Conlang v0.0.5: Pratternization

cl-token:
- Minimize data redundancy by consolidating TokenKind::Literal; TokenData::{String, Identifier}
- Rename Op to Punct

cl-ast:
- Remove ExprKind::{Member, Call} in favor of making them
'binary' operators
- Consolidate boxes (TODO: consolidate more boxes)
- Remove repetition vecs in favor of boxes (this may come with performance tradeoffs!)

cl-lexer:
- Reflect changes from cl-token

cl-interpret, cl-repl/src/examples:
- Reflect changes from cl-ast

cl-parser:
- Switch to Pratt parsing for expressions
  - TODO: Code cleanup
  - TODO: Use total ordering for Precedence instead of binding powers (that's what the binding powers are there for anyway)
- Switch functional parsers to take Punct instead of TokenKind
  - It's not like we need a `for`-separated list
- Remove `binary` macro. No longer needed with precedence climbing.
- Repurpose `operator` macro to produce both the operator and the respective Precedence
- Remove several of the smaller parser functions, since they've been consolidated into the larger `exprkind`

.gitea/issue_template/feature-proposal.md

@@ -7,7 +7,7 @@ labels:
 - enhancement
 ---
 # Feature Progress
-<!-- Describe the steps for implementing this feature in libconlang -->
+<!-- Describe the steps for implementing this feature -->
 - [ ] <!-- Step 1 of implementing a feature -->
 
 # Feature description
@@ -21,4 +21,4 @@ since it most closely matches what I'm currently aiming for
 -->
 ```rust
 
-```
+```

Cargo.toml

@@ -1,10 +1,19 @@
 [workspace]
-members = ["libconlang", "cl-repl"]
+members = [
+    "cl-repl",
+    "cl-typeck",
+    "cl-interpret",
+    "cl-structures",
+    "cl-token",
+    "cl-ast",
+    "cl-parser",
+    "cl-lexer",
+]
 resolver = "2"
 
 [workspace.package]
 repository = "https://git.soft.fish/j/Conlang"
-version = "0.0.3"
+version = "0.0.5"
 authors = ["John Breaux <j@soft.fish>"]
 edition = "2021"
 license = "MIT"

cl-ast/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "cl-ast"
+repository.workspace = true
+version.workspace = true
+authors.workspace = true
+edition.workspace = true
+license.workspace = true
+publish.workspace = true
+
+[dependencies]
+cl-structures = { path = "../cl-structures" }

cl-ast/src/ast_impl.rs

@@ -5,7 +5,10 @@ mod display {
     //! Implements [Display] for [AST](super::super) Types
     use super::*;
     pub use delimiters::*;
-    use std::fmt::{Display, Write};
+    use std::{
+        borrow::Borrow,
+        fmt::{Display, Write},
+    };
     mod delimiters {
         #![allow(dead_code)]
         #[derive(Clone, Copy, Debug)]
@@ -13,6 +16,8 @@ mod display {
             pub open: &'t str,
             pub close: &'t str,
         }
+        /// Delimits with braces decorated with spaces  `" {n"`, ..., `"\n}"`
+        pub const SPACED_BRACES: Delimiters = Delimiters { open: " {\n", close: "\n}" };
         /// Delimits with braces on separate lines `{\n`, ..., `\n}`
         pub const BRACES: Delimiters = Delimiters { open: "{\n", close: "\n}" };
         /// Delimits with parentheses on separate lines `{\n`, ..., `\n}`
@@ -190,9 +195,7 @@ mod display {
             match self {
                 StructKind::Empty => ';'.fmt(f),
                 StructKind::Tuple(v) => delimit(separate(v, ", "), INLINE_PARENS)(f),
-                StructKind::Struct(v) => {
-                    delimit(separate(v, ",\n"), Delimiters { open: " {\n", ..BRACES })(f)
-                }
+                StructKind::Struct(v) => delimit(separate(v, ",\n"), SPACED_BRACES)(f),
             }
         }
     }
@@ -211,8 +214,8 @@ mod display {
     impl Display for EnumKind {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             match self {
-                EnumKind::NoVariants => todo!(),
-                EnumKind::Variants(v) => separate(v, ", ")(f),
+                EnumKind::NoVariants => ';'.fmt(f),
+                EnumKind::Variants(v) => delimit(separate(v, ",\n"), SPACED_BRACES)(f),
             }
         }
     }
@@ -226,9 +229,9 @@ mod display {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             match self {
                 VariantKind::Plain => Ok(()),
-                VariantKind::CLike(n) => n.fmt(f),
+                VariantKind::CLike(n) => write!(f, " = {n}"),
                 VariantKind::Tuple(v) => delimit(separate(v, ", "), INLINE_PARENS)(f),
-                VariantKind::Struct(v) => delimit(separate(v, ",\n"), BRACES)(f),
+                VariantKind::Struct(v) => delimit(separate(v, ", "), INLINE_BRACES)(f),
             }
         }
     }
@@ -307,13 +310,16 @@ mod display {
 
     impl Display for Expr {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-            match &self.kind {
+            self.kind.fmt(f)
+        }
+    }
+    impl Display for ExprKind {
+        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+            match self {
                 ExprKind::Assign(v) => v.fmt(f),
                 ExprKind::Binary(v) => v.fmt(f),
                 ExprKind::Unary(v) => v.fmt(f),
                 ExprKind::Index(v) => v.fmt(f),
-                ExprKind::Call(v) => v.fmt(f),
-                ExprKind::Member(v) => v.fmt(f),
                 ExprKind::Path(v) => v.fmt(f),
                 ExprKind::Literal(v) => v.fmt(f),
                 ExprKind::Array(v) => v.fmt(f),
@@ -334,8 +340,8 @@ mod display {
     }
     impl Display for Assign {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-            let Self { head, op, tail } = self;
-            write!(f, "{head} {op} {tail}")
+            let Self { kind, parts } = self;
+            write!(f, "{} {kind} {}", parts.0, parts.1)
         }
     }
     impl Display for AssignKind {
@@ -358,12 +364,13 @@ mod display {
     }
     impl Display for Binary {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-            let Self { head, tail } = self;
-            write!(f, "{head}")?;
-            for (kind, expr) in tail {
-                write!(f, " {kind} {expr}")?;
+            let Self { kind, parts } = self;
+            let (head, tail) = parts.borrow();
+            match kind {
+                BinaryKind::Dot => write!(f, "{head}{kind}{tail}"),
+                BinaryKind::Call => write!(f, "{head}{tail}"),
+                _ => write!(f, "{head} {kind} {tail}"),
             }
-            Ok(())
         }
     }
     impl Display for BinaryKind {
@@ -391,17 +398,15 @@ mod display {
                 BinaryKind::Div => "/",
                 BinaryKind::Rem => "%",
                 BinaryKind::Dot => ".",
+                BinaryKind::Call => "()",
             }
             .fmt(f)
         }
     }
     impl Display for Unary {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-            let Self { ops: kinds, tail } = self;
-            for kind in kinds {
-                kind.fmt(f)?
-            }
-            tail.fmt(f)
+            let Self { kind, tail } = self;
+            write!(f, "{kind}{tail}")
         }
     }
     impl Display for UnaryKind {
@@ -416,29 +421,11 @@ mod display {
             .fmt(f)
         }
     }
-    impl Display for Call {
-        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-            let Self { callee, args } = self;
-            callee.fmt(f)?;
-            for args in args {
-                args.fmt(f)?;
-            }
-            Ok(())
-        }
-    }
     impl Display for Tuple {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             delimit(separate(&self.exprs, ", "), INLINE_PARENS)(f)
         }
     }
-    impl Display for Member {
-        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-            let Self { head: parent, tail: children } = self;
-            write!(f, "{parent}.")?;
-            separate(children, ".")(f)?;
-            Ok(())
-        }
-    }
     impl Display for Index {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             let Self { head, indices } = self;
@@ -449,11 +436,6 @@ mod display {
             Ok(())
         }
     }
-    impl Display for Indices {
-        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-            delimit(separate(&self.exprs, ", "), INLINE_SQUARE)(f)
-        }
-    }
     impl Display for Path {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             let Self { absolute, parts } = self;
@@ -563,107 +545,6 @@ mod display {
     }
 }
 
-pub mod format {
-    //! Code formatting for the [AST](super::super)
-
-    use std::{
-        io::{Result, Write as IoWrite},
-        ops::{Deref, DerefMut},
-    };
-
-    /// Trait which adds a function to [Writers](IoWrite) to turn them into [Prettifier]
-    pub trait Pretty {
-        /// Indents code according to the number of matched curly braces
-        fn pretty(self) -> Prettifier<'static, Self>
-        where Self: IoWrite + Sized;
-    }
-    impl<W: IoWrite> Pretty for W {
-        fn pretty(self) -> Prettifier<'static, Self>
-        where Self: IoWrite + Sized {
-            Prettifier::new(self)
-        }
-    }
-
-    pub struct Prettifier<'i, T: IoWrite> {
-        level: isize,
-        indent: &'i str,
-        writer: T,
-    }
-    impl<'i, W: IoWrite> Prettifier<'i, W> {
-        pub fn new(writer: W) -> Self {
-            Self { level: 0, indent: "    ", writer }
-        }
-        pub fn with_indent(indent: &'i str, writer: W) -> Self {
-            Self { level: 0, indent, writer }
-        }
-        pub fn indent<'scope>(&'scope mut self) -> Indent<'scope, 'i, W> {
-            Indent::new(self)
-        }
-        fn write_indentation(&mut self) -> Result<usize> {
-            let Self { level, indent, writer } = self;
-            let mut count = 0;
-            for _ in 0..*level {
-                count += writer.write(indent.as_bytes())?;
-            }
-            Ok(count)
-        }
-    }
-    impl<W: IoWrite> From<W> for Prettifier<'static, W> {
-        fn from(value: W) -> Self {
-            Self::new(value)
-        }
-    }
-    impl<'i, W: IoWrite> IoWrite for Prettifier<'i, W> {
-        fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
-            let mut size = 0;
-            for buf in buf.split_inclusive(|b| b"{}".contains(b)) {
