[derive(Clone, Copy, Debug, PartialEq, Eq)]
-pub struct Path<'p> {
-    pub absolute: bool,
-    pub parts: &'p [PathPart],
-}
-
-impl<'p> Path<'p> {
-    pub fn new(path: &'p AstPath) -> Self {
-        let AstPath { absolute, parts } = path;
-        Self { absolute: *absolute, parts }
-    }
-    pub fn relative(self) -> Self {
-        Self { absolute: false, ..self }
-    }
-    pub fn pop_front(self) -> Option<Self> {
-        let Self { absolute, parts } = self;
-        Some(Self { absolute, parts: parts.get(1..)? })
-    }
-    pub fn front(self) -> Option<Self> {
-        let Self { absolute, parts } = self;
-        Some(Self { absolute, parts: parts.get(..1)? })
-    }
-    pub fn is_empty(&self) -> bool {
-        self.parts.is_empty()
-    }
-    pub fn len(&self) -> usize {
-        self.parts.len()
-    }
-    pub fn first(&self) -> Option<&PathPart> {
-        self.parts.first()
-    }
-}
-
-impl<'p> From<&'p AstPath> for Path<'p> {
-    fn from(value: &'p AstPath) -> Self {
-        Self::new(value)
-    }
-}
-impl AsRef<[PathPart]> for Path<'_> {
-    fn as_ref(&self) -> &[PathPart] {
-        self.parts
-    }
-}
-
-impl std::fmt::Display for Path<'_> {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        const SEPARATOR: &str = "::";
-        let Self { absolute, parts } = self;
-        if *absolute {
-            write!(f, "{SEPARATOR}")?
-        }
-        for (idx, part) in parts.iter().enumerate() {
-            write!(f, "{}{part}", if idx > 0 { SEPARATOR } else { "" })?;
-        }
-        Ok(())
-    }
-}

compiler/cl-typeck/src/project.rs

@@ -1,376 +0,0 @@
-//! A [Project] contains a tree of [Def]initions, referred to by their [Path]
-use crate::{
-    definition::{Def, DefKind, TypeKind},
-    handle::DefID,
-    module,
-    node::{Node, NodeSource},
-    path::Path,
-};
-use cl_ast::PathPart;
-use cl_structures::index_map::IndexMap;
-use std::{
-    collections::HashMap,
-    ops::{Index, IndexMut},
-};
-
-use self::evaluate::EvaluableTypeExpression;
-
-#[derive(Clone, Debug)]
-pub struct Project<'a> {
-    pub pool: IndexMap<DefID, Def<'a>>,
-    /// Stores anonymous tuples, function pointer types, etc.
-    pub anon_types: HashMap<TypeKind, DefID>,
-    pub root: DefID,
-}
-
-impl Project<'_> {
-    pub fn new() -> Self {
-        Self::default()
-    }
-}
-
-impl Default for Project<'_> {
-    fn default() -> Self {
-        const ROOT_PATH: cl_ast::Path = cl_ast::Path { absolute: true, parts: Vec::new() };
-
-        let mut pool = IndexMap::default();
-        let root = pool.insert(Def {
-            module: Default::default(),
-            kind: DefKind::Type(TypeKind::Module),
-            node: Node::new(ROOT_PATH, Some(NodeSource::Root)),
-        });
-        let never = pool.insert(Def {
-            module: module::Module::new(root),
-            kind: DefKind::Type(TypeKind::Never),
-            node: Node::new(ROOT_PATH, None),
-        });
-        let empty = pool.insert(Def {
-            module: module::Module::new(root),
-            kind: DefKind::Type(TypeKind::Empty),
-            node: Node::new(ROOT_PATH, None),
-        });
-
-        let mut anon_types = HashMap::new();
-        anon_types.insert(TypeKind::Empty, empty);
-        anon_types.insert(TypeKind::Never, never);
-
-        Self { pool, root, anon_types }
-    }
-}
-
-impl<'a> Project<'a> {
-    pub fn parent_of(&self, module: DefID) -> Option<DefID> {
-        self[module].module.parent
-    }
-
-    pub fn root_of(&self, module: DefID) -> DefID {
-        match self.parent_of(module) {
-            Some(module) => self.root_of(module),
-            None => module,
-        }
-    }
-
-    /// Returns the DefID of the Self type within the given DefID's context
-    pub fn selfty_of(&self, node: DefID) -> Option<DefID> {
-        match self[node].kind {
-            DefKind::Impl(id) => Some(id),
-            DefKind::Type(_) => Some(node),
-            _ => self.selfty_of(self.parent_of(node)?),
-        }
-    }
-
-    pub fn get<'p>(
-        &self,
-        path: Path<'p>,
-        within: DefID,
-    ) -> Option<(Option<DefID>, Option<DefID>, Path<'p>)> {
-        if path.absolute {
-            return self.get(path.relative(), self.root_of(within));
-        }
-        match path.as_ref() {
-            [PathPart::SuperKw, ..] => self.get(path.pop_front()?, self.parent_of(within)?),
-            [PathPart::SelfTy, ..] => self.get(path.pop_front()?, self.selfty_of(within)?),
-            [PathPart::SelfKw, ..] => self.get(path.pop_front()?, within),
-            [PathPart::Ident(name)] => {
-                let (ty, val) = self[within].module.get(*name);
-
-                // Transparent nodes can be looked through in reverse
-                if self[within].is_transparent() {
-                    let lookback = self.parent_of(within).and_then(|p| self.get(path, p));
-                    if let Some((subty, subval, path)) = lookback {
-                        return Some((ty.or(subty), val.or(subval), path));
-                    }
-                }
-                Some((ty, val, path.pop_front()?))
-            }
-            [PathPart::Ident(name), ..] => {
-                // TODO: This is currently too permissive, and treats undecided nodes as if they're
-                // always transparent, among other issues.
-                let (tysub, _, _) = match self[within].is_transparent() {
-                    true => self.get(path.front()?, within)?,
-                    false => (None, None, path),
-                };
-                let ty = self[within].module.get_type(*name).or(tysub)?;
-                self.get(path.pop_front()?, ty)
-            }
-            [] => Some((Some(within), None, path)),
-        }
-    }
-
-    /// Resolves a path within a module tree, finding the innermost module.
-    /// Returns the remaining path parts.
-    pub fn get_type<'p>(&self, path: Path<'p>, within: DefID) -> Option<(DefID, Path<'p>)> {
-        if path.absolute {
-            self.get_type(path.relative(), self.root_of(within))
-        } else if let Some(front) = path.first() {
-            let module = &self[within].module;
-            match front {
-                PathPart::SelfKw => self.get_type(path.pop_front()?, within),
-                PathPart::SuperKw => self.get_type(path.pop_front()?, module.parent?),
-                PathPart::SelfTy => self.get_type(path.pop_front()?, self.selfty_of(within)?),
-                PathPart::Ident(name) => match module.types.get(name) {
-                    Some(&submodule) => self.get_type(path.pop_front()?, submodule),
-                    None => Some((within, path)),
-                },
-            }
-        } else {
-            Some((within, path))
-        }
-    }
-
-    /// Inserts the type returned by the provided closure iff the TypeKind doesn't already exist
-    ///
-    /// Assumes `kind` uniquely identifies the type!
-    pub fn insert_anonymous_type(
-        &mut self,
-        kind: TypeKind,
-        def: impl FnOnce() -> Def<'a>,
-    ) -> DefID {
-        *(self
-            .anon_types
-            .entry(kind)
-            .or_insert_with(|| self.pool.insert(def())))
-    }
-
-    pub fn evaluate<T>(&mut self, expr: &T, parent: DefID) -> Result<T::Out, String>
-    where T: EvaluableTypeExpression {
-        expr.evaluate(self, parent)
-    }
-}
-
-impl<'a> Index<DefID> for Project<'a> {
-    type Output = Def<'a>;
-    fn index(&self, index: DefID) -> &Self::Output {
-        &self.pool[index]
-    }
-}
-impl IndexMut<DefID> for Project<'_> {
-    fn index_mut(&mut self, index: DefID) -> &mut Self::Output {
-        &mut self.pool[index]
-    }
-}
-
-pub mod evaluate {
-    //! An [EvaluableTypeExpression] is a component of a type expression tree
-    //! or an intermediate result of expression evaluation.
-
-    use super::*;
-    use crate::module;
-    use cl_ast::{Sym, Ty, TyArray, TyFn, TyKind, TyRef, TySlice, TyTuple};
-
-    /// Things that can be evaluated as a type expression
-    pub trait EvaluableTypeExpression {
-        /// The result of type expression evaluation
-        type Out;
-        fn evaluate(&self, prj: &mut Project, parent: DefID) -> Result<Self::Out, String>;
-    }
-
-    impl EvaluableTypeExpression for Ty {
-        type Out = DefID;
-        fn evaluate(&self, prj: &mut Project, id: DefID) -> Result<DefID, String> {
-            self.kind.evaluate(prj, id)
-        }
-    }
-
-    impl EvaluableTypeExpression for TyKind {
-        type Out = DefID;
-        fn evaluate(&self, prj: &mut Project, parent: DefID) -> Result<DefID, String> {
-            let id = match self {
-                // TODO: reduce duplication here
-                TyKind::Never => prj.anon_types[&TypeKind::Never],
-                TyKind::Empty => prj.anon_types[&TypeKind::Empty],
-                // TyKind::Path must be looked up explicitly
-                TyKind::Path(path) => path.evaluate(prj, parent)?,
-                TyKind::Slice(slice) => slice.evaluate(prj, parent)?,
-                TyKind::Array(array) => array.evaluate(prj, parent)?,
-                TyKind::Tuple(tup) => tup.evaluate(prj, parent)?,
-                TyKind::Ref(tyref) => tyref.evaluate(prj, parent)?,
-                TyKind::Fn(tyfn) => tyfn.evaluate(prj, parent)?,
-            };
-            // println!("{self} => {id:?}");
-
-            Ok(id)
-        }
-    }
-
-    impl EvaluableTypeExpression for Sym {
-        type Out = DefID;
-
-        fn evaluate(&self, prj: &mut Project, parent: DefID) -> Result<Self::Out, String> {
-            prj[parent]
-                .module
-                .types
-                .get(self)
-                .copied()
-                .ok_or_else(|| format!("{self} is not a member of {:?}", prj[parent].name()))
-        }
-    }
-
-    impl EvaluableTypeExpression for TySlice {
-        type Out = DefID;
-
-        fn evaluate(&self, prj: &mut Project, parent: DefID) -> Result<Self::Out, String> {
-            let ty = self.ty.evaluate(prj, parent)?;
-            let root = prj.root;
-            let id = prj.insert_anonymous_type(TypeKind::Slice(ty), move || Def {
-                module: module::Module::new(root),
-                node: Node::new(Default::default(), None),
-                kind: DefKind::Type(TypeKind::Slice(ty)),
-            });
-
-            Ok(id)
-        }
-    }
-
-    impl EvaluableTypeExpression for TyArray {
-        type Out = DefID;
-
-        fn evaluate(&self, prj: &mut Project, parent: DefID) -> Result<Self::Out, String> {
-            let kind = TypeKind::Array(self.ty.evaluate(prj, parent)?, self.count);
-            let root = prj.root;
-            let id = prj.insert_anonymous_type(kind.clone(), move || Def {
-                module: module::Module::new(root),
-                node: Node::new(Default::default(), None),
-                kind: DefKind::Type(kind),
-            });
-
-            Ok(id)
-        }
-    }
-
-    impl EvaluableTypeExpression for TyTuple {
-        type Out = DefID;
-        fn evaluate(&self, prj: &mut Project, parent: DefID) -> Result<DefID, String> {
-            let types = self.types.evaluate(prj, parent)?;
-            let root = prj.root;
-            let id = prj.insert_anonymous_type(TypeKind::Tuple(types.clone()), move || Def {
-                module: module::Module::new(root),
-                node: Node::new(Default::default(), None),
-                kind: DefKind::Type(TypeKind::Tuple(types)),
-            });
-
-            Ok(id)
-        }
-    }
-    impl EvaluableTypeExpression for TyRef {
-        type Out = DefID;
-        fn evaluate(&self, prj: &mut Project, parent: DefID) -> Result<DefID, String> {
-            let TyRef { count, mutable: _, to } = self;
-            let to = to.evaluate(prj, parent)?;
-
-            let root = prj.root;
-            let id = prj.insert_anonymous_type(TypeKind::Ref(*count, to), move || Def {
-                module: module::Module::new(root),
-                node: Node::new(Default::default(), None),
-                kind: DefKind::Type(TypeKind::Ref(*count, to)),
-            });
-            Ok(id)
-        }
-    }
-    impl EvaluableTypeExpression for TyFn {
-        type Out = DefID;
-        fn evaluate(&self, prj: &mut Project, parent: DefID) -> Result<DefID, String> {
-            let TyFn { args, rety } = self;
-
-            let args = args.evaluate(prj, parent)?;
-            let rety = match rety {
-                Some(rety) => rety.evaluate(prj, parent)?,
-                _ => TyKind::Empty.evaluate(prj, parent)?,
-            };
-
-            let root = prj.root;
-            let id = prj.insert_anonymous_type(TypeKind::FnSig { args, rety }, || Def {
-                module: module::Module::new(root),
-                node: Node::new(Default::default(), None),
-                kind: DefKind::Type(TypeKind::FnSig { args, rety }),
-            });
-            Ok(id)
-        }
-    }
-
-    impl EvaluableTypeExpression for cl_ast::Path {
-        type Out = DefID;
-
-        fn evaluate(&self, prj: &mut Project, parent: DefID) -> Result<Self::Out, String> {
-            Path::from(self).evaluate(prj, parent)
-        }
-    }
-    impl EvaluableTypeExpression for PathPart {
-        type Out = DefID;
-        fn evaluate(&self, prj: &mut Project, parent: DefID) -> Result<Self::Out, String> {
-            match self {
-                PathPart::SuperKw => prj
-                    .parent_of(parent)
-                    .ok_or_else(|| "Attempt to get super of root".into()),
-                PathPart::SelfKw => Ok(parent),
-                PathPart::SelfTy => prj
-                    .selfty_of(parent)
-                    .ok_or_else(|| "Attempt to get Self outside a Self-able context".into()),
-                PathPart::Ident(name) => name.evaluate(prj, parent),
-            }
-        }
-    }
-    impl<'a> EvaluableTypeExpression for Path<'a> {
-        type Out = DefID;
-        fn evaluate(&self, prj: &mut Project, parent: DefID) -> Result<Self::Out, String> {
-            let (tid, vid, path) = prj.get(*self, parent).ok_or("Failed to traverse path")?;
-            if !path.is_empty() {
-                Err(format!("Could not traverse past boundary: {path}"))?;
-            }
-            match (tid, vid) {
-                (Some(ty), _) => Ok(ty),
-                (None, Some(val)) => Ok(val),
-                (None, None) => Err(format!("No type or value found at path {self}")),
-            }
-        }
-    }
-    impl<T: EvaluableTypeExpression> EvaluableTypeExpression for [T] {
-        type Out = Vec<T::Out>;
-
-        fn evaluate(&self, prj: &mut Project, parent: DefID) -> Result<Self::Out, String> {
-            let mut types = vec![];
-            for value in self {
-                types.push(value.evaluate(prj, parent)?)
-            }
-
-            Ok(types)
-        }
-    }
-    impl<T: EvaluableTypeExpression> EvaluableTypeExpression for Option<T> {
-        type Out = Option<T::Out>;
-
-        fn evaluate(&self, prj: &mut Project, parent: DefID) -> Result<Self::Out, String> {
-            Ok(match self {
-                Some(v) => Some(v.evaluate(prj, parent)?),
-                None => None,
-            })
-        }
-    }
-    impl<T: EvaluableTypeExpression> EvaluableTypeExpression for Box<T> {
-        type Out = T::Out;
-
-        fn evaluate(&self, prj: &mut Project, parent: DefID) -> Result<Self::Out, String> {
-            self.as_ref().evaluate(prj, parent)
-        }
-    }
-}