-                match buf.last() {
-                    Some(b'{') => self.level += 1,
-                    Some(b'}') => self.level -= 1,
-                    _ => (),
-                }
-                for buf in buf.split_inclusive(|b| b'\n' == *b) {
-                    size += self.writer.write(buf)?;
-                    if let Some(b'\n') = buf.last() {
-                        self.write_indentation()?;
-                    }
-                }
-            }
-            Ok(size)
-        }
-
-        fn flush(&mut self) -> std::io::Result<()> {
-            self.writer.flush()
-        }
-    }
-
-    pub struct Indent<'scope, 'i, T: IoWrite> {
-        formatter: &'scope mut Prettifier<'i, T>,
-    }
-    impl<'s, 'i, T: IoWrite> Indent<'s, 'i, T> {
-        pub fn new(formatter: &'s mut Prettifier<'i, T>) -> Self {
-            formatter.level += 1;
-            Self { formatter }
-        }
-    }
-    impl<'s, 'i, T: IoWrite> Deref for Indent<'s, 'i, T> {
-        type Target = Prettifier<'i, T>;
-        fn deref(&self) -> &Self::Target {
-            self.formatter
-        }
-    }
-    impl<'s, 'i, T: IoWrite> DerefMut for Indent<'s, 'i, T> {
-        fn deref_mut(&mut self) -> &mut Self::Target {
-            self.formatter
-        }
-    }
-    impl<'s, 'i, T: IoWrite> Drop for Indent<'s, 'i, T> {
-        fn drop(&mut self) {
-            self.formatter.level -= 1;
-        }
-    }
-}
-
 mod convert {
     //! Converts between major enums and enum variants
     use super::*;
@@ -725,8 +606,6 @@ mod convert {
             Assign => ExprKind::Assign,
             Binary => ExprKind::Binary,
             Unary => ExprKind::Unary,
-            Call => ExprKind::Call,
-            Member => ExprKind::Member,
             Index => ExprKind::Index,
             Path => ExprKind::Path,
             Literal => ExprKind::Literal,
@@ -747,18 +626,7 @@ mod convert {
             bool => Literal::Bool,
             char => Literal::Char,
             u128 => Literal::Int,
-            &str => Literal::String,
-        }
-    }
-
-    impl From<Tuple> for Indices {
-        fn from(value: Tuple) -> Self {
-            Self { exprs: value.exprs }
-        }
-    }
-    impl From<Indices> for Tuple {
-        fn from(value: Indices) -> Self {
-            Self { exprs: value.exprs }
+            String => Literal::String,
         }
     }
 

cl-ast/src/format.rs

@@ -0,0 +1,106 @@
+use std::{
+    fmt::{Result as FmtResult, Write as FmtWrite},
+    io::{Result as IoResult, Write as IoWrite},
+};
+
+/// Trait which adds a function to [fmt Writers](FmtWrite) to turn them into [Prettifier]
+pub trait FmtPretty: FmtWrite {
+    /// Indents code according to the number of matched curly braces
+    fn pretty(self) -> Prettifier<'static, Self>
+    where Self: Sized {
+        Prettifier::new(self)
+    }
+}
+/// Trait which adds a function to [io Writers](IoWrite) to turn them into [Prettifier]
+pub trait IoPretty: IoWrite {
+    /// Indents code according to the number of matched curly braces
+    fn pretty(self) -> Prettifier<'static, Self>
+    where Self: Sized;
+}
+impl<W: FmtWrite> FmtPretty for W {}
+impl<W: IoWrite> IoPretty for W {
+    fn pretty(self) -> Prettifier<'static, Self> {
+        Prettifier::new(self)
+    }
+}
+
+/// Intercepts calls to either [std::io::Write] or [std::fmt::Write],
+/// and inserts indentation between matched parentheses
+pub struct Prettifier<'i, T: ?Sized> {
+    level: isize,
+    indent: &'i str,
+    writer: T,
+}
+
+impl<'i, W> Prettifier<'i, W> {
+    pub fn new(writer: W) -> Self {
+        Self { level: 0, indent: "    ", writer }
+    }
+    pub fn with_indent(indent: &'i str, writer: W) -> Self {
+        Self { level: 0, indent, writer }
+    }
+}
+
+impl<'i, W: FmtWrite> Prettifier<'i, W> {
+    #[inline]
+    fn fmt_write_indentation(&mut self) -> FmtResult {
+        let Self { level, indent, writer } = self;
+        for _ in 0..*level {
+            writer.write_str(indent)?;
+        }
+        Ok(())
+    }
+}
+impl<'i, W: IoWrite> Prettifier<'i, W> {
+    pub fn io_write_indentation(&mut self) -> IoResult<usize> {
+        let Self { level, indent, writer } = self;
+        let mut count = 0;
+        for _ in 0..*level {
+            count += writer.write(indent.as_bytes())?;
+        }
+        Ok(count)
+    }
+}
+
+impl<'i, W: FmtWrite> FmtWrite for Prettifier<'i, W> {
+    fn write_str(&mut self, s: &str) -> FmtResult {
+        for s in s.split_inclusive(['{', '}']) {
+            match s.as_bytes().last() {
+                Some(b'{') => self.level += 1,
+                Some(b'}') => self.level -= 1,
+                _ => (),
+            }
+            for s in s.split_inclusive('\n') {
+                self.writer.write_str(s)?;
+                if let Some(b'\n') = s.as_bytes().last() {
+                    self.fmt_write_indentation()?;
+                }
+            }
+        }
+        Ok(())
+    }
+}
+
+impl<'i, W: IoWrite> IoWrite for Prettifier<'i, W> {
+    fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
+        let mut size = 0;
+        for buf in buf.split_inclusive(|b| b"{}".contains(b)) {
+            match buf.last() {
+                Some(b'{') => self.level += 1,
+                Some(b'}') => self.level -= 1,
+                _ => (),
+            }
+            for buf in buf.split_inclusive(|b| b'\n' == *b) {
+                size += self.writer.write(buf)?;
+                if let Some(b'\n') = buf.last() {
+                    self.io_write_indentation()?;
+                }
+            }
+        }
+        Ok(size)
+    }
+
+    fn flush(&mut self) -> std::io::Result<()> {
+        self.writer.flush()
+    }
+}

cl-ast/src/lib.rs

@@ -1,5 +1,5 @@
 //! # The Abstract Syntax Tree
-//! Contains definitions of AST Nodes, to be derived by a [parser](super::parser).
+//! Contains definitions of Conlang AST Nodes.
 //!
 //! # Notable nodes
 //! - [Item] and [ItemKind]: Top-level constructs
@@ -9,10 +9,15 @@
 //!   - [AssignKind], [BinaryKind], and [UnaryKind] operators
 //! - [Ty] and [TyKind]: Type qualifiers
 //! - [Path]: Path expressions
-use crate::common::*;
+#![warn(clippy::all)]
+#![feature(decl_macro)]
+
+use cl_structures::span::*;
 
 pub mod ast_impl;
+pub mod format;
 
+/// Whether a binding ([Static] or [Let]) or reference is mutable or not
 #[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
 pub enum Mutability {
     #[default]
@@ -20,6 +25,7 @@ pub enum Mutability {
     Mut,
 }
 
+/// Whether an [Item] is visible outside of the current [Module]
 #[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
 pub enum Visibility {
     #[default]
@@ -27,23 +33,26 @@ pub enum Visibility {
     Public,
 }
 
+/// A list of [Item]s
 #[derive(Clone, Debug, Default, PartialEq, Eq)]
 pub struct File {
     pub items: Vec<Item>,
 }
 
 // Metadata decorators
-#[derive(Clone, Debug, PartialEq, Eq)]
+#[derive(Clone, Debug, Default, PartialEq, Eq)]
 pub struct Attrs {
     pub meta: Vec<Meta>,
 }
 
+/// A metadata decorator
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Meta {
     pub name: Identifier,
     pub kind: MetaKind,
 }
 
+/// Information attached to [Meta]data
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub enum MetaKind {
     Plain,
@@ -52,7 +61,7 @@ pub enum MetaKind {
 }
 
 // Items
-/// Stores an [ItemKind] and associated metadata
+/// Anything that can appear at the top level of a [File]
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Item {
     pub extents: Span,
@@ -61,36 +70,37 @@ pub struct Item {
     pub kind: ItemKind,
 }
 
-/// Stores a concrete Item
+/// What kind of [Item] is this?
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub enum ItemKind {
     // TODO: Import declaration ("use") item
     // TODO: Trait declaration ("trait") item?
+    /// A [module](Module)
+    Module(Module),
     /// A [type alias](Alias)
     Alias(Alias),
+    /// An [enumerated type](Enum), with a discriminant and optional data
+    Enum(Enum),
+    /// A [structure](Struct)
+    Struct(Struct),
     /// A [constant](Const)
     Const(Const),
     /// A [static](Static) variable
     Static(Static),
-    /// A [module](Module)
-    Module(Module),
     /// A [function definition](Function)
     Function(Function),
-    /// A [structure](Struct)
-    Struct(Struct),
-    /// An [enumerated type](Enum)
-    Enum(Enum),
     /// An [implementation](Impl)
     Impl(Impl),
 }
 
+/// An alias to another [Ty]
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Alias {
-    pub to: Box<Ty>,
+    pub to: Identifier,
     pub from: Option<Box<Ty>>,
 }
 
-/// Stores a `const` value
+/// A compile-time constant
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Const {
     pub name: Identifier,
@@ -98,7 +108,7 @@ pub struct Const {
     pub init: Box<Expr>,
 }
 
-/// Stores a `static` variable
+/// A `static` variable
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Static {
     pub mutable: Mutability,
@@ -107,20 +117,21 @@ pub struct Static {
     pub init: Box<Expr>,
 }
 
-/// Stores a collection of [Items](Item)
+/// An ordered collection of [Items](Item)
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Module {
     pub name: Identifier,
     pub kind: ModuleKind,
 }
 
+/// The contents of a [Module], if they're in the same file
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub enum ModuleKind {
     Inline(File),
     Outline,
 }
 
-/// Contains code, and the interface to that code
+/// Code, and the interface to that code
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Function {
     pub name: Identifier,
@@ -129,6 +140,7 @@ pub struct Function {
     pub rety: Option<Box<Ty>>,
 }
 
+/// A single parameter for a [Function]
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Param {
     pub mutability: Mutability,
@@ -136,12 +148,14 @@ pub struct Param {
     pub ty: Box<Ty>,
 }
 
+/// A user-defined product type
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Struct {
     pub name: Identifier,
     pub kind: StructKind,
 }
 
+/// Either a [Struct]'s [StructMember]s or tuple [Ty]pes, if present.
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub enum StructKind {
     Empty,
@@ -149,6 +163,7 @@ pub enum StructKind {
     Struct(Vec<StructMember>),
 }
 
+/// The [Visibility], [Identifier], and [Ty]pe of a single [Struct] member
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct StructMember {
     pub vis: Visibility,
@@ -156,12 +171,14 @@ pub struct StructMember {
     pub ty: Ty,
 }
 
+/// A user-defined sum type
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Enum {
     pub name: Identifier,
     pub kind: EnumKind,
 }
 
+/// An [Enum]'s [Variant]s, if it has a variant block
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub enum EnumKind {
     /// Represents an enum with no variants
@@ -169,12 +186,14 @@ pub enum EnumKind {
     Variants(Vec<Variant>),
 }
 
+/// A single [Enum] variant
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Variant {
     pub name: Identifier,
     pub kind: VariantKind,
 }
 
+/// Whether the [Variant] has a C-like constant value, a tuple, or [StructMember]s
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub enum VariantKind {
     Plain,
@@ -183,6 +202,7 @@ pub enum VariantKind {
     Struct(Vec<StructMember>),
 }
 
+/// Sub-[items](Item) (associated functions, etc.) for a [Ty]
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Impl {
     pub target: Ty,
@@ -196,13 +216,14 @@ pub enum ImplKind {
     Trait { impl_trait: Path, for_type: Box<Ty> },
 }
 
-/// # Static Type Information
+/// A type expression
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Ty {
     pub extents: Span,
     pub kind: TyKind,
 }
 
+/// Information about a [Ty]pe expression
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub enum TyKind {
     Never,
@@ -214,29 +235,34 @@ pub enum TyKind {
     Fn(TyFn),
 }
 
+/// A tuple of [Ty]pes
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct TyTuple {
     pub types: Vec<Ty>,
 }
 
+/// A [Ty]pe-reference expression as (number of `&`, [Path])
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct TyRef {
     pub count: u16,
     pub to: Path,
 }
+
+/// The args and return value for a function pointer [Ty]pe
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct TyFn {
     pub args: TyTuple,
     pub rety: Option<Box<Ty>>,
 }
 
-// Path
+/// A path to an [Item] in the [Module] tree
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Path {
     pub absolute: bool,
     pub parts: Vec<PathPart>,
 }
 
+/// A single component of a [Path]
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub enum PathPart {
     SuperKw,
@@ -245,10 +271,11 @@ pub enum PathPart {
 }
 
 // TODO: Capture token?
+/// A name
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Identifier(pub String);
 
-/// Stores an abstract statement, and associated metadata
+/// An abstract statement, and associated metadata
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Stmt {
     pub extents: Span,
@@ -256,12 +283,14 @@ pub struct Stmt {
     pub semi: Semi,
 }
 
+/// Whether or not a [Stmt] is followed by a semicolon
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub enum Semi {
     Terminated,
     Unterminated,
 }
 
+/// Whether the [Stmt] is a [Let], [Item], or [Expr] statement
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub enum StmtKind {
     Empty,
@@ -270,6 +299,7 @@ pub enum StmtKind {
     Expr(Box<Expr>),
 }
 
+/// A local variable declaration [Stmt]
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Let {
     pub mutable: Mutability,
@@ -278,25 +308,22 @@ pub struct Let {
     pub init: Option<Box<Expr>>,
 }
 
-/// Stores an abstract expression, and associated metadata
+/// An expression, the beating heart of the language
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Expr {
     pub extents: Span,
     pub kind: ExprKind,
 }
 
+/// Any of the different [Expr]essions
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub enum ExprKind {
     /// An [Assign]ment expression: [`Expr`] ([`AssignKind`] [`Expr`])\+
-    Assign(Box<Assign>),
+    Assign(Assign),
     /// A [Binary] expression: [`Expr`] ([`BinaryKind`] [`Expr`])\+
     Binary(Binary),
     /// A [Unary] expression: [`UnaryKind`]\* [`Expr`]
     Unary(Unary),
-    /// A [Member] access expression: [`Expr`] (`.` [`Expr`])+
-    Member(Member),
-    /// A [Call] expression, with arguments: a(foo, bar)
-    Call(Call),
     /// An Array [Index] expression: a[10, 20, 30]
     Index(Index),
     /// A [path expression](Path): `::`? [PathPart] (`::` [PathPart])*
@@ -332,11 +359,11 @@ pub enum ExprKind {
     Continue(Continue),
 }
 
+/// An [Assign]ment expression: [`Expr`] ([`AssignKind`] [`Expr`])\+
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Assign {
-    pub head: Expr,
-    pub op: AssignKind,
-    pub tail: Box<Expr>,
+    pub kind: AssignKind,
+    pub parts: Box<(ExprKind, ExprKind)>,
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
@@ -355,12 +382,14 @@ pub enum AssignKind {
     Rem,
 }
 
+/// A [Binary] expression: [`Expr`] ([`BinaryKind`] [`Expr`])\+
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Binary {
-    pub head: Box<Expr>,
-    pub tail: Vec<(BinaryKind, Expr)>,
+    pub kind: BinaryKind,
+    pub parts: Box<(ExprKind, ExprKind)>,
 }
 
+/// A [Binary] operator
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub enum BinaryKind {
     Lt,
@@ -385,15 +414,18 @@ pub enum BinaryKind {
     Div,
     Rem,
     Dot,
+    Call,
 }
 
+/// A [Unary] expression: [`UnaryKind`]\* [`Expr`]
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Unary {
-    pub ops: Vec<UnaryKind>,
-    pub tail: Box<Expr>,
+    pub kind: UnaryKind,
+    pub tail: Box<ExprKind>,
 }
 
-#[derive(Clone, Debug, PartialEq, Eq)]
+/// A [Unary] operator
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub enum UnaryKind {
     Deref,
     Neg,
@@ -403,36 +435,14 @@ pub enum UnaryKind {
     /// Unused
     Tilde,
 }
-
-#[derive(Clone, Debug, PartialEq, Eq)]
-pub struct Member {
-    pub head: Box<Expr>,
-    pub tail: Vec<Expr>,
-}
-
-#[derive(Clone, Debug, PartialEq, Eq)]
-pub enum MemberKind {
-    Dot,
-}
-
-#[derive(Clone, Debug, PartialEq, Eq)]
-pub struct Call {
-    pub callee: Box<Expr>,
-    pub args: Vec<Tuple>,
-}
-
-/// Index operator: Member (`[` Expr `]`)*
+/// A repeated [Index] expression: a[10, 20, 30][40, 50, 60]
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Index {
-    pub head: Box<Expr>,
-    pub indices: Vec<Indices>,
-}
-
-#[derive(Clone, Debug, PartialEq, Eq)]
-pub struct Indices {
-    pub exprs: Vec<Expr>,
+    pub head: Box<ExprKind>,
+    pub indices: Vec<Expr>,
 }
 
+/// A [Literal]: 0x42, 1e123, 2.4, "Hello"
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub enum Literal {
     Bool(bool),
@@ -441,39 +451,47 @@ pub enum Literal {
     String(String),
 }
 
+/// An [Array] literal: `[` [`Expr`] (`,` [`Expr`])\* `]`
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Array {
     pub values: Vec<Expr>,
 }
 
+/// An Array literal constructed with [repeat syntax](ArrayRep)
+/// `[` [Expr] `;` [Literal] `]`
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct ArrayRep {
-    pub value: Box<Expr>,
-    pub repeat: Box<Expr>,
+    pub value: Box<ExprKind>,
+    pub repeat: Box<ExprKind>,
 }
 
+/// An address-of expression: `&` `mut`? [`Expr`]
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct AddrOf {
     pub count: usize,
     pub mutable: Mutability,
-    pub expr: Box<Expr>,
+    pub expr: Box<ExprKind>,
 }
 
+/// A [Block] expression: `{` [`Stmt`]\* [`Expr`]? `}`
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Block {
     pub stmts: Vec<Stmt>,
 }
 
+/// A [Grouping](Group) expression `(` [`Expr`] `)`
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Group {
-    pub expr: Box<Expr>,
+    pub expr: Box<ExprKind>,
 }
 
+/// A [Tuple] expression: `(` [`Expr`] (`,` [`Expr`])+ `)`
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Tuple {
     pub exprs: Vec<Expr>,
 }
 
+/// A [While] expression: `while` [`Expr`] [`Block`] [`Else`]?
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct While {
     pub cond: Box<Expr>,
@@ -481,6 +499,7 @@ pub struct While {
     pub fail: Else,
 }
 
+/// An [If] expression: `if` [`Expr`] [`Block`] [`Else`]?
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct If {
     pub cond: Box<Expr>,
@@ -488,6 +507,7 @@ pub struct If {
     pub fail: Else,
 }
 
+/// A [For] expression: `for` Pattern `in` [`Expr`] [`Block`] [`Else`]?
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct For {
     pub bind: Identifier, // TODO: Patterns?
@@ -496,20 +516,24 @@ pub struct For {
     pub fail: Else,
 }
 
+/// The (optional) `else` clause of a [While], [If], or [For] expression
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Else {
     pub body: Option<Box<Expr>>,
 }
 
+/// A [Break] expression: `break` [`Expr`]?
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Break {
     pub body: Option<Box<Expr>>,
 }
 
+/// A [Return] expression `return` [`Expr`]?
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Return {
     pub body: Option<Box<Expr>>,
 }
 
+/// A continue expression: `continue`
 #[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
 pub struct Continue;

cl-interpret/Cargo.toml

@@ -0,0 +1,17 @@
+[package]
+name = "cl-interpret"
+repository.workspace = true
+version.workspace = true
+authors.workspace = true
+edition.workspace = true
+license.workspace = true
+publish.workspace = true
+
+[dependencies]
+cl-ast = { path = "../cl-ast" }
+cl-structures = { path = "../cl-structures" }
+
+
+[dev-dependencies]
+cl-lexer = { path = "../cl-lexer" }
+cl-parser = { path = "../cl-parser" }

cl-interpret/examples/fib.rs

@@ -0,0 +1,16 @@
+// Calculate Fibonacci numbers
+
+fn main() {
+    for num in 0..=30 {
+        println!("fib({num}) = {}", fib(num))
+    }
+}
+
+/// Implements the classic recursive definition of fib()
+fn fib(a: i64) -> i64 {
+    if a > 1 {
+        fib(a - 1) + fib(a - 2)
+    } else {
+        1
+    }
+}

cl-interpret/src/builtin.rs

@@ -0,0 +1,239 @@
+//! Implementations of built-in functions
+
+use super::{
+    env::Environment,
+    error::{Error, IResult},
+    temp_type_impl::ConValue,
+    BuiltIn, Callable,
+};
+use std::io::{stdout, Write};
+
+builtins! {
+    const MISC;
+    /// Unstable variadic print function
+    pub fn print<_, 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)
+    }
+}
+builtins! {
+    const BINARY;
+    /// Multiplication `a * b`
+    pub fn mul(lhs, rhs) -> IResult<ConValue> {
+        Ok(match (lhs, rhs) {
+            (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
+            (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a * b),
+            _ => Err(Error::TypeError)?