compiler/cl-typeck/src/source.rs

@@ -0,0 +1,87 @@
+//! Holds the [Source] of a definition in the AST
+
+use cl_ast::ast::*;
+use std::fmt;
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+pub enum Source<'a> {
+    Root,
+    Module(&'a Module),
+    Alias(&'a Alias),
+    Enum(&'a Enum),
+    Variant(&'a Variant),
+    Struct(&'a Struct),
+    Const(&'a Const),
+    Static(&'a Static),
+    Function(&'a Function),
+    Local(&'a Let),
+    Impl(&'a Impl),
+    Use(&'a Use),
+    Ty(&'a TyKind),
+}
+
+impl Source<'_> {
+    pub fn name(&self) -> Option<Sym> {
+        match self {
+            Source::Root => None,
+            Source::Module(v) => Some(v.name),
+            Source::Alias(v) => Some(v.to),
+            Source::Enum(v) => Some(v.name),
+            Source::Variant(v) => Some(v.name),
+            Source::Struct(v) => Some(v.name),
+            Source::Const(v) => Some(v.name),
+            Source::Static(v) => Some(v.name),
+            Source::Function(v) => Some(v.name),
+            Source::Local(_) => None,
+            Source::Impl(_) | Source::Use(_) | Source::Ty(_) => None,
+        }
+    }
+
+    /// Returns `true` if this [Source] defines a named value
+    pub fn is_named_value(&self) -> bool {
+        matches!(self, Self::Const(_) | Self::Static(_) | Self::Function(_))
+    }
+
+    /// Returns `true` if this [Source] defines a named type
+    pub fn is_named_type(&self) -> bool {
+        matches!(
+            self,
+            Self::Module(_) | Self::Alias(_) | Self::Enum(_) | Self::Struct(_)
+        )
+    }
+
+    /// Returns `true` if this [Source] refers to a [Ty] with no name
+    pub fn is_anon_type(&self) -> bool {
+        matches!(self, Self::Ty(_))
+    }
+
+    /// Returns `true` if this [Source] refers to an [Impl] block
+    pub fn is_impl(&self) -> bool {
+        matches!(self, Self::Impl(_))
+    }
+
+    /// Returns `true` if this [Source] refers to a [Use] import
+    pub fn is_use_import(&self) -> bool {
+        matches!(self, Self::Use(_))
+    }
+}
+
+impl fmt::Display for Source<'_> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Root => "🌳 root 🌳".fmt(f),
+            Self::Module(arg0) => arg0.fmt(f),
+            Self::Alias(arg0) => arg0.fmt(f),
+            Self::Enum(arg0) => arg0.fmt(f),
+            Self::Variant(arg0) => arg0.fmt(f),
+            Self::Struct(arg0) => arg0.fmt(f),
+            Self::Const(arg0) => arg0.fmt(f),
+            Self::Static(arg0) => arg0.fmt(f),
+            Self::Function(arg0) => arg0.fmt(f),
+            Self::Impl(arg0) => arg0.fmt(f),
+            Self::Use(arg0) => arg0.fmt(f),
+            Self::Ty(arg0) => arg0.fmt(f),
+            Self::Local(arg0) => arg0.fmt(f),
+        }
+    }
+}

compiler/cl-typeck/src/stage/categorize.rs

@@ -0,0 +1,229 @@
+//! Categorizes an entry in a table according to its embedded type information
+
+use crate::{
+    handle::Handle,
+    source::Source,
+    table::{NodeKind, Table},
+    type_expression::{Error as TypeEval, TypeExpression},
+    type_kind::{Adt, TypeKind},
+};
+use cl_ast::*;
+
+/// Ensures a type entry exists for the provided handle in the table
+pub fn categorize(table: &mut Table, node: Handle) -> CatResult<()> {
+    if let Some(meta) = table.meta(node) {
+        for meta @ Meta { name, kind } in meta {
+            if let ("intrinsic", MetaKind::Equals(Literal::String(s))) = (&**name, kind) {
+                let kind =
+                    TypeKind::Intrinsic(s.parse().map_err(|_| Error::BadMeta(meta.clone()))?);
+                table.set_ty(node, kind);
+                return Ok(());
+            }
+        }
+    }
+
+    let Some(source) = table.source(node) else {
+        return Ok(());
+    };
+
+    match source {
+        Source::Root => Ok(()),
+        Source::Module(_) => Ok(()),
+        Source::Alias(a) => cat_alias(table, node, a),
+        Source::Enum(e) => cat_enum(table, node, e),
+        Source::Variant(_) => Ok(()),
+        Source::Struct(s) => cat_struct(table, node, s),
+        Source::Const(c) => cat_const(table, node, c),
+        Source::Static(s) => cat_static(table, node, s),
+        Source::Function(f) => cat_function(table, node, f),
+        Source::Local(l) => cat_local(table, node, l),
+        Source::Impl(i) => cat_impl(table, node, i),
+        Source::Use(_) => Ok(()),
+        Source::Ty(ty) => ty
+            .evaluate(table, node)
+            .map_err(|e| Error::TypeEval(e, " while categorizing a type"))
+            .map(drop),
+    }
+}
+
+fn parent(table: &Table, node: Handle) -> Handle {
+    table.parent(node).copied().unwrap_or(node)
+}
+
+fn cat_alias(table: &mut Table, node: Handle, a: &Alias) -> CatResult<()> {
+    let parent = parent(table, node);
+    let kind = match &a.from {
+        Some(ty) => TypeKind::Instance(
+            ty.evaluate(table, parent)
+                .map_err(|e| Error::TypeEval(e, " while categorizing an alias"))?,
+        ),
+        None => TypeKind::Empty,
+    };
+    table.set_ty(node, kind);
+
+    Ok(())
+}
+
+fn cat_struct(table: &mut Table, node: Handle, s: &Struct) -> CatResult<()> {
+    let parent = parent(table, node);
+    let Struct { name: _, kind } = s;
+    let kind = match kind {
+        StructKind::Empty => TypeKind::Adt(Adt::UnitStruct),
+        StructKind::Tuple(types) => {
+            let mut out = vec![];
+            for ty in types {
+                out.push((Visibility::Public, ty.evaluate(table, parent)?))
+            }
+            TypeKind::Adt(Adt::TupleStruct(out))
+        }
+        StructKind::Struct(members) => {
+            let mut out = vec![];
+            for m in members {
+                out.push(cat_member(table, node, m)?)
+            }
+            TypeKind::Adt(Adt::Struct(out))
+        }
+    };
+
+    table.set_ty(node, kind);
+    Ok(())
+}
+
+fn cat_member(
+    table: &mut Table,
+    node: Handle,
+    m: &StructMember,
+) -> CatResult<(Sym, Visibility, Handle)> {
+    let StructMember { vis, name, ty } = m;
+    Ok((*name, *vis, ty.evaluate(table, node)?))
+}
+
+fn cat_enum<'a>(table: &mut Table<'a>, node: Handle, e: &'a Enum) -> CatResult<()> {
+    let Enum { name: _, kind } = e;
+    let kind = match kind {
+        EnumKind::NoVariants => TypeKind::Adt(Adt::Enum(vec![])),
+        EnumKind::Variants(variants) => {
+            let mut out_vars = vec![];
+            for v in variants {
+                out_vars.push(cat_variant(table, node, v)?)
+            }
+            TypeKind::Adt(Adt::Enum(out_vars))
+        }
+    };
+
+    table.set_ty(node, kind);
+    Ok(())
+}
+
+fn cat_variant<'a>(
+    table: &mut Table<'a>,
+    node: Handle,
+    v: &'a Variant,
+) -> CatResult<(Sym, Option<Handle>)> {
+    let parent = parent(table, node);
+    let Variant { name, kind } = v;
+    match kind {
+        VariantKind::Plain => Ok((*name, None)),
+        VariantKind::CLike(c) => todo!("enum-variant constant {c}"),
+        VariantKind::Tuple(ty) => {
+            let ty = ty
+                .evaluate(table, parent)
+                .map_err(|e| Error::TypeEval(e, " while categorizing a variant"))?;
+            Ok((*name, Some(ty)))
+        }
+        VariantKind::Struct(members) => {
+            let mut out = vec![];
+            for m in members {
+                out.push(cat_member(table, node, m)?)
+            }
+            let kind = TypeKind::Adt(Adt::Struct(out));
+
+            let mut h = node.to_entry_mut(table);
+            let mut variant = h.new_entry(NodeKind::Type);
+            variant.set_source(Source::Variant(v));
+            variant.set_ty(kind);
+            Ok((*name, Some(variant.id())))
+        }
+    }
+}
+
+fn cat_const(table: &mut Table, node: Handle, c: &Const) -> CatResult<()> {
+    let parent = parent(table, node);
+    let kind = TypeKind::Instance(
+        c.ty.evaluate(table, parent)
+            .map_err(|e| Error::TypeEval(e, " while categorizing a const"))?,
+    );
+    table.set_ty(node, kind);
+    Ok(())
+}
+
+fn cat_static(table: &mut Table, node: Handle, s: &Static) -> CatResult<()> {
+    let parent = parent(table, node);
+    let kind = TypeKind::Instance(
+        s.ty.evaluate(table, parent)
+            .map_err(|e| Error::TypeEval(e, " while categorizing a static"))?,
+    );
+    table.set_ty(node, kind);
+    Ok(())
+}
+
+fn cat_function(table: &mut Table, node: Handle, f: &Function) -> CatResult<()> {
+    let parent = parent(table, node);
+    let kind = TypeKind::Instance(
+        f.sign
+            .evaluate(table, parent)
+            .map_err(|e| Error::TypeEval(e, " while categorizing a function"))?,
+    );
+    table.set_ty(node, kind);
+    Ok(())
+}
+
+fn cat_local(table: &mut Table, node: Handle, l: &Let) -> CatResult<()> {
+    let parent = parent(table, node);
+    if let Some(ty) = &l.ty {
+        let kind = ty
+            .evaluate(table, parent)
+            .map_err(|e| Error::TypeEval(e, " while categorizing a let binding"))?;
+        table.set_ty(node, TypeKind::Instance(kind));
+    }
+    Ok(())
+}
+
+fn cat_impl(table: &mut Table, node: Handle, i: &Impl) -> CatResult<()> {
+    let parent = parent(table, node);
+    let Impl { target, body: _ } = i;
+    let target = match target {
+        ImplKind::Type(t) => t.evaluate(table, parent),
+        ImplKind::Trait { impl_trait: _, for_type: t } => t.evaluate(table, parent),
+    }?;
+
+    table.set_impl_target(node, target);
+    Ok(())
+}
+
+type CatResult<T> = Result<T, Error>;
+
+#[derive(Clone, Debug)]
+pub enum Error {
+    BadMeta(Meta),
+    Recursive(Handle),
+    TypeEval(TypeEval, &'static str),
+}
+
+impl From<TypeEval> for Error {
+    fn from(value: TypeEval) -> Self {
+        Error::TypeEval(value, "")
+    }
+}
+
+impl std::fmt::Display for Error {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Error::BadMeta(meta) => write!(f, "Unknown meta attribute: #[{meta}]"),
+            Error::Recursive(id) => {
+                write!(f, "Encountered recursive type without indirection: {id}")
+            }
+            Error::TypeEval(e, during) => write!(f, "{e}{during}"),
+        }
+    }
+}

compiler/cl-typeck/src/stage/implement.rs

@@ -0,0 +1,23 @@
+use crate::{handle::Handle, table::Table};
+
+pub fn implement(table: &mut Table) -> Vec<Handle> {
+    let pending = std::mem::take(&mut table.impls);
+    let mut errors = vec![];
+    for node in pending {
+        if let Err(e) = impl_one(table, node) {
+            errors.push(e);
+        }
+    }
+    errors
+}
+
+pub fn impl_one(table: &mut Table, node: Handle) -> Result<(), Handle> {
+    let Some(target) = table.impl_target(node) else {
+        Err(node)?
+    };
+    let Table { children, imports, .. } = table;
+    if let Some(children) = children.get(&node) {
+        imports.entry(target).or_default().extend(children);
+    }
+    Ok(())
+}

compiler/cl-typeck/src/stage/import.rs

@@ -0,0 +1,158 @@
+//! An algorithm for importing external nodes
+
+use crate::{
+    handle::Handle,
+    source::Source,
+    table::{NodeKind, Table},
+};
+use cl_ast::{PathPart, Sym, Use, UseTree};
+use core::slice;
+use std::{collections::HashSet, mem};
+
+type Seen = HashSet<Handle>;
+
+pub fn import<'a>(table: &mut Table<'a>) -> Vec<(Handle, Error<'a>)> {
+    let pending = mem::take(&mut table.uses);
+
+    let mut seen = Seen::new();
+    let mut failed = vec![];
+    for import in pending {
+        let Err(e) = import_one(table, import, &mut seen) else {
+            continue;
+        };
+        if let Error::NotFound(_, _) = e {
+            table.mark_use_item(import)
+        }
+        failed.push((import, e));
+    }
+    failed
+}
+
+fn import_one<'a>(table: &mut Table<'a>, item: Handle, seen: &mut Seen) -> UseResult<'a, ()> {
+    if !seen.insert(item) {
+        return Ok(());
+    }
+
+    let Some(NodeKind::Use) = table.kind(item) else {
+        Err(Error::ItsNoUse)?
+    };
+    let Some(&dst) = table.parent(item) else {
+        Err(Error::NoParents)?
+    };
+    let Some(code) = table.source(item) else {
+        Err(Error::NoSource)?
+    };
+    let &Source::Use(tree) = code else {
+        Err(Error::BadSource(*code))?
+    };
+    let Use { absolute, tree } = tree;
+
+    import_tree(
+        table,
+        if !absolute { dst } else { table.root() },
+        dst,
+        tree,
+        seen,
+    )
+}
+
+fn import_tree<'a>(
+    table: &mut Table<'a>,
+    src: Handle,
+    dst: Handle,
+    tree: &UseTree,
+    seen: &mut Seen,
+) -> UseResult<'a, ()> {
+    match tree {
+        UseTree::Tree(trees) => trees
+            .iter()
+            .try_for_each(|tree| import_tree(table, src, dst, tree, seen)),
+        UseTree::Path(part, rest) => {
+            let source = table
+                .nav(src, slice::from_ref(part))
+                .ok_or_else(|| Error::NotFound(src, part.clone()))?;
+            import_tree(table, source, dst, rest, seen)
+        }
+        UseTree::Alias(src_name, dst_name) => {
+            import_name(table, src, src_name, dst, dst_name, seen)
+        }
+        UseTree::Name(src_name) => import_name(table, src, src_name, dst, src_name, seen),
+        UseTree::Glob => import_glob(table, src, dst, seen),
+    }
+}
+
+fn import_glob<'a>(
+    table: &mut Table<'a>,
+    src: Handle,
+    dst: Handle,
+    seen: &mut Seen,
+) -> UseResult<'a, ()> {
+    let Table { children, imports, .. } = table;
+
+    if let Some(c) = children.get(&src) {
+        imports.entry(dst).or_default().extend(c)
+    }
+
+    import_deps(table, src, seen)?;
+
+    let Table { imports, .. } = table;
+
+    // Importing imports requires some extra work, since we can't `get_many_mut`
+    if let Some(i) = imports.get(&src) {
+        let uses: Vec<_> = i.iter().map(|(&k, &v)| (k, v)).collect();
+        imports.entry(dst).or_default().extend(uses);
+    }
+
+    Ok(())
+}
+
+fn import_name<'a>(
+    table: &mut Table<'a>,
+    src: Handle,
+    src_name: &Sym,
+    dst: Handle,
+    dst_name: &Sym,
+    seen: &mut Seen,
+) -> UseResult<'a, ()> {
+    import_deps(table, src, seen)?;
+    match table.get_by_sym(src, src_name) {
+        // TODO: check for new imports clobbering existing imports
+        Some(src_id) => table.add_import(dst, *dst_name, src_id),
+        None => Err(Error::NotFound(src, PathPart::Ident(*src_name)))?,
+    };
+    Ok(())
+}
+
+/// Imports the dependencies of this node
+fn import_deps<'a>(table: &mut Table<'a>, node: Handle, seen: &mut Seen) -> UseResult<'a, ()> {
+    if let Some(items) = table.use_items.get(&node) {
+        let out = items.clone();
+        for item in out {
+            import_one(table, item, seen)?;
+        }
+    }
+    Ok(())
+}
+
+pub type UseResult<'a, T> = Result<T, Error<'a>>;
+
+#[derive(Debug)]
+pub enum Error<'a> {
+    ItsNoUse,
+    NoParents,
+    NoSource,
+    BadSource(Source<'a>),
+    NotFound(Handle, PathPart),
+}
+
+impl std::fmt::Display for Error<'_> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Error::ItsNoUse => write!(f, "Entry is not use"),
+            Error::NoParents => write!(f, "Entry has no parents"),
+            Error::NoSource => write!(f, "Entry has no source"),
+            Error::BadSource(s) => write!(f, "Entry incorrectly marked as use item: {s}"),
+            Error::NotFound(id, part) => write!(f, "Could not traverse {id}::{part}"),
+        }
+    }
+}

compiler/cl-typeck/src/stage/infer.rs

@@ -96,7 +96,7 @@ impl Type {
     }
     /// Checks whether there are any unbound type variables in this type.
     /// ```rust
-    /// # use cl_typeck::inference::*;
+    /// # use cl_typeck::stage::infer::*;
     /// let bool = Type::new_op("bool".into(), &[]);
     /// let true_v = Type::new_inst(&bool);
     /// let unbound = Type::new_var();
@@ -149,7 +149,7 @@ impl Type {
     /// Panics if this type variable's instance field is already borrowed.
     /// # Examples
     /// ```rust
-    /// # use cl_typeck::inference::*;
+    /// # use cl_typeck::stage::infer::*;
     /// let t_bool = Type::new_op("bool".into(), &[]);
     /// let t_nest = Type::new_inst(&Type::new_inst(&Type::new_inst(&t_bool)));
     /// let pruned = t_nest.prune();

compiler/cl-typeck/src/stage/populate.rs

@@ -0,0 +1,167 @@
+//! The [Populator] populates entries in the sym table, including span info
+use crate::{
+    entry::EntryMut,
+    handle::Handle,
+    source::Source,
+    table::{NodeKind, Table},
+};
+use cl_ast::{ast_visitor::Visit, ItemKind, Sym};
+
+#[derive(Debug)]
+pub struct Populator<'t, 'a> {
+    inner: EntryMut<'t, 'a>,
+    name: Option<Sym>, // this is a hack to get around the Visitor interface
+}
+
+impl<'t, 'a> Populator<'t, 'a> {
+    pub fn new(table: &'t mut Table<'a>) -> Self {
+        Self { inner: table.root_entry_mut(), name: None }
+    }
+    /// Constructs a new Populator with the provided parent Handle
+    pub fn with_id(&mut self, parent: Handle) -> Populator<'_, 'a> {
+        Populator { inner: self.inner.with_id(parent), name: None }
+    }
+
+    pub fn new_entry(&mut self, kind: NodeKind) -> Populator<'_, 'a> {
+        Populator { inner: self.inner.new_entry(kind), name: None }
+    }
+
+    pub fn set_name(&mut self, name: Sym) {
+        self.name = Some(name);
+    }
+}
+
+impl<'a> Visit<'a> for Populator<'_, 'a> {
+    fn visit_item(&mut self, i: &'a cl_ast::Item) {
+        let cl_ast::Item { extents, attrs, vis, kind } = i;
+        // TODO: this, better, better.
+        let entry_kind = match kind {
+            ItemKind::Alias(_) => NodeKind::Type,
+            ItemKind::Enum(_) => NodeKind::Type,
+            ItemKind::Struct(_) => NodeKind::Type,
+
+            ItemKind::Const(_) => NodeKind::Const,
+            ItemKind::Static(_) => NodeKind::Static,
+            ItemKind::Function(_) => NodeKind::Function,
+
+            ItemKind::Module(_) => NodeKind::Module,
+            ItemKind::Impl(_) => NodeKind::Impl,
+            ItemKind::Use(_) => NodeKind::Use,
+        };
+
+        let mut entry = self.new_entry(entry_kind);
+        entry.inner.set_span(*extents);
+        entry.inner.set_meta(&attrs.meta);
+
+        entry.visit_span(extents);
+        entry.visit_attrs(attrs);
+        entry.visit_visibility(vis);
+        entry.visit_item_kind(kind);
+
+        if let (Some(name), child) = (entry.name, entry.inner.id()) {
+            self.inner.add_child(name, child);
+        }
+    }
+
+    fn visit_alias(&mut self, a: &'a cl_ast::Alias) {
+        let cl_ast::Alias { to, from } = a;
+        self.inner.set_source(Source::Alias(a));
+        self.set_name(*to);
+
+        if let Some(t) = from {
+            self.visit_ty(t)
+        }
+    }
+
+    fn visit_const(&mut self, c: &'a cl_ast::Const) {
+        let cl_ast::Const { name, ty, init } = c;
+        self.inner.set_source(Source::Const(c));
+        self.set_name(*name);
+
+        self.visit_ty(ty);
+        self.visit_expr(init);
+    }
+
+    fn visit_static(&mut self, s: &'a cl_ast::Static) {
+        let cl_ast::Static { mutable, name, ty, init } = s;
+        self.inner.set_source(Source::Static(s));
+        self.set_name(*name);
+
+        self.visit_mutability(mutable);
+        self.visit_ty(ty);
+        self.visit_expr(init);
+    }
+
+    fn visit_module(&mut self, m: &'a cl_ast::Module) {
+        let cl_ast::Module { name, kind } = m;
+        self.inner.set_source(Source::Module(m));
+        self.set_name(*name);
+
+        self.visit_module_kind(kind);
+    }
+
+    fn visit_function(&mut self, f: &'a cl_ast::Function) {
+        let cl_ast::Function { name, sign, bind, body } = f;
+        self.inner.set_source(Source::Function(f));
+        self.set_name(*name);
+
+        self.visit_ty_fn(sign);
+        bind.iter().for_each(|p| self.visit_param(p));
+        if let Some(b) = body {
+            self.visit_block(b)
+        }
+    }
+
+    fn visit_struct(&mut self, s: &'a cl_ast::Struct) {
+        let cl_ast::Struct { name, kind } = s;
+        self.inner.set_source(Source::Struct(s));
+        self.set_name(*name);
+
+        self.visit_struct_kind(kind);
+    }
+
+    fn visit_enum(&mut self, e: &'a cl_ast::Enum) {
+        let cl_ast::Enum { name, kind } = e;
+        self.inner.set_source(Source::Enum(e));
+        self.set_name(*name);
+
+        self.visit_enum_kind(kind);
+    }
+
+    fn visit_impl(&mut self, i: &'a cl_ast::Impl) {
+        let cl_ast::Impl { target, body } = i;
+        self.inner.set_source(Source::Impl(i));
+        self.inner.mark_impl_item();
+
+        self.visit_impl_kind(target);
+        self.visit_file(body);
+    }
+
+    fn visit_use(&mut self, u: &'a cl_ast::Use) {
+        let cl_ast::Use { absolute: _, tree } = u;
+        self.inner.set_source(Source::Use(u));
+        self.inner.mark_use_item();
+
+        self.visit_use_tree(tree);
+    }
+
+    fn visit_let(&mut self, l: &'a cl_ast::Let) {
+        let cl_ast::Let { mutable, name: _, ty, init } = l;
+        let mut entry = self.new_entry(NodeKind::Local);
+
+        entry.inner.set_source(Source::Local(l));
+        // entry.set_name(*name);
+
+        entry.visit_mutability(mutable);
+        if let Some(ty) = ty {
+            entry.visit_ty(ty);
+        }
+        if let Some(init) = init {
+            entry.visit_expr(init)
+        }
+
+        // let child = entry.inner.id();
+        // self.inner.add_child(*name, child);
+        todo!("Pattern destructuring in cl-typeck")
+    }
+}