+        })
+    }
+    /// Division `a / b`
+    pub fn div(lhs, rhs) -> IResult<ConValue> {
+        Ok(match (lhs, rhs){
+            (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
+            (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a / b),
+            _ => Err(Error::TypeError)?
+        })
+    }
+    /// Remainder `a % b`
+    pub fn rem(lhs, rhs) -> IResult<ConValue> {
+        Ok(match (lhs, rhs) {
+            (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
+            (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a % b),
+            _ => Err(Error::TypeError)?,
+        })
+    }
+
+    /// Addition `a + b`
+    pub fn add(lhs, rhs) -> IResult<ConValue> {
+        Ok(match (lhs, rhs) {
+            (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
+            (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a + b),
+            (ConValue::String(a), ConValue::String(b)) => ConValue::String(a.to_string() + b),
+            _ => Err(Error::TypeError)?
+        })
+    }
+    /// Subtraction `a - b`
+    pub fn sub(lhs, rhs) -> IResult<ConValue> {
+        Ok(match (lhs, rhs) {
+            (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
+            (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a - b),
+            _ => Err(Error::TypeError)?,
+        })
+    }
+
+    /// Shift Left `a << b`
+    pub fn shl(lhs, rhs) -> IResult<ConValue> {
+        Ok(match (lhs, rhs) {
+            (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
+            (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a << b),
+            _ => Err(Error::TypeError)?,
+        })
+    }
+    /// Shift Right `a >> b`
+    pub fn shr(lhs, rhs) -> IResult<ConValue> {
+        Ok(match (lhs, rhs) {
+            (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
+            (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a >> b),
+            _ => Err(Error::TypeError)?,
+        })
+    }
+
+    /// Bitwise And `a & b`
+    pub fn and(lhs, rhs) -> IResult<ConValue> {
+        Ok(match (lhs, rhs) {
+            (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)?,
+        })
+    }
+    /// Bitwise Or `a | b`
+    pub fn or(lhs, rhs) -> IResult<ConValue> {
+        Ok(match (lhs, rhs) {
+            (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)?,
+        })
+    }
+    /// Bitwise Exclusive Or `a ^ b`
+    pub fn xor(lhs, rhs) -> IResult<ConValue> {
+        Ok(match (lhs, rhs) {
+            (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)?,
+        })
+    }
+
+    /// 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 {
+            Err(Error::TypeError)?
+        };
+        Ok(ConValue::RangeExc(lhs, rhs.saturating_sub(1)))
+    }
+    /// Inclusive Range `a..=b`
+    pub fn range_inc(lhs, rhs) -> IResult<ConValue> {
+        let (&ConValue::Int(lhs), &ConValue::Int(rhs)) = (lhs, rhs) else {
+            Err(Error::TypeError)?
+        };
+        Ok(ConValue::RangeInc(lhs, rhs))
+    }
+}
+builtins! {
+    const UNARY;
+    /// Negates the ConValue
+    pub fn neg(tail) -> IResult<ConValue> {
+        Ok(match tail {
+            ConValue::Empty => ConValue::Empty,
+            ConValue::Int(v) => ConValue::Int(-v),
+            _ => Err(Error::TypeError)?,
+        })
+    }
+    /// Inverts the ConValue
+    pub fn not(tail) -> IResult<ConValue> {
+        Ok(match tail {
+            ConValue::Empty => ConValue::Empty,
+            ConValue::Int(v) => ConValue::Int(!v),
+            ConValue::Bool(v) => ConValue::Bool(!v),
+            _ => Err(Error::TypeError)?,
+        })
+    }
+}
+
+/// 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)?;)?
+                $body
+            }
+            fn name(&self) -> &str { stringify!($name) }
+        }
+    )*
+}
+
+/// 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)
+    }
+}

cl-interpret/src/interpret.rs

@@ -0,0 +1,447 @@
+//! A work-in-progress tree walk interpreter for Conlang
+//!
+//! Currently, major parts of the interpreter are not yet implemented, and major parts will never be
+//! implemented in its current form. Namely, since no [ConValue] has a stable location, it's
+//! meaningless to get a pointer to one, and would be undefined behavior to dereference a pointer to
+//! one in any situation.
+
+use std::borrow::Borrow;
+
+use super::*;
+use cl_ast::*;
+/// A work-in-progress tree walk interpreter for Conlang
+pub trait Interpret {
+    /// Interprets this thing in the given [`Environment`].
+    ///
+    /// Everything returns a value!™
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue>;
+}
+
+impl Interpret for File {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        for item in &self.items {
+            item.interpret(env)?;
+        }
+        Ok(ConValue::Empty)
+    }
+}
+impl Interpret for Item {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        match &self.kind {
+            ItemKind::Alias(item) => item.interpret(env),
+            ItemKind::Const(item) => item.interpret(env),
+            ItemKind::Static(item) => item.interpret(env),
+            ItemKind::Module(item) => item.interpret(env),
+            ItemKind::Function(item) => item.interpret(env),
+            ItemKind::Struct(item) => item.interpret(env),
+            ItemKind::Enum(item) => item.interpret(env),
+            ItemKind::Impl(item) => item.interpret(env),
+        }
+    }
+}
+impl Interpret for Alias {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        todo!("Interpret type alias in {env}")
+    }
+}
+impl Interpret for Const {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        todo!("interpret const in {env}")
+    }
+}
+impl Interpret for Static {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        todo!("interpret static in {env}")
+    }
+}
+impl Interpret for Module {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        // TODO: Enter this module's namespace
+        match &self.kind {
+            ModuleKind::Inline(file) => file.interpret(env),
+            ModuleKind::Outline => todo!("Load and parse external files"),
+        }
+    }
+}
+impl Interpret for Function {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        // register the function in the current environment
+        env.insert_fn(self);
+        Ok(ConValue::Empty)
+    }
+}
+impl Interpret for Struct {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        todo!("Interpret structs in {env}")
+    }
+}
+impl Interpret for Enum {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        todo!("Interpret enums in {env}")
+    }
+}
+impl Interpret for Impl {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        todo!("Enter a struct's namespace and insert function definitions into it in {env}");
+    }
+}
+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)?,
+        };
+        Ok(match semi {
+            Semi::Terminated => ConValue::Empty,
+            Semi::Unterminated => out,
+        })
+    }
+}
+impl Interpret for Let {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        let Let { mutable: _, name: Identifier(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> {
+        let Self { extents: _, kind } = self;
+        kind.interpret(env)
+    }
+}
+impl Interpret for ExprKind {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        match self {
+            ExprKind::Assign(v) => v.interpret(env),
+            ExprKind::Binary(v) => v.interpret(env),
+            ExprKind::Unary(v) => v.interpret(env),
+            ExprKind::Index(v) => v.interpret(env),
+            ExprKind::Path(v) => v.interpret(env),
+            ExprKind::Literal(v) => v.interpret(env),
+            ExprKind::Array(v) => v.interpret(env),
+            ExprKind::ArrayRep(v) => v.interpret(env),
+            ExprKind::AddrOf(v) => v.interpret(env),
+            ExprKind::Block(v) => v.interpret(env),
+            ExprKind::Empty => Ok(ConValue::Empty),
+            ExprKind::Group(v) => v.interpret(env),
+            ExprKind::Tuple(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),
+        }
+    }
+}
+impl Interpret for Assign {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        let Assign { kind: op, parts } = self;
+        let (head, tail) = parts.borrow();
+        // Resolve the head pattern
+        let head = match &head {
+            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::Ident(Identifier(s)) => s,
+                }
+            }
+            ExprKind::Index(_) => todo!("Assignment to an index operation"),
+            ExprKind::Path(_) => todo!("Path expression resolution (IMPORTANT)"),
+            ExprKind::Empty | ExprKind::Group(_) | ExprKind::Tuple(_) => {
+                todo!("Pattern Destructuring?")