compiler/cl-typeck/src/table.rs

@@ -0,0 +1,308 @@
+//! The [Table] is a monolithic data structure representing everything the type checker
+//! knows about a program.
+//!
+//! Individual nodes in the table can be queried using the [Entry] API ([Table::entry])
+//! or modified using the [EntryMut] API ([Table::entry_mut]).
+//!
+//! # Contents of a "node"
+//! Always present:
+//! - [NodeKind]: Determines how this node will be treated during the [stages](crate::stage) of
+//!   compilation
+//! - [Parent node](Handle): Arranges this node in the hierarchical graph structure
+//!
+//! Populated as needed:
+//! - Children: An associative array of [names](Sym) to child nodes in the graph. Child nodes are
+//!   arranged in a *strict* tree structure, with no back edges
+//! - Imports: An associative array of [names](Sym) to other nodes in the graph. Not all import
+//!   nodes are back edges, but all back edges *must be* import nodes.
+//! - [Types](TypeKind): Contains type information populated through type checking and inference.
+//!   Nodes with unpopulated types may be considered type variables in the future.
+//! - [Spans][span]: Positional information from the source text. See [cl_structures::span].
+//! - [Metas](Meta): Metadata decorators. These may have an effect throughout the compiler.
+//! - [Sources](Source): Pointers back into the AST, for future analysis.
+//! - Impl Targets: Sparse mapping of `impl` nodes to their corresponding targets.
+//! - etc.
+//!
+//! [span]: struct@Span
+
+use crate::{
+    entry::{Entry, EntryMut},
+    handle::Handle,
+    source::Source,
+    type_kind::TypeKind,
+};
+use cl_ast::{Meta, PathPart, Sym};
+use cl_structures::{index_map::IndexMap, span::Span};
+use std::collections::HashMap;
+
+// TODO: Cycle detection external to this module
+
+/// The table is a monolithic data structure representing everything the type checker
+/// knows about a program.
+///
+/// See [module documentation](self).
+#[derive(Debug)]
+pub struct Table<'a> {
+    root: Handle,
+    /// This is the source of truth for handles
+    kinds: IndexMap<Handle, NodeKind>,
+    parents: IndexMap<Handle, Handle>,
+    pub(crate) children: HashMap<Handle, HashMap<Sym, Handle>>,
+    pub(crate) imports: HashMap<Handle, HashMap<Sym, Handle>>,
+    pub(crate) use_items: HashMap<Handle, Vec<Handle>>,
+    types: HashMap<Handle, TypeKind>,
+    spans: HashMap<Handle, Span>,
+    metas: HashMap<Handle, &'a [Meta]>,
+    sources: HashMap<Handle, Source<'a>>,
+    // code: HashMap<Handle, BasicBlock>, // TODO: lower sources
+    impl_targets: HashMap<Handle, Handle>,
+    anon_types: HashMap<TypeKind, Handle>,
+
+    // --- Queues for algorithms ---
+    pub(crate) impls: Vec<Handle>,
+    pub(crate) uses: Vec<Handle>,
+}
+
+impl<'a> Table<'a> {
+    pub fn new() -> Self {
+        let mut kinds = IndexMap::new();
+        let mut parents = IndexMap::new();
+        let root = kinds.insert(NodeKind::Root);
+        assert_eq!(root, parents.insert(root));
+
+        Self {
+            root,
+            kinds,
+            parents,
+            children: HashMap::new(),
+            imports: HashMap::new(),
+            use_items: HashMap::new(),
+            types: HashMap::new(),
+            spans: HashMap::new(),
+            metas: HashMap::new(),
+            sources: HashMap::new(),
+            impl_targets: HashMap::new(),
+            anon_types: HashMap::new(),
+            impls: Vec::new(),
+            uses: Vec::new(),
+        }
+    }
+
+    pub fn entry(&self, handle: Handle) -> Entry<'_, 'a> {
+        handle.to_entry(self)
+    }
+
+    pub fn entry_mut(&mut self, handle: Handle) -> EntryMut<'_, 'a> {
+        handle.to_entry_mut(self)
+    }
+
+    pub fn new_entry(&mut self, parent: Handle, kind: NodeKind) -> Handle {
+        let entry = self.kinds.insert(kind);
+        assert_eq!(entry, self.parents.insert(parent));
+        entry
+    }
+
+    pub fn add_child(&mut self, parent: Handle, name: Sym, child: Handle) -> Option<Handle> {
+        self.children.entry(parent).or_default().insert(name, child)
+    }
+
+    pub fn add_import(&mut self, parent: Handle, name: Sym, import: Handle) -> Option<Handle> {
+        self.imports.entry(parent).or_default().insert(name, import)
+    }
+
+    pub fn mark_use_item(&mut self, item: Handle) {
+        let parent = self.parents[item];
+        self.use_items.entry(parent).or_default().push(item);
+        self.uses.push(item);
+    }
+
+    pub fn mark_impl_item(&mut self, item: Handle) {
+        self.impls.push(item);
+    }
+
+    pub fn handle_iter(&mut self) -> impl Iterator<Item = Handle> {
+        self.kinds.keys()
+    }
+
+    /// Returns handles to all nodes sequentially by [Entry]
+    pub fn debug_entry_iter(&self) -> impl Iterator<Item = Entry<'_, 'a>> {
+        self.kinds.keys().map(|key| key.to_entry(self))
+    }
+
+    /// Gets the [Handle] of an anonymous type with the provided [TypeKind].
+    /// If not already present, a new one is created.
+    pub(crate) fn anon_type(&mut self, kind: TypeKind) -> Handle {
+        if let Some(id) = self.anon_types.get(&kind) {
+            return *id;
+        }
+        let entry = self.new_entry(self.root, NodeKind::Type);
+        // Anonymous types require a bijective map (anon_types => Def => types)
+        self.types.insert(entry, kind.clone());
+        self.anon_types.insert(kind, entry);
+        entry
+    }
+
+    pub const fn root_entry(&self) -> Entry<'_, 'a> {
+        self.root.to_entry(self)
+    }
+
+    pub fn root_entry_mut(&mut self) -> crate::entry::EntryMut<'_, 'a> {
+        self.root.to_entry_mut(self)
+    }
+
+    // --- inherent properties ---
+
+    pub const fn root(&self) -> Handle {
+        self.root
+    }
+
+    pub fn kind(&self, node: Handle) -> Option<&NodeKind> {
+        self.kinds.get(node)
+    }
+
+    pub fn parent(&self, node: Handle) -> Option<&Handle> {
+        self.parents.get(node)
+    }
+
+    pub fn children(&self, node: Handle) -> Option<&HashMap<Sym, Handle>> {
+        self.children.get(&node)
+    }
+
+    pub fn imports(&self, node: Handle) -> Option<&HashMap<Sym, Handle>> {
+        self.imports.get(&node)
+    }
+
+    pub fn ty(&self, node: Handle) -> Option<&TypeKind> {
+        self.types.get(&node)
+    }
+
+    pub fn span(&self, node: Handle) -> Option<&Span> {
+        self.spans.get(&node)
+    }
+
+    pub fn meta(&self, node: Handle) -> Option<&'a [Meta]> {
+        self.metas.get(&node).copied()
+    }
+
+    pub fn source(&self, node: Handle) -> Option<&Source<'a>> {
+        self.sources.get(&node)
+    }
+
+    pub fn impl_target(&self, node: Handle) -> Option<Handle> {
+        self.impl_targets.get(&node).copied()
+    }
+
+    pub fn set_ty(&mut self, node: Handle, kind: TypeKind) -> Option<TypeKind> {
+        self.types.insert(node, kind)
+    }
+
+    pub fn set_span(&mut self, node: Handle, span: Span) -> Option<Span> {
+        self.spans.insert(node, span)
+    }
+
+    pub fn set_meta(&mut self, node: Handle, meta: &'a [Meta]) -> Option<&'a [Meta]> {
+        self.metas.insert(node, meta)
+    }
+
+    pub fn set_source(&mut self, node: Handle, source: Source<'a>) -> Option<Source<'a>> {
+        self.sources.insert(node, source)
+    }
+
+    pub fn set_impl_target(&mut self, node: Handle, target: Handle) -> Option<Handle> {
+        self.impl_targets.insert(node, target)
+    }
+
+    // --- derived properties ---
+
+    /// Gets a handle to the local `Self` type, if one exists
+    pub fn selfty(&self, node: Handle) -> Option<Handle> {
+        match self.kinds.get(node)? {
+            NodeKind::Root | NodeKind::Use => None,
+            NodeKind::Type => Some(node),
+            NodeKind::Impl => self.impl_target(node),
+            _ => self.selfty(*self.parent(node)?),
+        }
+    }
+
+    pub fn name(&self, node: Handle) -> Option<Sym> {
+        self.source(node).and_then(|s| s.name())
+    }
+
+    pub fn is_transparent(&self, node: Handle) -> bool {
+        !matches!(
+            self.kind(node),
+            None | Some(NodeKind::Root | NodeKind::Module)
+        )
+    }
+
+    pub fn get_child(&self, node: Handle, name: &Sym) -> Option<Handle> {
+        self.children.get(&node).and_then(|c| c.get(name)).copied()
+    }
+
+    pub fn get_import(&self, node: Handle, name: &Sym) -> Option<Handle> {
+        self.imports.get(&node).and_then(|i| i.get(name)).copied()
+    }
+
+    pub fn get_by_sym(&self, node: Handle, name: &Sym) -> Option<Handle> {
+        self.get_child(node, name)
+            .or_else(|| self.get_import(node, name))
+            .or_else(|| {
+                self.is_transparent(node)
+                    .then(|| {
+                        self.parent(node)
+                            .and_then(|node| self.get_by_sym(*node, name))
+                    })
+                    .flatten()
+            })
+    }
+
+    /// Does path traversal relative to the provided `node`.
+    pub fn nav(&self, node: Handle, path: &[PathPart]) -> Option<Handle> {
+        match path {
+            [PathPart::SuperKw, rest @ ..] => self.nav(*self.parent(node)?, rest),
+            [PathPart::SelfKw, rest @ ..] => self.nav(node, rest),
+            [PathPart::SelfTy, rest @ ..] => self.nav(self.selfty(node)?, rest),
+            [PathPart::Ident(name), rest @ ..] => self.nav(self.get_by_sym(node, name)?, rest),
+            [] => Some(node),
+        }
+    }
+}
+
+impl Default for Table<'_> {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+#[derive(Clone, Copy, Debug)]
+pub enum NodeKind {
+    Root,
+    Module,
+    Type,
+    Const,
+    Static,
+    Function,
+    Local,
+    Impl,
+    Use,
+}
+
+mod display {
+    use super::*;
+    use std::fmt;
+    impl fmt::Display for NodeKind {
+        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+            match self {
+                NodeKind::Root => write!(f, "root"),
+                NodeKind::Module => write!(f, "mod"),
+                NodeKind::Type => write!(f, "type"),
+                NodeKind::Const => write!(f, "const"),
+                NodeKind::Static => write!(f, "static"),
+                NodeKind::Function => write!(f, "fn"),
+                NodeKind::Local => write!(f, "local"),
+                NodeKind::Use => write!(f, "use"),
+                NodeKind::Impl => write!(f, "impl"),
+            }
+        }
+    }
+}