+            }
+            _ => Err(Error::NotAssignable)?,
+        };
+        // Get the initializer and the tail
+        let init = tail.interpret(env)?;
+        let target = env.get_mut(head)?;
+
+        if let AssignKind::Plain = op {
+            use std::mem::discriminant as variant;
+            // runtime typecheck
+            match target {
+                Some(value) if variant(value) == variant(&init) => {
+                    *value = init;
+                }
+                value @ None => *value = Some(init),
+                _ => Err(Error::TypeError)?,
+            }
+            return Ok(ConValue::Empty);
+        }
+        let Some(target) = target else {
+            return Err(Error::NotInitialized(head.into()));
+        };
+
+        match op {
+            AssignKind::Add => target.add_assign(init)?,
+            AssignKind::Sub => target.sub_assign(init)?,
+            AssignKind::Mul => target.mul_assign(init)?,
+            AssignKind::Div => target.div_assign(init)?,
+            AssignKind::Rem => target.rem_assign(init)?,
+            AssignKind::And => target.bitand_assign(init)?,
+            AssignKind::Or => target.bitor_assign(init)?,
+            AssignKind::Xor => target.bitxor_assign(init)?,
+            AssignKind::Shl => target.shl_assign(init)?,
+            AssignKind::Shr => target.shr_assign(init)?,
+            _ => (),
+        }
+        Ok(ConValue::Empty)
+    }
+}
+impl Interpret for Binary {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        let Binary { kind, parts } = self;
+        let (head, tail) = parts.borrow();
+
+        let head = head.interpret(env)?;
+
+        // Short-circuiting ops
+        match kind {
+            BinaryKind::LogAnd => {
+                return if head.truthy()? {
+                    tail.interpret(env)
+                } else {
+                    Ok(head)
+                }; // Short circuiting
+            }
+            BinaryKind::LogOr => {
+                return if !head.truthy()? {
+                    tail.interpret(env)
+                } else {
+                    Ok(head)
+                }; // Short circuiting
+            }
+            BinaryKind::LogXor => {
+                return Ok(ConValue::Bool(
+                    head.truthy()? ^ tail.interpret(env)?.truthy()?,
+                ));
+            }
+            _ => {}
+        }
+        let tail = tail.interpret(env)?;
+        match kind {
+            BinaryKind::Mul => env.call("mul", &[head, tail]),
+            BinaryKind::Div => env.call("div", &[head, tail]),
+            BinaryKind::Rem => env.call("rem", &[head, tail]),
+            BinaryKind::Add => env.call("add", &[head, tail]),
+            BinaryKind::Sub => env.call("sub", &[head, tail]),
+            BinaryKind::Shl => env.call("shl", &[head, tail]),
+            BinaryKind::Shr => env.call("shr", &[head, tail]),
+            BinaryKind::BitAnd => env.call("and", &[head, tail]),
+            BinaryKind::BitOr => env.call("or", &[head, tail]),
+            BinaryKind::BitXor => env.call("xor", &[head, tail]),
+            BinaryKind::RangeExc => env.call("range_exc", &[head, tail]),
+            BinaryKind::RangeInc => env.call("range_inc", &[head, tail]),
+            BinaryKind::Lt => env.call("lt", &[head, tail]),
+            BinaryKind::LtEq => env.call("lt_eq", &[head, tail]),
+            BinaryKind::Equal => env.call("eq", &[head, tail]),
+            BinaryKind::NotEq => env.call("neq", &[head, tail]),
+            BinaryKind::GtEq => env.call("gt_eq", &[head, tail]),
+            BinaryKind::Gt => env.call("gt", &[head, tail]),
+            BinaryKind::Dot => todo!("search within a type's namespace!"),
+            BinaryKind::Call => match tail {
+                ConValue::Empty => head.call(env, &[]),
+                ConValue::Tuple(args) => head.call(env, &args),
+                _ => Err(Error::TypeError),
+            },
+            _ => Ok(head),
+        }
+    }
+}
+
+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", &[operand]),
+            UnaryKind::Neg => env.call("neg", &[operand]),
+            UnaryKind::Not => env.call("not", &[operand]),
+            UnaryKind::At => {
+                println!("{operand}");
+                Ok(operand)
+            }
+            UnaryKind::Tilde => unimplemented!("Tilde operator"),
+        }
+    }
+}
+impl Interpret for Index {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        let Self { head, indices } = self;
+        let mut head = head.interpret(env)?;
+        for index in indices {
+            head = head.index(&index.interpret(env)?)?;
+        }
+        Ok(head)
+    }
+}
+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::Ident(Identifier(s)) => env.get(s).cloned(),
+            }
+        } else {
+            todo!("Path navigation!")
+        }
+    }
+}
+impl Interpret for Literal {
+    fn interpret(&self, _env: &mut Environment) -> IResult<ConValue> {
+        Ok(match self {
+            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::Int(value) => ConValue::Int(*value as _),
+        })
+    }
+}
+impl Interpret for Array {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        let Self { values } = self;
+        let mut out = vec![];
+        for expr in values {
+            out.push(expr.interpret(env)?)
+        }
+        Ok(ConValue::Array(out))
+    }
+}
+impl Interpret for ArrayRep {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        let Self { value, repeat } = self;
+        let repeat = match repeat.interpret(env)? {
+            ConValue::Int(v) => v,
+            _ => Err(Error::TypeError)?,
+        };
+        let value = value.interpret(env)?;
+        Ok(ConValue::Array(vec![value; repeat as usize]))
+    }
+}
+impl Interpret for AddrOf {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        let Self { count: _, mutable: _, expr } = self;
+        // this is stupid
+        todo!("Create reference\nfrom expr: {expr}\nin env:\n{env}\n")
+    }
+}
+impl Interpret for Block {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        let Self { stmts } = self;
+        let mut env = env.frame("block");
+        let mut out = ConValue::Empty;
+        for stmt in stmts {
+            out = stmt.interpret(&mut env)?;
+        }
+        Ok(out)
+    }
+}
+impl Interpret for Group {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        let Self { expr } = self;
+        expr.interpret(env)
+    }
+}
+impl Interpret for Tuple {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        let Self { exprs } = self;
+        Ok(ConValue::Tuple(exprs.iter().try_fold(
+            vec![],
+            |mut out, element| {
+                out.push(element.interpret(env)?);
+                Ok(out)
+            },
+        )?))
+    }
+}
+impl Interpret for While {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        let Self { cond, pass, fail } = self;
+        while cond.interpret(env)?.truthy()? {
+            match pass.interpret(env) {
+                Err(Error::Break(value)) => return Ok(value),
+                Err(Error::Continue) => continue,
+                e => e?,
+            };
+        }
+        fail.interpret(env)
+    }
+}
+impl Interpret for If {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        let Self { cond, pass, fail } = self;
+        if cond.interpret(env)?.truthy()? {
+            pass.interpret(env)
+        } else {
+            fail.interpret(env)
+        }
+    }
+}
+impl Interpret for For {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        let Self { bind: Identifier(name), cond, pass, fail } = self;
+        // TODO: A better iterator model
+        let bounds = match cond.interpret(env)? {
+            ConValue::RangeExc(a, b) => a..=b,
+            ConValue::RangeInc(a, b) => a..=b,
+            _ => Err(Error::TypeError)?,
+        };
+        {
+            let mut env = env.frame("loop variable");
+            for loop_var in bounds {
+                env.insert(name, Some(loop_var.into()));
+                match pass.interpret(&mut env) {
+                    Err(Error::Break(value)) => return Ok(value),
+                    Err(Error::Continue) => continue,
+                    result => result?,
+                };
+            }
+        }
+        fail.interpret(env)
+    }
+}
+impl Interpret for Else {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        let Self { body } = self;
+        match body {
+            Some(body) => body.interpret(env),
+            None => Ok(ConValue::Empty),
+        }
+    }
+}
+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;
+        Err(Error::Return(
+            body.as_ref()
+                .map(|body| body.interpret(env))
+                .unwrap_or(Ok(ConValue::Empty))?,
+        ))
+    }
+}
+impl Interpret for Break {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        let Self { body } = self;
+        Err(Error::Break(
+            body.as_ref()
+                .map(|body| body.interpret(env))
+                .unwrap_or(Ok(ConValue::Empty))?,
+        ))
+    }
+}

cl-interpret/src/lib.rs

@@ -0,0 +1,614 @@
+//! Walks a Conlang AST, interpreting it as a program.
+#![warn(clippy::all)]
+#![feature(decl_macro)]
+
+use env::Environment;
+use error::{Error, IResult};
+use interpret::Interpret;
+use temp_type_impl::ConValue;
+
+/// Callable types can be called from within a Conlang program
+pub trait Callable: std::fmt::Debug {
+    /// Calls this [Callable] in the provided [Environment], with [ConValue] args  \
+    /// The Callable is responsible for checking the argument count and validating types
+    fn call(&self, interpreter: &mut Environment, args: &[ConValue]) -> IResult<ConValue>;
+    /// Returns the common name of this identifier.
+    fn name(&self) -> &str;
+}
+
+/// [BuiltIn]s are [Callable]s with bespoke definitions
+pub trait BuiltIn: std::fmt::Debug + Callable {
+    fn description(&self) -> &str;
+}
+
+pub mod temp_type_impl {
+    //! Temporary implementations of Conlang values
+    //!
+    //! The most permanent fix is a temporary one.
+    use super::{
+        error::{Error, IResult},
+        function::Function,
+        BuiltIn, Callable, Environment,
+    };
+    use std::ops::*;
+
+    type Integer = isize;
+
+    /// A Conlang value
+    ///
+    /// This is a hack to work around the fact that Conlang doesn't
+    /// have a functioning type system yet :(
+    #[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(String),
+        /// An Array
+        Array(Vec<ConValue>),
+        /// A tuple
+        Tuple(Vec<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) -> &str {
+            match self {
+                ConValue::Function(func) => func.name(),
+                ConValue::BuiltIn(func) => func.name(),
+                _ => "",
+            }
+        }
+        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 { $v(value.into()) }
+        })*
+    }
+    from! {
+        Integer => ConValue::Int,
+        bool => ConValue::Bool,
+        char => ConValue::Char,
+        &str => ConValue::String,
+        String => ConValue::String,
+        Function => ConValue::Function,
+        Vec<ConValue> => ConValue::Tuple,
+        &'static dyn BuiltIn => ConValue::BuiltIn,
+    }
+    impl From<()> for ConValue {
+        fn from(_: ()) -> Self {
+            Self::Empty
+        }
+    }
+    impl From<&[ConValue]> for ConValue {
+        fn from(value: &[ConValue]) -> Self {
+            match value.len() {
+                0 => Self::Empty,
+                1 => value[0].clone(),
+                _ => Self::Tuple(value.into()),
+            }
+        }
+    }
+
+    /// Implements binary [std::ops] traits for [ConValue]
+    ///
+    /// TODO: Desugar operators into function calls
+    macro ops($($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 + b),
+            (ConValue::String(a), ConValue::String(b)) => ConValue::String(a + &b),
+            _ => 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 / b),
+            _ => Err(Error::TypeError)?
+        ]
+        Mul: mul = [
+            (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
+            (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a * b),
+            _ => Err(Error::TypeError)?
+        ]
+        Rem: rem = [
+            (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
+            (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a % b),
+            _ => Err(Error::TypeError)?
+        ]
+        Shl: shl = [
+            (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
+            (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a << b),
+            _ => Err(Error::TypeError)?
+        ]
+        Shr: shr = [
+            (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
+            (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a >> b),
+            _ => Err(Error::TypeError)?