compiler/cl-typeck/src/type_expression.rs

@@ -0,0 +1,131 @@
+//! A [TypeExpression] is a [syntactic](cl_ast) representation of a [TypeKind], and is used to
+//! construct type bindings in a [Table]'s typing context.
+
+use crate::{handle::Handle, table::Table, type_kind::TypeKind};
+use cl_ast::{PathPart, Ty, TyArray, TyFn, TyKind, TyRef, TySlice, TyTuple};
+
+#[derive(Clone, Debug, PartialEq, Eq)] // TODO: impl Display and Error
+pub enum Error {
+    BadPath { parent: Handle, path: Vec<PathPart> },
+}
+
+impl std::error::Error for Error {}
+impl std::fmt::Display for Error {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Error::BadPath { parent, path } => {
+                write!(f, "No item at path {parent}")?;
+                for part in path {
+                    write!(f, "::{part}")?;
+                }
+            }
+        }
+        Ok(())
+    }
+}
+
+/// A [TypeExpression] is a syntactic representation of a [TypeKind], and is used to construct
+/// type bindings in a [Table]'s typing context.
+pub trait TypeExpression<Out = Handle> {
+    /// Evaluates a type expression, recursively creating intermediate bindings.
+    fn evaluate(&self, table: &mut Table, node: Handle) -> Result<Out, Error>;
+}
+
+impl TypeExpression for Ty {
+    fn evaluate(&self, table: &mut Table, node: Handle) -> Result<Handle, Error> {
+        self.kind.evaluate(table, node)
+    }
+}
+
+impl TypeExpression for TyKind {
+    fn evaluate(&self, table: &mut Table, node: Handle) -> Result<Handle, Error> {
+        match self {
+            TyKind::Never => Ok(table.anon_type(TypeKind::Never)),
+            TyKind::Empty => Ok(table.anon_type(TypeKind::Empty)),
+            TyKind::Path(p) => p.evaluate(table, node),
+            TyKind::Array(a) => a.evaluate(table, node),
+            TyKind::Slice(s) => s.evaluate(table, node),
+            TyKind::Tuple(t) => t.evaluate(table, node),
+            TyKind::Ref(r) => r.evaluate(table, node),
+            TyKind::Fn(f) => f.evaluate(table, node),
+        }
+    }
+}
+
+impl TypeExpression for cl_ast::Path {
+    fn evaluate(&self, table: &mut Table, node: Handle) -> Result<Handle, Error> {
+        let Self { absolute, parts } = self;
+        parts.evaluate(table, if *absolute { table.root() } else { node })
+    }
+}
+
+impl TypeExpression for [PathPart] {
+    fn evaluate(&self, table: &mut Table, node: Handle) -> Result<Handle, Error> {
+        table
+            .nav(node, self)
+            .ok_or_else(|| Error::BadPath { parent: node, path: self.to_owned() })
+    }
+}
+
+impl TypeExpression for TyArray {
+    fn evaluate(&self, table: &mut Table, node: Handle) -> Result<Handle, Error> {
+        let Self { ty, count } = self;
+        let kind = TypeKind::Array(ty.evaluate(table, node)?, *count);
+        Ok(table.anon_type(kind))
+    }
+}
+
+impl TypeExpression for TySlice {
+    fn evaluate(&self, table: &mut Table, node: Handle) -> Result<Handle, Error> {
+        let Self { ty } = self;
+        let kind = TypeKind::Slice(ty.evaluate(table, node)?);
+        Ok(table.anon_type(kind))
+    }
+}
+
+impl TypeExpression for TyTuple {
+    fn evaluate(&self, table: &mut Table, node: Handle) -> Result<Handle, Error> {
+        let Self { types } = self;
+        let kind = match types.len() {
+            0 => TypeKind::Empty,
+            _ => TypeKind::Tuple(types.evaluate(table, node)?),
+        };
+        Ok(table.anon_type(kind))
+    }
+}
+
+impl TypeExpression for TyRef {
+    fn evaluate(&self, table: &mut Table, node: Handle) -> Result<Handle, Error> {
+        let Self { mutable: _, count, to } = self;
+        let mut t = to.evaluate(table, node)?;
+        for _ in 0..*count {
+            let kind = TypeKind::Ref(t);
+            t = table.anon_type(kind)
+        }
+        Ok(t)
+    }
+}
+
+impl TypeExpression for TyFn {
+    fn evaluate(&self, table: &mut Table, node: Handle) -> Result<Handle, Error> {
+        let Self { args, rety } = self;
+        let kind = TypeKind::FnSig {
+            args: args.evaluate(table, node)?,
+            rety: match rety {
+                Some(ty) => ty.evaluate(table, node)?,
+                None => TyKind::Empty.evaluate(table, node)?,
+            },
+        };
+        Ok(table.anon_type(kind))
+    }
+}
+
+impl<T: TypeExpression<U>, U> TypeExpression<Vec<U>> for [T] {
+    fn evaluate(&self, table: &mut Table, node: Handle) -> Result<Vec<U>, Error> {
+        let mut out = Vec::with_capacity(self.len());
+        for te in self {
+            out.push(te.evaluate(table, node)?) // try_collect is unstable
+        }
+        Ok(out)
+    }
+}

compiler/cl-typeck/src/type_kind.rs

@@ -0,0 +1,97 @@
+//! A [TypeKind] is a node in the [Table](crate::table::Table)'s type graph
+
+use crate::handle::Handle;
+use cl_ast::{Sym, Visibility};
+use std::{fmt::Debug, str::FromStr};
+
+mod display;
+
+/// A [TypeKind] represents an item
+/// (a component of a [Table](crate::table::Table))
+#[derive(Clone, Debug, PartialEq, Eq, Hash)]
+pub enum TypeKind {
+    /// An alias for an already-defined type
+    Instance(Handle),
+    /// A primitive type, built-in to the compiler
+    Intrinsic(Intrinsic),
+    /// A user-defined aromatic data type
+    Adt(Adt),
+    /// A reference to an already-defined type: &T
+    Ref(Handle),
+    /// A contiguous view of dynamically sized memory
+    Slice(Handle),
+    /// A contiguous view of statically sized memory
+    Array(Handle, usize),
+    /// A tuple of existing types
+    Tuple(Vec<Handle>),
+    /// A function which accepts multiple inputs and produces an output
+    FnSig { args: Handle, rety: Handle },
+    /// The unit type
+    Empty,
+    /// The never type
+    Never,
+    /// An untyped module
+    Module,
+}
+
+/// A user-defined Aromatic Data Type
+#[derive(Clone, Debug, PartialEq, Eq, Hash)]
+pub enum Adt {
+    /// A union-like enum type
+    Enum(Vec<(Sym, Option<Handle>)>),
+
+    /// A structural product type with named members
+    Struct(Vec<(Sym, Visibility, Handle)>),
+    /// A structural product type with unnamed members
+    TupleStruct(Vec<(Visibility, Handle)>),
+    /// A structural product type of neither named nor unnamed members
+    UnitStruct,
+
+    /// A choose your own undefined behavior type
+    /// TODO: should unions be a language feature?
+    Union(Vec<(Sym, Handle)>),
+}
+
+/// The set of compiler-intrinsic types.
+/// These primitive types have native implementations of the basic operations.
+#[rustfmt::skip]
+#[derive(Clone, Debug, PartialEq, Eq, Hash)]
+pub enum Intrinsic {
+    I8, I16, I32, I64, I128, Isize, // Signed integers
+    U8, U16, U32, U64, U128, Usize, // Unsigned integers
+    F8, F16, F32, F64, F128, Fsize, // Floating point numbers
+    Bool,                           // boolean value
+    Char,                           // Unicode codepoint
+}
+
+// Author's note: the fsize type is a meme
+
+impl FromStr for Intrinsic {
+    type Err = ();
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        Ok(match s {
+            "i8" => Intrinsic::I8,
+            "i16" => Intrinsic::I16,
+            "i32" => Intrinsic::I32,
+            "i64" => Intrinsic::I64,
+            "i128" => Intrinsic::I128,
+            "isize" => Intrinsic::Isize,
+            "u8" => Intrinsic::U8,
+            "u16" => Intrinsic::U16,
+            "u32" => Intrinsic::U32,
+            "u64" => Intrinsic::U64,
+            "u128" => Intrinsic::U128,
+            "usize" => Intrinsic::Usize,
+            "f8" => Intrinsic::F8,
+            "f16" => Intrinsic::F16,
+            "f32" => Intrinsic::F32,
+            "f64" => Intrinsic::F64,
+            "f128" => Intrinsic::F128,
+            "fsize" => Intrinsic::Fsize,
+            "bool" => Intrinsic::Bool,
+            "char" => Intrinsic::Char,
+            _ => Err(())?,
+        })
+    }
+}

compiler/cl-typeck/src/type_kind/display.rs

@@ -1,68 +1,17 @@
 //! [Display] implementations for [TypeKind], [Adt], and [Intrinsic]
 
-use super::{Adt, Def, DefKind, Intrinsic, TypeKind, ValueKind};
-use crate::{format_utils::*, node::Node};
+use super::{Adt, Intrinsic, TypeKind};
+use crate::format_utils::*;
 use cl_ast::format::FmtAdapter;
 use std::fmt::{self, Display, Write};
 