+        ]
+        Sub: sub = [
+            (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
+            (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(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::Bool(v) => v.fmt(f),
+                ConValue::Char(v) => v.fmt(f),
+                ConValue::String(v) => v.fmt(f),
+                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) => {
+                    use cl_ast::format::*;
+                    use std::fmt::Write;
+                    write!(f.pretty(), "{}", func.decl())
+                }
+                ConValue::BuiltIn(func) => {
+                    write!(f, "{}", func.description())
+                }
+            }
+        }
+    }
+}
+
+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, Identifier, Param};
+    /// Represents a block of code which persists inside the Interpreter
+    #[derive(Clone, Debug)]
+    pub struct Function {
+        /// Stores the contents of the function declaration
+        decl: Box<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) -> &str {
+            let FnDecl { name: Identifier(ref name), .. } = *self.decl;
+            name
+        }
+        fn call(&self, env: &mut Environment, args: &[ConValue]) -> IResult<ConValue> {
+            let FnDecl { name: Identifier(name), args: declargs, body, rety: _ } = &*self.decl;
+            // Check arg mapping
+            if args.len() != declargs.len() {
+                return Err(Error::ArgNumber { want: declargs.len(), got: args.len() });
+            }
+            let Some(body) = body else {
+                return Err(Error::NotDefined(name.into()));
+            };
+            // TODO: completely refactor data storage
+            let mut frame = env.frame("fn args");
+            for (Param { mutability: _, name: Identifier(name), ty: _ }, value) in
+                declargs.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 builtin;
+
+pub mod env {
+    //! Lexical and non-lexical scoping for variables
+    use super::{
+        builtin::{BINARY, MISC, RANGE, UNARY},
+        error::{Error, IResult},
+        function::Function,
+        temp_type_impl::ConValue,
+        BuiltIn, Callable, Interpret,
+    };
+    use cl_ast::{Function as FnDecl, Identifier};
+    use std::{
+        collections::HashMap,
+        fmt::Display,
+        ops::{Deref, DerefMut},
+    };
+
+    /// Implements a nested lexical scope
+    #[derive(Clone, Debug)]
+    pub struct Environment {
+        frames: Vec<(HashMap<String, Option<ConValue>>, &'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<String, Option<ConValue>> {
+        from.iter()
+            .map(|&v| (v.name().into(), 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: &str, 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: &str) -> 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.into()))
+        }
+        /// Resolves a variable immutably.
+        ///
+        /// Returns a reference to the variable's contents, if it is defined and initialized.
+        pub fn get(&self, id: &str) -> IResult<&ConValue> {
+            for (frame, _) in self.frames.iter().rev() {
+                match frame.get(id) {
+                    Some(Some(var)) => return Ok(var),
+                    Some(None) => return Err(Error::NotInitialized(id.into())),
+                    _ => (),
+                }
+            }
+            Err(Error::NotDefined(id.into()))
+        }
+        /// Inserts a new [ConValue] into this [Environment]
+        pub fn insert(&mut self, id: &str, value: Option<ConValue>) {
+            if let Some((frame, _)) = self.frames.last_mut() {
+                frame.insert(id.into(), value);
+            }
+        }
+        /// A convenience function for registering a [FnDecl] as a [Function]
+        pub fn insert_fn(&mut self, decl: &FnDecl) {
+            let FnDecl { name: Identifier(name), .. } = decl;
+            let (name, function) = (name.clone(), 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 super::temp_type_impl::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(String),
+        /// A name was defined but not initialized
+        NotInitialized(String),
+        /// 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,
+        },
+        NullPointer,
+    }
+
+    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::NullPointer => {
+                    write!(f, "Attempted to dereference a null pointer?")
+                }
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests;

cl-interpret/src/tests.rs

@@ -1,10 +1,8 @@
 #![allow(unused_imports)]
-use crate::{
-    ast::*,
-    interpreter::{env::Environment, temp_type_impl::ConValue, Interpret},
-    lexer::Lexer,
-    parser::Parser,
-};
+use crate::{env::Environment, temp_type_impl::ConValue, Interpret};
+use cl_ast::*;
+use cl_lexer::Lexer;
+use cl_parser::Parser;
 pub use macros::*;
 
 mod macros {
@@ -49,7 +47,7 @@ mod macros {
     //! env_eq!(env.x, 10); // like assert_eq! for Environments
     //! ```
     #![allow(unused_macros)]
-    use crate::interpreter::IResult;
+    use crate::IResult;
 
     use super::*;
 
@@ -189,7 +187,7 @@ mod fn_declarations {
         assert_eval!(env, fn empty_fn() {});
         // TODO: true equality for functions
         assert_eq!(
-            "fn empty_fn",
+            "fn empty_fn () {\n    \n}",
             format!(
                 "{}",
                 env.get("empty_fn")
@@ -212,7 +210,7 @@ mod fn_declarations {
 }
 
 mod operators {
-    use crate::ast::Tuple;
+    use cl_ast::Tuple;
 
     use super::*;
     #[test]

cl-lexer/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "cl-lexer"
+repository.workspace = true
+version.workspace = true
+authors.workspace = true
+edition.workspace = true
+license.workspace = true
+publish.workspace = true
+
+[dependencies]
+cl-token = { path = "../cl-token" }
+cl-structures = { path = "../cl-structures" }
+unicode-ident = "1.0.12"

cl-lexer/src/lib.rs

@@ -1,10 +1,16 @@
 //! Converts a text file into tokens
-use crate::token::preamble::*;
+#![warn(clippy::all)]
+#![feature(decl_macro)]
+use cl_structures::span::Loc;
+use cl_token::{TokenKind as Kind, *};
 use std::{
     iter::Peekable,
     str::{Chars, FromStr},
 };
-use unicode_xid::UnicodeXID;
+use unicode_ident::*;
+
+#[cfg(test)]
+mod tests;
 
 pub mod lexer_iter {
     //! Iterator over a [`Lexer`], returning [`LResult<Token>`]s
@@ -45,7 +51,8 @@ pub mod lexer_iter {
 ///
 /// # Examples
 /// ```rust
-/// # use conlang::lexer::Lexer;
+/// # use cl_lexer::Lexer;
+/// # fn main() -> Result<(), Box<dyn std::error::Error>> {
 /// // Read in your code from somewhere
 /// let some_code = "
 /// fn main () {
@@ -55,16 +62,17 @@ pub mod lexer_iter {
 /// // Create a lexer over your code
 /// let mut lexer = Lexer::new(some_code);
 /// // Scan for a single token
-/// let first_token = lexer.scan().unwrap();
+/// let first_token = lexer.scan()?;
 /// println!("{first_token:?}");
 /// // Loop over all the rest of the tokens
 /// for token in lexer {
-/// #   let token: Result<_,()> = Ok(token.unwrap());
+/// #   let token: Result<_,()> = Ok(token?);
 ///     match token {
 ///         Ok(token) => println!("{token:?}"),
 ///         Err(e) => eprintln!("{e:?}"),
 ///     }
 /// }
+/// # Ok(()) }
 /// ```
 #[derive(Clone, Debug)]
 pub struct Lexer<'t> {
@@ -89,40 +97,40 @@ 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(Type::LCurly, ()),
-            '}' => self.consume()?.produce(Type::RCurly, ()),
-            '[' => self.consume()?.produce(Type::LBrack, ()),
-            ']' => self.consume()?.produce(Type::RBrack, ()),
-            '(' => self.consume()?.produce(Type::LParen, ()),
-            ')' => self.consume()?.produce(Type::RParen, ()),
+            '{' => 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()?.amp(),
-            '@' => self.consume()?.produce(Type::At, ()),
-            '\\' => self.consume()?.produce(Type::Backslash, ()),
+            '@' => self.consume()?.produce_op(Punct::At),
+            '\\' => self.consume()?.produce_op(Punct::Backslash),
             '!' => self.consume()?.bang(),
             '|' => self.consume()?.bar(),
             ':' => self.consume()?.colon(),
-            ',' => self.consume()?.produce(Type::Comma, ()),
+            ',' => self.consume()?.produce_op(Punct::Comma),
             '.' => self.consume()?.dot(),
             '=' => self.consume()?.equal(),
-            '`' => self.consume()?.produce(Type::Grave, ()),
+            '`' => self.consume()?.produce_op(Punct::Grave),
             '>' => self.consume()?.greater(),
             '#' => self.consume()?.hash(),
             '<' => self.consume()?.less(),
             '-' => self.consume()?.minus(),
             '+' => self.consume()?.plus(),
-            '?' => self.consume()?.produce(Type::Question, ()),
+            '?' => self.consume()?.produce_op(Punct::Question),
             '%' => self.consume()?.rem(),
-            ';' => self.consume()?.produce(Type::Semi, ()),
+            ';' => self.consume()?.produce_op(Punct::Semi),
             '/' => self.consume()?.slash(),
             '*' => self.consume()?.star(),
-            '~' => self.consume()?.produce(Type::Tilde, ()),
+            '~' => self.consume()?.produce_op(Punct::Tilde),
             '^' => self.consume()?.xor(),
             '0' => self.consume()?.int_with_base(),
             '1'..='9' => self.digits::<10>(),
             '"' => self.consume()?.string(),
             '\'' => self.consume()?.character(),
             '_' => self.identifier(),
-            i if i.is_xid_start() => self.identifier(),
+            i if is_xid_start(i) => self.identifier(),
             e => {
                 let err = Err(Error::unexpected_char(e, self.line(), self.col()));
                 let _ = self.consume();