-impl Display for Def<'_> {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        let Self { module, node: Node { in_path: _, span: _, meta, vis, kind: source }, kind } =
-            self;
-        if !meta.is_empty() {
-            writeln!(f, "#{meta:?}")?;
-        }
-        if let Some(source) = source {
-            if let Some(name) = source.name() {
-                writeln!(f, "{vis}{name}:")?;
-            }
-            writeln!(f.indent(), "source:\n{source}")?;
-        } else {
-            writeln!(f, "{vis}: ")?;
-        }
-        writeln!(f, "kind: {kind}")?;
-        write!(f, "module: {module}")
-    }
-}
-
-impl Display for DefKind {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        match self {
-            DefKind::Undecided => write!(f, "undecided"),
-            DefKind::Impl(id) => write!(f, "impl {id}"),
-            DefKind::Use(id) => write!(f, "use (inside {id})"),
-            DefKind::Type(kind) => write!(f, "{kind}"),
-            DefKind::Value(kind) => write!(f, "{kind}"),
-        }
-    }
-}
-
-impl std::fmt::Display for ValueKind {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        match self {
-            ValueKind::Const(id) => write!(f, "const ({id})"),
-            ValueKind::Static(id) => write!(f, "static ({id})"),
-            ValueKind::Local(id) => write!(f, "let ({id})"),
-            ValueKind::Fn(id) => write!(f, "fn def ({id})"),
-        }
-    }
-}
-
 impl Display for TypeKind {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {
-            TypeKind::Alias(def) => match def {
-                Some(def) => write!(f, "alias to #{def}"),
-                None => f.write_str("type"),
-            },
+            TypeKind::Instance(def) => write!(f, "alias to #{def}"),
             TypeKind::Intrinsic(i) => i.fmt(f),
             TypeKind::Adt(a) => a.fmt(f),
-            TypeKind::Ref(cnt, def) => {
-                for _ in 0..*cnt {
-                    f.write_str("&")?;
-                }
-                def.fmt(f)
-            }
+            TypeKind::Ref(def) => write!(f, "&{def}"),
             TypeKind::Slice(def) => write!(f, "slice [#{def}]"),
             TypeKind::Array(def, size) => write!(f, "array [#{def}; {size}]"),
             TypeKind::Tuple(defs) => {
@@ -93,14 +42,6 @@ impl Display for Adt {
                     })
                 })(f.delimit_with("enum {", "}"))
             }
-            Adt::CLikeEnum(variants) => {
-                let mut variants = variants.iter();
-                separate(", ", || {
-                    let (name, descrim) = variants.next()?;
-                    Some(move |f: &mut Delimit<_>| write!(f, "{name} = {descrim}"))
-                })(f.delimit_with("enum {", "}"))
-            }
-            Adt::FieldlessEnum => write!(f, "enum"),
             Adt::Struct(members) => {
                 let mut members = members.iter();
                 separate(", ", || {
@@ -134,12 +75,20 @@ impl Display for Intrinsic {
             Intrinsic::I16 => f.write_str("i16"),
             Intrinsic::I32 => f.write_str("i32"),
             Intrinsic::I64 => f.write_str("i64"),
+            Intrinsic::I128 => f.write_str("i128"),
             Intrinsic::Isize => f.write_str("isize"),
             Intrinsic::U8 => f.write_str("u8"),
             Intrinsic::U16 => f.write_str("u16"),
             Intrinsic::U32 => f.write_str("u32"),
             Intrinsic::U64 => f.write_str("u64"),
+            Intrinsic::U128 => f.write_str("u128"),
             Intrinsic::Usize => f.write_str("usize"),
+            Intrinsic::F8 => f.write_str("f8"),
+            Intrinsic::F16 => f.write_str("f16"),
+            Intrinsic::F32 => f.write_str("f32"),
+            Intrinsic::F64 => f.write_str("f64"),
+            Intrinsic::F128 => f.write_str("f128"),
+            Intrinsic::Fsize => f.write_str("fsize"),
             Intrinsic::Bool => f.write_str("bool"),
             Intrinsic::Char => f.write_str("char"),
         }

compiler/cl-typeck/src/type_resolver.rs

@@ -1,336 +0,0 @@
-//! Performs step 2 of type checking: Evaluating type definitions
-
-use crate::{
-    definition::{Adt, Def, DefKind, TypeKind, ValueKind},
-    handle::DefID,
-    node::{Node, NodeSource},
-    project::{evaluate::EvaluableTypeExpression, Project as Prj},
-};
-use cl_ast::*;
-
-/// Evaluate a single ID
-pub fn resolve(prj: &mut Prj, id: DefID) -> Result<(), &'static str> {
-    let Def { node: Node { kind: Some(source), meta, .. }, kind: DefKind::Undecided, .. } = prj[id]
-    else {
-        return Ok(());
-    };
-
-    let kind = match &source {
-        NodeSource::Root => "root",
-        NodeSource::Alias(_) => "type",
-        NodeSource::Module(_) => "mod",
-        NodeSource::Enum(_) => "enum",
-        NodeSource::Variant(_) => "variant",
-        NodeSource::Struct(_) => "struct",
-        NodeSource::Const(_) => "const",
-        NodeSource::Static(_) => "static",
-        NodeSource::Function(_) => "fn",
-        NodeSource::Impl(_) => "impl",
-        NodeSource::Use(_) => "use",
-        NodeSource::Local(_) => "let",
-        NodeSource::Ty(_) => "ty",
-    };
-    let name = prj[id].name().unwrap_or("".into());
-
-    eprintln!("Resolver: \x1b[32mEvaluating\x1b[0m \"\x1b[36m{kind} {name}\x1b[0m\" (`{id:?}`)");
-
-    for Meta { name, kind } in meta {
-        if let ("intrinsic", MetaKind::Equals(Literal::String(s))) = (&**name, kind) {
-            prj[id].kind = DefKind::Type(TypeKind::Intrinsic(
-                s.parse().map_err(|_| "Failed to parse intrinsic")?,
-            ));
-        }
-    }
-    if DefKind::Undecided == prj[id].kind {
-        prj[id].kind = source.resolve_type(prj, id)?;
-    }
-
-    eprintln!("\x1b[33m=> {}\x1b[0m", prj[id].kind);
-
-    Ok(())
-}
-
-/// Resolves a given node
-pub trait TypeResolvable<'a> {
-    /// The return type upon success
-    type Out;
-    /// Resolves type expressions within this node
-    fn resolve_type(self, prj: &mut Prj<'a>, id: DefID) -> Result<Self::Out, &'static str>;
-}
-
-impl<'a> TypeResolvable<'a> for NodeSource<'a> {
-    type Out = DefKind;
-
-    fn resolve_type(self, prj: &mut Prj<'a>, id: DefID) -> Result<Self::Out, &'static str> {
-        match self {
-            NodeSource::Root => Ok(DefKind::Type(TypeKind::Module)),
-            NodeSource::Module(v) => v.resolve_type(prj, id),
-            NodeSource::Alias(v) => v.resolve_type(prj, id),
-            NodeSource::Enum(v) => v.resolve_type(prj, id),
-            NodeSource::Variant(v) => v.resolve_type(prj, id),
-            NodeSource::Struct(v) => v.resolve_type(prj, id),
-            NodeSource::Const(v) => v.resolve_type(prj, id),
-            NodeSource::Static(v) => v.resolve_type(prj, id),
-            NodeSource::Function(v) => v.resolve_type(prj, id),
-            NodeSource::Local(v) => v.resolve_type(prj, id),
-            NodeSource::Impl(v) => v.resolve_type(prj, id),
-            NodeSource::Use(v) => v.resolve_type(prj, id),
-            NodeSource::Ty(v) => v.resolve_type(prj, id),
-        }
-    }
-}
-
-impl<'a> TypeResolvable<'a> for &'a Meta {
-    type Out = DefKind;
-
-    #[allow(unused_variables)]
-    fn resolve_type(self, prj: &mut Prj<'a>, id: DefID) -> Result<Self::Out, &'static str> {
-        let Meta { name, kind } = self;
-        match (name.as_ref(), kind) {
-            ("intrinsic", MetaKind::Equals(Literal::String(intrinsic))) => Ok(DefKind::Type(
-                TypeKind::Intrinsic(intrinsic.parse().map_err(|_| "unknown intrinsic type")?),
-            )),
-            (_, MetaKind::Plain) => Ok(DefKind::Type(TypeKind::Intrinsic(
-                name.parse().map_err(|_| "Unknown intrinsic type")?,
-            ))),
-            _ => Err("Unknown meta attribute"),
-        }
-    }
-}
-
-impl<'a> TypeResolvable<'a> for &'a Module {
-    type Out = DefKind;
-    #[allow(unused_variables)]
-    fn resolve_type(self, prj: &mut Prj<'a>, id: DefID) -> Result<Self::Out, &'static str> {
-        Ok(DefKind::Type(TypeKind::Module))
-    }
-}
-
-impl<'a> TypeResolvable<'a> for &'a Alias {
-    type Out = DefKind;
-
-    fn resolve_type(self, prj: &mut Prj<'a>, id: DefID) -> Result<Self::Out, &'static str> {
-        let parent = prj.parent_of(id).unwrap_or(id);
-        let alias = if let Some(ty) = &self.from {
-            Some(
-                ty.evaluate(prj, parent)
-                    .or_else(|_| ty.evaluate(prj, id))
-                    .map_err(|_| "Unresolved type in alias")?,
-            )
-        } else {
-            None
-        };
-
-        Ok(DefKind::Type(TypeKind::Alias(alias)))
-    }
-}
-
-impl<'a> TypeResolvable<'a> for &'a Enum {
-    type Out = DefKind;
-
-    fn resolve_type(self, prj: &mut Prj<'a>, id: DefID) -> Result<Self::Out, &'static str> {
-        let Enum { name: _, kind } = self;
-        let EnumKind::Variants(v) = kind else {
-            return Ok(DefKind::Type(TypeKind::Adt(Adt::FieldlessEnum)));
-        };
-        let mut fields = vec![];
-        for Variant { name, kind: _ } in v {
-            let id = prj[id].module.get_type(*name);
-            fields.push((*name, id))
-        }
-        Ok(DefKind::Type(TypeKind::Adt(Adt::Enum(fields))))
-    }
-}
-
-impl<'a> TypeResolvable<'a> for &'a Variant {
-    type Out = DefKind;
-
-    fn resolve_type(self, prj: &mut Prj<'a>, id: DefID) -> Result<Self::Out, &'static str> {
-        // Get the grandparent of this node, for name resolution
-        let parent = prj.parent_of(id).unwrap_or(id);
-        let grandparent = prj.parent_of(parent).unwrap_or(parent);
-        let Variant { name: _, kind } = self;
-
-        Ok(DefKind::Type(match kind {
-            VariantKind::Plain => return Ok(DefKind::Type(TypeKind::Empty)),
-            VariantKind::CLike(_) => return Ok(DefKind::Undecided),
-            VariantKind::Tuple(ty) => match &ty.kind {
-                TyKind::Empty => TypeKind::Tuple(vec![]),
-                TyKind::Tuple(TyTuple { types }) => {
-                    TypeKind::Tuple(types.evaluate(prj, grandparent).map_err(|e| {
-                        eprintln!("{e}");
-                        ""
-                    })?)
-                }
-                _ => Err("Unexpected TyKind in tuple variant")?,
-            },
-            VariantKind::Struct(members) => {
-                TypeKind::Adt(Adt::Struct(members.resolve_type(prj, parent)?))
-            }
-        }))
-    }
-}
-
-impl<'a> TypeResolvable<'a> for &'a Struct {
-    type Out = DefKind;
-    fn resolve_type(self, prj: &mut Prj<'a>, id: DefID) -> Result<Self::Out, &'static str> {
-        let parent = prj.parent_of(id).unwrap_or(id);
-        let Struct { name: _, kind } = self;
-        Ok(match kind {
-            StructKind::Empty => DefKind::Type(TypeKind::Empty),
-            StructKind::Tuple(types) => DefKind::Type(TypeKind::Adt(Adt::TupleStruct({
-                let mut out = vec![];
-                for ty in types {
-                    out.push((
-                        Visibility::Public,
-                        ty.evaluate(prj, parent)
-                            .map_err(|_| "Unresolved type in tuple-struct member")?,
-                    ));
-                }
-                out
-            }))),
-            StructKind::Struct(members) => {
-                DefKind::Type(TypeKind::Adt(Adt::Struct(members.resolve_type(prj, id)?)))
-            }
-        })
-    }
-}
-
-impl<'a> TypeResolvable<'a> for &'a StructMember {
-    type Out = (Sym, Visibility, DefID);
-
-    fn resolve_type(self, prj: &mut Prj<'a>, id: DefID) -> Result<Self::Out, &'static str> {
-        let parent = prj.parent_of(id).unwrap_or(id);
-        let StructMember { name, vis, ty } = self;
-
-        let ty = ty
-            .evaluate(prj, parent)
-            .map_err(|_| "Invalid type while resolving StructMember")?;
-
-        Ok((*name, *vis, ty))
-    }
-}
-
-impl<'a> TypeResolvable<'a> for &'a Const {
-    type Out = DefKind;
-
-    fn resolve_type(self, prj: &mut Prj<'a>, id: DefID) -> Result<Self::Out, &'static str> {
-        let Const { ty, .. } = self;
-        let ty = ty
-            .evaluate(prj, id)
-            .map_err(|_| "Invalid type while resolving const")?;
-        Ok(DefKind::Value(ValueKind::Const(ty)))
-    }
-}
-
-impl<'a> TypeResolvable<'a> for &'a Static {
-    type Out = DefKind;
-
-    fn resolve_type(self, prj: &mut Prj<'a>, id: DefID) -> Result<Self::Out, &'static str> {
-        let parent = prj.parent_of(id).unwrap_or(id);
-        let Static { ty, .. } = self;
-        let ty = ty
-            .evaluate(prj, parent)
-            .map_err(|_| "Invalid type while resolving static")?;
-        Ok(DefKind::Value(ValueKind::Static(ty)))
-    }
-}
-
-impl<'a> TypeResolvable<'a> for &'a Function {
-    type Out = DefKind;
-
-    fn resolve_type(self, prj: &mut Prj<'a>, id: DefID) -> Result<Self::Out, &'static str> {
-        let parent = prj.parent_of(id).unwrap_or(id);
-        let Function { sign, .. } = self;
-        let sign = sign
-            .evaluate(prj, parent)
-            .map_err(|_| "Invalid type in function signature")?;
-        Ok(DefKind::Value(ValueKind::Fn(sign)))
-    }
-}
-
-impl<'a> TypeResolvable<'a> for &'a Let {
-    type Out = DefKind;
-
-    #[allow(unused)]
-    fn resolve_type(self, prj: &mut Prj<'a>, id: DefID) -> Result<Self::Out, &'static str> {
-        let Let { mutable, name, ty, init } = self;
-        Ok(DefKind::Undecided)
-    }
-}
-
-impl<'a> TypeResolvable<'a> for &'a Impl {
-    type Out = DefKind;
-
-    fn resolve_type(self, prj: &mut Prj<'a>, id: DefID) -> Result<Self::Out, &'static str> {
-        let parent = prj.parent_of(id).unwrap_or(id);
-
-        let target = match &self.target {
-            ImplKind::Type(t) => t.evaluate(prj, parent),
-            ImplKind::Trait { for_type, .. } => for_type.evaluate(prj, parent),
-        }
-        .map_err(|_| "Unresolved type in impl target")?;
-
-        match prj.pool.get_many_mut([id, target]) {
-            // TODO: Better error handling
-            Err(_) => Err(concat!(
-                file!(),
-                line!(),
-                column!(),
-                "id and target are same"
-            ))?,
-            Ok([id, target]) => {
-                for (name, def) in &id.module.types {
-                    target.module.insert_type(*name, *def);
-                }
-                for (name, def) in &id.module.values {
-                    target.module.insert_value(*name, *def);
-                }
-            }
-        }
-        Ok(DefKind::Impl(target))
-    }
-}
-
-impl<'a> TypeResolvable<'a> for &'a Use {
-    type Out = DefKind;
-
-    fn resolve_type(self, prj: &mut Prj<'a>, id: DefID) -> Result<Self::Out, &'static str> {
-        todo!("Resolve types for {self} with ID {id} in {prj:?}")
-    }
-}
-
-impl<'a> TypeResolvable<'a> for &'a TyKind {
-    type Out = DefKind;
-
-    #[allow(unused)]
-    fn resolve_type(self, prj: &mut Prj<'a>, id: DefID) -> Result<Self::Out, &'static str> {
-        todo!()
-    }
-}
-
-impl<'a, T> TypeResolvable<'a> for &'a [T]
-where &'a T: TypeResolvable<'a>
-{
-    type Out = Vec<<&'a T as TypeResolvable<'a>>::Out>;
-
-    fn resolve_type(self, prj: &mut Prj<'a>, id: DefID) -> Result<Self::Out, &'static str> {
-        let mut members = vec![];
-        for member in self {
-            members.push(member.resolve_type(prj, id)?);
-        }
-        Ok(members)
-    }
-}
-
-impl<'a, T> TypeResolvable<'a> for Option<&'a T>
-where &'a T: TypeResolvable<'a>
-{
-    type Out = Option<<&'a T as TypeResolvable<'a>>::Out>;
-    fn resolve_type(self, prj: &mut Prj<'a>, id: DefID) -> Result<Self::Out, &'static str> {
-        match self {
-            Some(t) => Some(t.resolve_type(prj, id)).transpose(),
-            None => Ok(None),
-        }
-    }
-}