@@ -149,11 +157,14 @@ impl<'t> Lexer<'t> {
             .copied()
             .ok_or(Error::end_of_file(self.line(), self.col()))
     }
-    fn produce(&mut self, ty: Type, data: impl Into<Data>) -> LResult<Token> {
+    fn produce(&mut self, kind: TokenKind, data: impl Into<TokenData>) -> LResult<Token> {
         let loc = self.start_loc;
         self.start_loc = self.current_loc;
         self.start = self.current;
-        Ok(Token::new(ty, data, loc.0, loc.1))
+        Ok(Token::new(kind, data, loc.0, loc.1))
+    }
+    fn produce_op(&mut self, kind: Punct) -> LResult<Token> {
+        self.produce(TokenKind::Punct(kind), ())
     }
     fn skip_whitespace(&mut self) -> &mut Self {
         while let Ok(c) = self.peek() {
@@ -184,120 +195,120 @@ impl<'t> Lexer<'t> {
 impl<'t> Lexer<'t> {
     fn amp(&mut self) -> LResult<Token> {
         match self.peek() {
-            Ok('&') => self.consume()?.produce(Type::AmpAmp, ()),
-            Ok('=') => self.consume()?.produce(Type::AmpEq, ()),
-            _ => self.produce(Type::Amp, ()),
+            Ok('&') => self.consume()?.produce_op(Punct::AmpAmp),
+            Ok('=') => self.consume()?.produce_op(Punct::AmpEq),
+            _ => self.produce_op(Punct::Amp),
         }
     }
     fn bang(&mut self) -> LResult<Token> {
         match self.peek() {
-            Ok('!') => self.consume()?.produce(Type::BangBang, ()),
-            Ok('=') => self.consume()?.produce(Type::BangEq, ()),
-            _ => self.produce(Type::Bang, ()),
+            Ok('!') => self.consume()?.produce_op(Punct::BangBang),
+            Ok('=') => self.consume()?.produce_op(Punct::BangEq),
+            _ => self.produce_op(Punct::Bang),
         }
     }
     fn bar(&mut self) -> LResult<Token> {
         match self.peek() {
-            Ok('|') => self.consume()?.produce(Type::BarBar, ()),
-            Ok('=') => self.consume()?.produce(Type::BarEq, ()),
-            _ => self.produce(Type::Bar, ()),
+            Ok('|') => self.consume()?.produce_op(Punct::BarBar),
+            Ok('=') => self.consume()?.produce_op(Punct::BarEq),
+            _ => self.produce_op(Punct::Bar),
         }
     }
     fn colon(&mut self) -> LResult<Token> {
         match self.peek() {
-            Ok(':') => self.consume()?.produce(Type::ColonColon, ()),
-            _ => self.produce(Type::Colon, ()),
+            Ok(':') => self.consume()?.produce_op(Punct::ColonColon),
+            _ => self.produce_op(Punct::Colon),
         }
     }
     fn dot(&mut self) -> LResult<Token> {
         match self.peek() {
             Ok('.') => {
                 if let Ok('=') = self.consume()?.peek() {
-                    self.consume()?.produce(Type::DotDotEq, ())
+                    self.consume()?.produce_op(Punct::DotDotEq)
                 } else {
-                    self.produce(Type::DotDot, ())
+                    self.produce_op(Punct::DotDot)
                 }
             }
-            _ => self.produce(Type::Dot, ()),
+            _ => self.produce_op(Punct::Dot),
         }
     }
     fn equal(&mut self) -> LResult<Token> {
         match self.peek() {
-            Ok('=') => self.consume()?.produce(Type::EqEq, ()),
-            Ok('>') => self.consume()?.produce(Type::FatArrow, ()),
-            _ => self.produce(Type::Eq, ()),
+            Ok('=') => self.consume()?.produce_op(Punct::EqEq),
+            Ok('>') => self.consume()?.produce_op(Punct::FatArrow),
+            _ => self.produce_op(Punct::Eq),
         }
     }
     fn greater(&mut self) -> LResult<Token> {
         match self.peek() {
-            Ok('=') => self.consume()?.produce(Type::GtEq, ()),
+            Ok('=') => self.consume()?.produce_op(Punct::GtEq),
             Ok('>') => {
                 if let Ok('=') = self.consume()?.peek() {
-                    self.consume()?.produce(Type::GtGtEq, ())
+                    self.consume()?.produce_op(Punct::GtGtEq)
                 } else {
-                    self.produce(Type::GtGt, ())
+                    self.produce_op(Punct::GtGt)
                 }
             }
-            _ => self.produce(Type::Gt, ()),
+            _ => self.produce_op(Punct::Gt),
         }
     }
     fn hash(&mut self) -> LResult<Token> {
         match self.peek() {
-            Ok('!') => self.consume()?.produce(Type::HashBang, ()),
-            _ => self.produce(Type::Hash, ()),
+            Ok('!') => self.consume()?.produce_op(Punct::HashBang),
+            _ => self.produce_op(Punct::Hash),
         }
     }
     fn less(&mut self) -> LResult<Token> {
         match self.peek() {
-            Ok('=') => self.consume()?.produce(Type::LtEq, ()),
+            Ok('=') => self.consume()?.produce_op(Punct::LtEq),
             Ok('<') => {
                 if let Ok('=') = self.consume()?.peek() {
-                    self.consume()?.produce(Type::LtLtEq, ())
+                    self.consume()?.produce_op(Punct::LtLtEq)
                 } else {
-                    self.produce(Type::LtLt, ())
+                    self.produce_op(Punct::LtLt)
                 }
             }
-            _ => self.produce(Type::Lt, ()),
+            _ => self.produce_op(Punct::Lt),
         }
     }
     fn minus(&mut self) -> LResult<Token> {
         match self.peek() {
-            Ok('=') => self.consume()?.produce(Type::MinusEq, ()),
-            Ok('>') => self.consume()?.produce(Type::Arrow, ()),
-            _ => self.produce(Type::Minus, ()),
+            Ok('=') => self.consume()?.produce_op(Punct::MinusEq),
+            Ok('>') => self.consume()?.produce_op(Punct::Arrow),
+            _ => self.produce_op(Punct::Minus),
         }
     }
     fn plus(&mut self) -> LResult<Token> {
         match self.peek() {
-            Ok('=') => self.consume()?.produce(Type::PlusEq, ()),
-            _ => self.produce(Type::Plus, ()),
+            Ok('=') => self.consume()?.produce_op(Punct::PlusEq),
+            _ => self.produce_op(Punct::Plus),
         }
     }
     fn rem(&mut self) -> LResult<Token> {
         match self.peek() {
-            Ok('=') => self.consume()?.produce(Type::RemEq, ()),
-            _ => self.produce(Type::Rem, ()),
+            Ok('=') => self.consume()?.produce_op(Punct::RemEq),
+            _ => self.produce_op(Punct::Rem),
         }
     }
     fn slash(&mut self) -> LResult<Token> {
         match self.peek() {
-            Ok('=') => self.consume()?.produce(Type::SlashEq, ()),
+            Ok('=') => self.consume()?.produce_op(Punct::SlashEq),
             Ok('/') => self.consume()?.line_comment(),
             Ok('*') => self.consume()?.block_comment(),
-            _ => self.produce(Type::Slash, ()),
+            _ => self.produce_op(Punct::Slash),
         }
     }
     fn star(&mut self) -> LResult<Token> {
         match self.peek() {
-            Ok('=') => self.consume()?.produce(Type::StarEq, ()),
-            _ => self.produce(Type::Star, ()),
+            Ok('=') => self.consume()?.produce_op(Punct::StarEq),
+            _ => self.produce_op(Punct::Star),
         }
     }
     fn xor(&mut self) -> LResult<Token> {
         match self.peek() {
-            Ok('=') => self.consume()?.produce(Type::XorEq, ()),
-            Ok('^') => self.consume()?.produce(Type::XorXor, ()),
-            _ => self.produce(Type::Xor, ()),
+            Ok('=') => self.consume()?.produce_op(Punct::XorEq),
+            Ok('^') => self.consume()?.produce_op(Punct::XorXor),
+            _ => self.produce_op(Punct::Xor),
         }
     }
 }
@@ -307,7 +318,7 @@ impl<'t> Lexer<'t> {
         while Ok('\n') != self.peek() {
             self.consume()?;
         }
-        self.produce(Type::Comment, ())
+        self.produce(Kind::Comment, ())
     }
     fn block_comment(&mut self) -> LResult<Token> {
         while let Ok(c) = self.next() {
@@ -315,7 +326,7 @@ impl<'t> Lexer<'t> {
                 break;
             }
         }
-        self.produce(Type::Comment, ())
+        self.produce(Kind::Comment, ())
     }
 }
 /// Identifiers
@@ -325,15 +336,15 @@ impl<'t> Lexer<'t> {
         while let Ok(c) = self.xid_continue() {
             out.push(c)
         }
-        if let Ok(keyword) = Keyword::from_str(&out) {
-            self.produce(Type::Keyword(keyword), ())
+        if let Ok(keyword) = Kind::from_str(&out) {
+            self.produce(keyword, ())
         } else {
-            self.produce(Type::Identifier, Data::Identifier(out.into()))
+            self.produce(Kind::Identifier, TokenData::String(out))
         }
     }
     fn xid_start(&mut self) -> LResult<char> {
         match self.peek()? {
-            xid if xid == '_' || xid.is_xid_start() => {
+            xid if xid == '_' || is_xid_start(xid) => {
                 self.consume()?;
                 Ok(xid)
             }
@@ -342,7 +353,7 @@ impl<'t> Lexer<'t> {
     }
     fn xid_continue(&mut self) -> LResult<char> {
         match self.peek()? {
-            xid if xid.is_xid_continue() => {
+            xid if is_xid_continue(xid) => {
                 self.consume()?;
                 Ok(xid)
             }
@@ -359,7 +370,7 @@ impl<'t> Lexer<'t> {
             Ok('o') => self.consume()?.digits::<8>(),
             Ok('b') => self.consume()?.digits::<2>(),
             Ok('0'..='9') => self.digits::<10>(),
-            _ => self.produce(Type::Integer, 0),
+            _ => self.produce(Kind::Literal, 0),
         }
     }
     fn digits<const B: u32>(&mut self) -> LResult<Token> {
@@ -367,7 +378,7 @@ impl<'t> Lexer<'t> {
         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(Type::Integer, value)
+        self.produce(Kind::Literal, value)
     }
     fn digit<const B: u32>(&mut self) -> LResult<u32> {
         let digit = self.peek()?;
@@ -388,12 +399,12 @@ impl<'t> Lexer<'t> {
         {
             value.push(self.unescape()?)