compiler/cl-typeck/src/use_importer.rs

@@ -1,125 +0,0 @@
-//! WIP use-item importer. This performs eager import resolution on the AST
-//!
-//! # TODOs:
-//! - [ ] Resolve imports using a graph traversal rather than linear iteration
-//! - [ ] Separate imported items from natively declared items
-//! - [ ] Separate the use-import pass from the project
-//! - [ ] Report errors in a meaningful way
-//! - [ ] Lazy import resolution using graph-edge traversal during name lookup?
-//!     - It doesn't seem to me like the imports in a given scope *can change*.
-
-#![allow(unused)]
-use std::fmt::format;
-
-use cl_ast::*;
-
-use crate::{
-    definition::{Def, DefKind},
-    handle::DefID,
-    node::NodeSource,
-    project::Project,
-};
-
-type UseResult = Result<(), String>;
-
-impl<'a> Project<'a> {
-    pub fn resolve_imports(&mut self) -> UseResult {
-        for id in self.pool.keys() {
-            self.visit_def(id)?;
-        }
-        Ok(())
-    }
-
-    pub fn visit_def(&mut self, id: DefID) -> UseResult {
-        let Def { kind, node, module } = &self.pool[id];
-        if let (DefKind::Use(parent), Some(NodeSource::Use(u))) = (kind, node.kind) {
-            println!("Importing use item {u}");
-            self.visit_use(u, *parent);
-        }
-        Ok(())
-    }
-
-    pub fn visit_use(&mut self, u: &'a Use, parent: DefID) -> UseResult {
-        let Use { absolute, tree } = u;
-
-        self.visit_use_tree(tree, parent, if *absolute { self.root } else { parent })
-    }
-
-    pub fn visit_use_tree(&mut self, tree: &'a UseTree, parent: DefID, c: DefID) -> UseResult {
-        match tree {
-            UseTree::Tree(trees) => {
-                for tree in trees {
-                    self.visit_use_tree(tree, parent, c)?;
-                }
-            }
-            UseTree::Path(part, rest) => {
-                let c = self.evaluate(part, c)?;
-                self.visit_use_tree(rest, parent, c)?;
-            }
-
-            UseTree::Name(name) => self.visit_use_leaf(name, parent, c)?,
-            UseTree::Alias(from, to) => self.visit_use_alias(from, to, parent, c)?,
-            UseTree::Glob => self.visit_use_glob(parent, c)?,
-        }
-        Ok(())
-    }
-
-    pub fn visit_use_path(&mut self) -> UseResult {
-        Ok(())
-    }
-
-    pub fn visit_use_leaf(&mut self, name: &'a Sym, parent: DefID, c: DefID) -> UseResult {
-        self.visit_use_alias(name, name, parent, c)
-    }
-
-    pub fn visit_use_alias(
-        &mut self,
-        from: &Sym,
-        name: &Sym,
-        parent: DefID,
-        c: DefID,
-    ) -> UseResult {
-        let mut imported = false;
-        let c_mod = &self[c].module;
-        let (tid, vid) = (
-            c_mod.types.get(from).copied(),
-            c_mod.values.get(from).copied(),
-        );
-        let parent = &mut self[parent].module;
-
-        if let Some(tid) = tid {
-            parent.types.insert(*name, tid);
-            imported = true;
-        }
-
-        if let Some(vid) = vid {
-            parent.values.insert(*name, vid);
-            imported = true;
-        }
-
-        if imported {
-            Ok(())
-        } else {
-            Err(format!("Identifier {name} not found in module {c}"))
-        }
-    }
-
-    pub fn visit_use_glob(&mut self, parent: DefID, c: DefID) -> UseResult {
-        // Loop over all the items in c, and add them as items in the parent
-        if parent == c {
-            return Ok(());
-        }
-        let [parent, c] = self
-            .pool
-            .get_many_mut([parent, c])
-            .expect("parent and c are not the same");
-
-        for (k, v) in &c.module.types {
-            parent.module.types.entry(*k).or_insert(*v);
-        }
-        for (k, v) in &c.module.values {
-            parent.module.values.entry(*k).or_insert(*v);
-        }
-        Ok(())
-    }
-}

grammar.ebnf

@@ -96,7 +96,9 @@ Shift       = Factor   (ShiftOp   Factor )* ;
 Factor      = Term     (FactorOp  Term   )* ;
 Term        = Unary    (TermOp    Unary  )* ;
 
-Unary       = (UnaryKind)* Member ;
+Unary       = (UnaryKind)* Cast ;
+
+Cast        = Member ("as" Ty)? ;
 
 Member      = Call (Access)* ;
 Access      = '.' (Identifier ('(' Tuple? ')')? | Literal) ;

repline/examples/repl_float.rs

@@ -0,0 +1,17 @@
+//! Demonstrates the use of [read_and()]:
+//! 
+//! The provided closure:
+//! 1. Takes a line of input (a [String])
+//! 2. Performs some calculation (using [FromStr])
+//! 3. Returns a [Result] containing a [Response] or an [Err]
+
+use repline::{prebaked::read_and, Response};
+use std::{error::Error, str::FromStr};
+
+fn main() -> Result<(), Box<dyn Error>> {
+    read_and("\x1b[33m", "  >", " ?>", |line| {
+        println!("-> {:?}", f64::from_str(line.trim())?);
+        Ok(Response::Accept)
+    })?;
+    Ok(())
+}

repline/src/editor.rs

@@ -302,7 +302,7 @@ impl<'a> Editor<'a> {
     }
 }
 
-impl<'a, 'e> IntoIterator for &'e Editor<'a> {
+impl<'e> IntoIterator for &'e Editor<'_> {
     type Item = &'e char;
     type IntoIter = std::iter::Chain<
         std::collections::vec_deque::Iter<'e, char>,
@@ -313,7 +313,7 @@ impl<'a, 'e> IntoIterator for &'e Editor<'a> {
     }
 }
 
-impl<'a> Display for Editor<'a> {
+impl Display for Editor<'_> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         use std::fmt::Write;
         for c in self.iter() {

repline/src/iter.rs

@@ -39,7 +39,7 @@ pub mod chars {
                 if cont & 0xc0 != 0x80 {
                     return None;
                 }
-                out = out << 6 | (cont & 0x3f);
+                out = (out << 6) | (cont & 0x3f);
             }
             Some(char::from_u32(out).ok_or(BadUnicode(out)))
         }

sample-code/ascii.cl

@@ -0,0 +1,48 @@
+#!/usr/bin/env -S conlang -r false
+//! Prints out the characters in the ASCII printable range
+//! and the Latin-1 supplement in the format of a hex-dump
+
+fn main () {
+    ascii()
+}
+
+fn n_digit(n: u32) -> char {
+    (if n > 9 {
+        ('a' as u32) + n - 10
+    } else {
+        ('0' as u32) + n
+    }) as char
+}
+
+fn in_range(num: u32, start: u32, end: u32) -> bool {
+    (start <= num) && (num <= end )
+}
+
+fn ascii() {
+    for row in 0..16 {
+        for col in 0..16 {
+            if col == 8 {
+                print(' ')
+            }
+            print(n_digit(row), n_digit(col), ' ')
+        }
+        print(" │")
+        for col in 0..16 {
+            print(ascii_picture(row << 4 | col))
+        }
+        println("│")
+    }
+}
+
+// Start of the C0 control pictures region
+const CO_CONTROL_PICTURES: u32 = '\u{2400}' as u32;
+
+fn ascii_picture(c: u32) -> char {
+    if c < ' ' as u32 {                 // C0
+        (CO_CONTROL_PICTURES + c) as char
+    } else if c == 127 {                // C0:DEL
+        '␡' // SYMBOL_FOR_DELETE
+    } else if c.in_range(0x7f, 0xa0) {  // C1
+        ' '
+    } else c as char
+}

sample-code/fib.cl

@@ -1,11 +1,12 @@
+#!/usr/bin/env -S conlang -r false
 // Calculate Fibonacci numbers
 
 fn main() {
     for num in 0..=30 {
-        print("fib(", num, ") = ", fib_iterative(num))
+        println("fib(", num, ") = ", fibit(num))
     }
     for num in 0..=30 {
-        print("fib(", num, ") = ", fib(num))
+        println("fib(", num, ") = ", fib(num))
     }
 }
 
@@ -17,7 +18,7 @@ fn fib(a: i64) -> i64 {
 }
 
 /// The classic iterative algorithm for fib()
-fn fib_iterative(n: i64) -> i64 {
+fn fibit(n: i64) -> i64 {
     let mut a = 0;
     let mut b = 1;
     let mut c = 1;

sample-code/fizzbuzz.cl

@@ -1,13 +1,14 @@
+#!/usr/bin/env -S conlang -r false
 // FizzBuzz, using the unstable variadic-`print` builtin
 
 fn main() {
-    fizzbuzz(10, 20)
+    fizzbuzz(0, 30)
 }
 
 // Outputs FizzBuzz for numbers between `start` and `end`, inclusive
 fn fizzbuzz(start: i128, end: i128) {
     for x in start..=end {
-        print(if x % 15 == 0 {
+        println(if x % 15 == 0 {
             "FizzBuzz"
         } else if 0 == x % 3 {
             "Fizz"

sample-code/hello.cl

@@ -1,3 +1,6 @@
+#!/usr/bin/env -S conlang -r false
+//! Prints "Hello, world!"
+
 fn main() {
-    print("Hello, world!")
+    println("Hello, world!")
 }

sample-code/hello.tp

@@ -0,0 +1,5 @@
+
+// The main function
+nasin wan () {
+    toki_linja("mi toki ale a!")
+}

sample-code/hex.cl

@@ -1,23 +1,40 @@
 //! Formats numbers in hexadecimal, octal, or binary
 mod math;
+use math::{min, count_leading_zeroes};
 
-// TODO: casting and/or conversion
-const HEX_LUT: Array = [
-    '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f',
-];
+fn as_digit(n: u32) -> char {
+    (if n > 9 {
+        n - 10 + ('a' as u32)
+    } else {
+        n + ('0' as u32)
+    }) as char
+}
+
+pub fn radix(n: i64, radix: i64) {
+    fn r_str_radix(n: i64, radix: i64) {
+        if n != 0 {
+            r_str_radix(n / radix, radix) + as_digit(n % radix)
+        } else ""
+    }
+    if n == 0 {
+        "0"
+    } else if n < 0 {
+        // TODO: breaks at i64::MIN
+        "-" + r_str_radix(-n, radix)
+    } else r_str_radix(n, radix)
+}
 
 pub fn hex(n: u64) {
     let out = "0x";
     for xd in min(count_leading_zeroes(n) / 4, 15)..16 {
-        out += HEX_LUT[(n >> (15 - xd) * 4) & 0xf]
+        out += as_digit((n >> (15 - xd) * 4) & 0xf)
     }
     out
 }
-
 pub fn oct(n: u64) {
     let out = "0o";
     for xd in min((count_leading_zeroes(n) + 2) / 3, 21)..22 {
-        out += HEX_LUT[(n >> max(63 - (3 * xd), 0)) & 7]
+        out += as_digit((n >> max(63 - (3 * xd), 0)) & 7)
     }
     out
 }
@@ -25,7 +42,7 @@ pub fn oct(n: u64) {
 pub fn bin(n: u64) {
     let out = "0b";
     for xd in min(count_leading_zeroes(n), 63)..64 {
-        out += HEX_LUT[(n >> 63 - xd) & 1]
+        out += as_digit((n >> 63 - xd) & 1)
     }
     out
 }

sample-code/letter_frequency.cl

@@ -0,0 +1,44 @@
+#!/usr/bin/env -S conlang -r false
+// Showcases `get_line` behavior by sorting stdin
+
+fn in_range(this: Ord, min: Ord, max: Ord) -> bool {
+    min < this && this < max
+}
+
+fn frequency(s: str) -> [i32; 128] {
+    let letters = [0;128];
+    for letter in s {
+        if (letter).in_range(' ', letters.len() as char) {
+            letters[(letter as i32)] += 1;
+        }
+    }
+    letters
+}
+
+fn plot_freq(freq: [i32; 128]) -> str {
+    let buf = "";
+    for idx in 0..len(freq) {
+        for n in 0..(freq[idx]) {
+            buf += idx as char;
+        }
+    }
+    buf
+}
+
+const msg: str ="letter_frequency.cl
+Computes the frequency of ascii characters in a block of text, and prints it bucket-sorted.
+Press Ctrl+D to quit.";
+
+fn main () {
+    println(msg)
+    let lines = "";
+    loop {
+        let line = get_line();
+        if line == "" { break() }
+        lines += line;
+    }
+
+    let freq = frequency(lines)
+    let plot = plot_freq(freq)
+    println(plot)
+}

sample-code/match_test.cl

@@ -0,0 +1,18 @@
+//! This is a Conlang library demonstrating `match`
+
+struct Student {
+    name: str,
+    age: i32,
+}
+
+fn Student (name: str, age: i32) -> Student {
+    Student: { name, age }
+}
+
+fn match_test(student: Student) {
+    match student {
+        Student: { name: "shark", age } => println("Found a shark of ", age, " year(s)"),
+        Student: { name, age: 22 } => println("Found a 22-year-old named ", name),
+        Student: { name, age } => println("Found someone named ", name, " of ", age, " year(s)"),
+    }
+}

sample-code/math.cl

@@ -1,9 +1,15 @@
 //! Useful math functions
 
+// FIXME:
+// These two functions shouldn't actually be polymorphic, but
+// the AST interpreter doesn't know about type annotations
+// or operator overloading.
+#[generic("T")]
 pub fn max(a: T, b: T) -> T {
     (if a < b { b } else { a })
 }
 
+#[generic("T")]
 pub fn min(a: T, b: T) -> T {
     (if a > b { b } else { a })
 }

sample-code/pona.tp

@@ -0,0 +1,10 @@
+//! toki!
+
+nasin toki_pona(nimi: linja) -> linja {
+    seme nimi {
+        "a" => "PARTICLE: Emphasis or emotion",
+        _ => "",
+    }
+}
+
+kiwen main: nasin(Linja) -> Linja = toki_pona;

sample-code/rand.cl

@@ -0,0 +1,37 @@
+//! Pseudo-random number generation using a LFSR algorithm
+
+static state: u64 = 0xdeadbeefdeadbeef;
+
+pub fn seed(seed: u64) {
+    state = seed;
+}
+
+pub fn lfsr_next() {
+    state ^= state >> 7;
+    state ^= state << 9;
+    state ^= state >> 13;
+}
+
+/// Returns a pseudorandom byte
+pub fn rand() -> u8 {
+    for _ in 0..8 {
+        lfsr_next()
+    }
+    state & 0xff
+}
+
+// Prints a maze out of diagonal box drawing characters, ['╲', '╱']
+fn mazel(width: u64, height: u64) {
+    let walls = ['\u{2571}', '\u{2572}'];
+    rand_rect(width, height, walls)
+}
+
+// Prints a rectangle with the provided walls
+fn rand_rect(width: u64, height: u64, walls: [char; 2]) {
+    for _ in 0..height {
+        for _ in 0..width {
+            print(walls[rand() % 2])
+        }
+        println()
+    }
+}

sample-code/sqrt.cl

@@ -0,0 +1,56 @@
+#!/usr/bin/env conlang-run
+//! Square root approximation, and example applications
+
+/// A really small nonzero number
+const EPSILON: f64 = 8.8541878188 / 1000000000000.0;
+
+/// Calcuates the absolute value of a number
+fn f64_abs(n: f64) -> f64 {
+    let n = n as f64
+    if n < (0.0) { -n } else { n }
+}
+
+/// Square root approximation using Newton's method
+fn sqrt(n: f64) -> f64 {
+    let n = n as f64
+    if n < 0.0 {
+        return 0.0 / 0.0 // TODO: NaN constant
+    }
+    if n == 0.0 {
+        return 0.0
+    }
+
+    let z = n
+    loop {
+        let adj = (z * z - n) / (2.0 * z)
+        z -= adj
+        if adj.f64_abs() < EPSILON {
+            break z;
+        }
+    }
+}
+
+/// Pythagorean theorem: a² + b² = c²
+fn pythag(a: f64, b: f64) -> f64 {
+    sqrt(a * a + b * b)
+}
+
+/// Quadratic formula: (-b ± √(b² - 4ac)) / 2a
+fn quadratic(a: f64, b: f64, c: f64) -> (f64, f64) {
+    let a = a as f64; let b = b as f64; let c = c as f64;
+    (
+        (-b + sqrt(b * b - 4.0 * a * c)) / 2.0 * a,
+        (-b - sqrt(b * b - 4.0 * a * c)) / 2.0 * a,
+    )
+}
+
+fn main() {
+    for i in 0..10 {
+        println("sqrt(",i,") ≅ ",sqrt(i as f64))
+    }
+    println("\nPythagorean Theorem")
+    println("Hypotenuse of ⊿(5, 12): ", pythag(5.0, 12.0))
+
+    println("\nQuadratic formula")
+    println("Roots of 10x² + 4x - 1: ", quadratic(10.0, 40, -1.0))
+}

stdlib/std.cl

@@ -1,10 +1,12 @@
 //! # The Conlang Standard Library
 
 pub mod preamble {
-    pub use super::num::*;
+    pub use super::{num::*, str::str};
 }
 
 pub mod num;
 
+pub mod str;
+
 #[cfg("test")]
 mod test;

stdlib/std/num.cl

@@ -18,6 +18,9 @@ pub type i32;
 #[intrinsic = "i64"]
 pub type i64;
 
+#[intrinsic = "i128"]
+pub type i128;
+
 #[intrinsic = "isize"]
 pub type isize;
 
@@ -33,9 +36,18 @@ pub type u32;
 #[intrinsic = "u64"]
 pub type u64;
 
+#[intrinsic = "u128"]
+pub type u128;
+
 #[intrinsic = "usize"]
 pub type usize;
 
+#[intrinsic = "f32"]
+pub type f32;
+
+#[intrinsic = "f64"]
+pub type f64;
+
 // Contains implementations for (TODO) overloaded operators on num types
 pub mod ops {
     use super::*;
@@ -226,6 +238,45 @@ pub mod ops {
         }
     }
 
+    impl u128 {
+        pub const MIN: Self = 0;
+        pub const MAX: Self = !0;
+        pub const BIT_WIDTH: u32 = 8;
+        pub fn default() -> Self {
+            0
+        }
+        pub fn mul(a: Self, b: Self) -> Self {
+            a * b
+        }
+        pub fn div(a: Self, b: Self) -> Self {
+            a / b
+        }
+        pub fn rem(a: Self, b: Self) -> Self {
+            a % b
+        }
+        pub fn add(a: Self, b: Self) -> Self {
+            a + b
+        }
+        pub fn sub(a: Self, b: Self) -> Self {
+            a - b
+        }
+        pub fn shl(a: Self, b: u32) -> Self {
+            a << b
+        }
+        pub fn shr(a: Self, b: u32) -> Self {
+            a >> b
+        }
+        pub fn and(a: Self, b: Self) -> Self {
+            a & b
+        }
+        pub fn or(a: Self, b: Self) -> Self {
+            a | b
+        }
+        pub fn xor(a: Self, b: Self) -> Self {
+            a ^ b
+        }
+    }
+
     impl usize {
         pub const MIN: Self = __march_ptr_width_unsigned_min();
         pub const MAX: Self = __march_ptr_width_unsigned_max();
@@ -421,6 +472,45 @@ pub mod ops {
         }
     }
 
+    impl i128 {
+        pub const MIN: Self = !(1 << 128);
+        pub const MAX: Self = 1 << 128;
+        pub const BIT_WIDTH: u32 = 8;
+        pub fn default() -> Self {
+            0
+        }
+        pub fn mul(a: Self, b: Self) -> Self {
+            a * b
+        }
+        pub fn div(a: Self, b: Self) -> Self {
+            a / b
+        }
+        pub fn rem(a: Self, b: Self) -> Self {
+            a % b
+        }
+        pub fn add(a: Self, b: Self) -> Self {
+            a + b
+        }
+        pub fn sub(a: Self, b: Self) -> Self {
+            a - b
+        }
+        pub fn shl(a: Self, b: u32) -> Self {
+            a << b
+        }
+        pub fn shr(a: Self, b: u32) -> Self {
+            a >> b
+        }
+        pub fn and(a: Self, b: Self) -> Self {
+            a & b
+        }
+        pub fn or(a: Self, b: Self) -> Self {
+            a | b
+        }
+        pub fn xor(a: Self, b: Self) -> Self {
+            a ^ b
+        }
+    }
+
     impl isize {
         pub const MIN: Self = __march_ptr_width_signed_min();
         pub const MAX: Self = __march_ptr_width_signed_max();

stdlib/std/str.cl

@@ -0,0 +1,4 @@
+//! TODO: give conland a string type
+use super::num::u8;
+
+type str = [u8];

stdlib/std/test.cl

@@ -27,7 +27,7 @@ enum Hodgepodge {
 
 fn noop () -> bool {
     loop if false {
-        
+
     } else break loop if false {
         
     } else break loop if false {
@@ -62,3 +62,18 @@ fn if_else() -> i32 {
     }
     // block 4
 }
+
+mod horrible_imports {
+    mod foo {
+        use super::{bar::*, baz::*};
+        struct Foo(&Foo, &Bar)
+    }
+    mod bar {
+        use super::{foo::*, baz::*};
+        struct Bar(&Foo, &Baz)
+    }
+    mod baz {
+        use super::{foo::*, bar::*};
+        struct Baz(&Foo, &Bar)
+    }
+}