         }
-        self.consume()?.produce(Type::String, value)
+        self.consume()?.produce(Kind::Literal, value)
     }
     fn character(&mut self) -> LResult<Token> {
         let out = self.unescape()?;
         match self.peek()? {
-            '\'' => self.consume()?.produce(Type::Character, out),
+            '\'' => self.consume()?.produce(Kind::Literal, out),
             _ => Err(Error::unmatched_delimiters('\'', self.line(), self.col())),
         }
     }
@@ -445,6 +456,12 @@ impl<'t> Lexer<'t> {
     }
 }
 
+impl<'t> From<&Lexer<'t>> for Loc {
+    fn from(value: &Lexer<'t>) -> Self {
+        Loc(value.line(), value.col())
+    }
+}
+
 use error::{Error, LResult, Reason};
 pub mod error {
     //! [Error] type for the [Lexer](super::Lexer)
@@ -463,7 +480,7 @@ pub mod error {
     pub enum Reason {
         /// Found an opening delimiter of type [char], but not the expected closing delimiter
         UnmatchedDelimiters(char),
-        /// Found a character that doesn't belong to any [Type](crate::token::token_type::Type)
+        /// Found a character that doesn't belong to any [TokenKind](cl_token::TokenKind)
         UnexpectedChar(char),
         /// Found a character that's not valid in identifiers while looking for an identifier
         NotIdentifier(char),

cl-lexer/src/tests.rs

@@ -0,0 +1,171 @@
+use crate::Lexer;
+use cl_token::*;
+
+macro test_lexer_output_type  ($($f:ident {$($test:expr => $expect:expr),*$(,)?})*) {$(
+    #[test]
+    fn $f() {$(
+        assert_eq!(
+            Lexer::new($test)
+                .into_iter()
+                .map(|t| t.unwrap().ty())
+                .collect::<Vec<_>>(),
+            dbg!($expect)
+        );
+    )*}
+)*}
+
+macro test_lexer_data_type  ($($f:ident {$($test:expr => $expect:expr),*$(,)?})*) {$(
+    #[test]
+    fn $f() {$(
+        assert_eq!(
+            Lexer::new($test)
+                .into_iter()
+                .map(|t| t.unwrap().into_data())
+                .collect::<Vec<_>>(),
+            dbg!($expect)
+        );
+    )*}
+)*}
+
+/// Convert an `[ expr, ... ]` into a `[ *, ... ]`
+macro td ($($id:expr),*) {
+    [$($id.into()),*]
+}
+
+mod ident {
+    use super::*;
+    macro ident ($($id:literal),*) {
+        [$(TokenData::String($id.into())),*]
+    }
+    test_lexer_data_type! {
+        underscore { "_ _" => ident!["_", "_"] }
+        unicode { "_ε ε_" => ident!["_ε", "ε_"] }
+        many_underscore { "____________________________________" =>
+        ident!["____________________________________"] }
+    }
+}
+mod keyword {
+    use super::*;
+    macro kw($($k:ident),*) {
+        [ $(TokenKind::$k,)* ]
+    }
+    test_lexer_output_type! {
+        kw_break { "break break" => kw![Break, Break] }
+        kw_continue { "continue continue" => kw![Continue, Continue] }
+        kw_else { "else else" => kw![Else, Else] }
+        kw_false { "false false" => kw![False, False] }
+        kw_for { "for for" => kw![For, For] }
+        kw_fn { "fn fn" => kw![Fn, Fn] }
+        kw_if { "if if" => kw![If, If] }
+        kw_in { "in in" => kw![In, In] }
+        kw_let { "let let" => kw![Let, Let] }
+        kw_return { "return return" => kw![Return, Return] }
+        kw_true { "true true" => kw![True, True] }
+        kw_while { "while while" => kw![While, While] }
+        keywords { "break continue else false for fn if in let return true while" =>
+            kw![Break, Continue, Else, False, For, Fn, If, In, Let, Return, True, While] }
+    }
+}
+mod integer {
+    use super::*;
+    test_lexer_data_type! {
+        hex {
+            "0x0 0x1 0x15 0x2100 0x8000" =>
+            td![0x0, 0x1, 0x15, 0x2100, 0x8000]
+        }
+        dec {
+            "0d0 0d1 0d21 0d8448 0d32768" =>
+            td![0, 0x1, 0x15, 0x2100, 0x8000]
+        }
+        oct {
+            "0o0 0o1 0o25 0o20400 0o100000" =>
+            td![0x0, 0x1, 0x15, 0x2100, 0x8000]
+        }
+        bin {
+            "0b0 0b1 0b10101 0b10000100000000 0b1000000000000000" =>
+            td![0x0, 0x1, 0x15, 0x2100, 0x8000]
+        }
+        baseless {
+            "0 1 21 8448 32768" =>
+            td![0x0, 0x1, 0x15, 0x2100, 0x8000]
+        }
+    }
+}
+mod string {
+    use super::*;
+    test_lexer_data_type! {
+        empty_string {
+            "\"\"" =>
+            td![String::from("")]
+        }
+        unicode_string {
+            "\"I 💙 🦈!\"" =>
+            td![String::from("I 💙 🦈!")]
+        }
+        escape_string {
+            " \"This is a shark: \\u{1f988}\" " =>
+            td![String::from("This is a shark: 🦈")]
+        }
+    }
+}
+mod punct {
+    macro op($op:ident) {
+        TokenKind::Punct(Punct::$op)
+    }
+
+    use super::*;
+    test_lexer_output_type! {
+        l_curly   { "{ {"   => [ op!(LCurly), op!(LCurly) ] }
+        r_curly   { "} }"   => [ op!(RCurly), op!(RCurly) ] }
+        l_brack   { "[ ["   => [ op!(LBrack), op!(LBrack) ] }
+        r_brack   { "] ]"   => [ op!(RBrack), op!(RBrack) ] }
+        l_paren   { "( ("   => [ op!(LParen), op!(LParen) ] }
+        r_paren   { ") )"   => [ op!(RParen), op!(RParen) ] }
+        amp       { "& &"   => [ op!(Amp), op!(Amp) ] }
+        amp_amp   { "&& &&" => [ op!(AmpAmp), op!(AmpAmp) ] }
+        amp_eq    { "&= &=" => [ op!(AmpEq), op!(AmpEq) ] }
+        arrow     { "-> ->" => [ op!(Arrow), op!(Arrow)] }
+        at        { "@ @"   => [ op!(At), op!(At)] }
+        backslash { "\\ \\" => [ op!(Backslash), op!(Backslash)] }
+        bang      { "! !"   => [ op!(Bang), op!(Bang)] }
+        bangbang  { "!! !!" => [ op!(BangBang), op!(BangBang)] }
+        bangeq    { "!= !=" => [ op!(BangEq), op!(BangEq)] }
+        bar       { "| |"   => [ op!(Bar), op!(Bar)] }
+        barbar    { "|| ||" => [ op!(BarBar), op!(BarBar)] }
+        bareq     { "|= |=" => [ op!(BarEq), op!(BarEq)] }
+        colon     { ": :"   => [ op!(Colon), op!(Colon)] }
+        comma     { ", ,"   => [ op!(Comma), op!(Comma)] }
+        dot       { ". ."   => [ op!(Dot), op!(Dot)] }
+        dotdot    { ".. .." => [ op!(DotDot), op!(DotDot)] }
+        dotdoteq  { "..= ..=" => [ op!(DotDotEq), op!(DotDotEq)] }
+        eq        { "= ="   => [ op!(Eq), op!(Eq)] }
+        eqeq      { "== ==" => [ op!(EqEq), op!(EqEq)] }
+        fatarrow  { "=> =>" => [ op!(FatArrow), op!(FatArrow)] }
+        grave     { "` `"   => [ op!(Grave), op!(Grave)] }
+        gt        { "> >"   => [ op!(Gt), op!(Gt)] }
+        gteq      { ">= >=" => [ op!(GtEq), op!(GtEq)] }
+        gtgt      { ">> >>" => [ op!(GtGt), op!(GtGt)] }
+        gtgteq    { ">>= >>=" => [ op!(GtGtEq), op!(GtGtEq)] }
+        hash      { "# #"   => [ op!(Hash), op!(Hash)] }
+        lt        { "< <"   => [ op!(Lt), op!(Lt)] }
+        lteq      { "<= <=" => [ op!(LtEq), op!(LtEq)] }
+        ltlt      { "<< <<" => [ op!(LtLt), op!(LtLt)] }
+        ltlteq    { "<<= <<=" => [ op!(LtLtEq), op!(LtLtEq)] }
+        minus     { "- -"   => [ op!(Minus), op!(Minus)] }
+        minuseq   { "-= -=" => [ op!(MinusEq), op!(MinusEq)] }
+        plus      { "+ +"   => [ op!(Plus), op!(Plus)] }
+        pluseq    { "+= +=" => [ op!(PlusEq), op!(PlusEq)] }
+        question  { "? ?"   => [ op!(Question), op!(Question)] }
+        rem       { "% %"   => [ op!(Rem), op!(Rem)] }
+        remeq     { "%= %=" => [ op!(RemEq), op!(RemEq)] }
+        semi      { "; ;"   => [ op!(Semi), op!(Semi)] }
+        slash     { "/ /"   => [ op!(Slash), op!(Slash)] }
+        slasheq   { "/= /=" => [ op!(SlashEq), op!(SlashEq)] }
+        star      { "* *"   => [ op!(Star), op!(Star)] }
+        stareq    { "*= *=" => [ op!(StarEq), op!(StarEq)] }
+        tilde     { "~ ~"   => [ op!(Tilde), op!(Tilde)] }
+        xor       { "^ ^"   => [ op!(Xor), op!(Xor)] }
+        xoreq     { "^= ^=" => [ op!(XorEq), op!(XorEq)] }
+        xorxor    { "^^ ^^" => [ op!(XorXor), op!(XorXor)] }
+    }
+}

cl-parser/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "cl-parser"
+repository.workspace = true
+version.workspace = true
+authors.workspace = true
+edition.workspace = true
+license.workspace = true
+publish.workspace = true
+
+[dependencies]
+cl-ast = { path = "../cl-ast" }
+cl-lexer = { path = "../cl-lexer" }
+cl-token = { path = "../cl-token" }
+cl-structures = { path = "../cl-structures" }

cl-parser/src/error.rs

@@ -0,0 +1,209 @@
+use super::*;
+
+use cl_lexer::error::{Error as LexError, Reason};
+use std::fmt::Display;
+pub type PResult<T> = Result<T, Error>;
+
+/// Contains information about [Parser] errors
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct Error {
+    pub reason: ErrorKind,
+    pub while_parsing: Parsing,
+    pub loc: Loc,
+}
+impl std::error::Error for Error {}
+
+/// Represents the reason for parse failure
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum ErrorKind {
+    Lexical(LexError),
+    EndOfInput,
+    UnmatchedParentheses,
+    UnmatchedCurlyBraces,
+    UnmatchedSquareBrackets,
+    Unexpected(TokenKind),
+    Expected {
+        want: TokenKind,
+        got: TokenKind,
+    },
+    /// No rules matched
+    Nothing,
+    /// Indicates unfinished code
+    Todo,
+}
+impl From<LexError> for ErrorKind {
+    fn from(value: LexError) -> Self {
+        match value.reason() {
+            Reason::EndOfFile => Self::EndOfInput,
+            _ => Self::Lexical(value),
+        }
+    }
+}
+
+/// Compactly represents the stage of parsing an [Error] originated in
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum Parsing {
+    File,
+
+    Attrs,
+    Meta,
+
+    Item,
+    Visibility,
+    Mutability,
+    ItemKind,
+    Alias,
+    Const,
+    Static,
+    Module,
+    ModuleKind,
+    Function,
+    Param,
+    Struct,
+    StructKind,
+    StructMember,
+    Enum,
+    EnumKind,
+    Variant,
+    VariantKind,
+    Impl,
+
+    Ty,
+    TyKind,
+    TyTuple,
+    TyRef,
+    TyFn,
+
+    Stmt,
+    StmtKind,
+    Let,
+
+    Expr,
+    ExprKind,
+    Assign,
+    AssignKind,
+    Binary,
+    BinaryKind,
+    Unary,
+    UnaryKind,
+    Index,
+    Call,
+    Member,
+    PathExpr,
+    PathPart,
+    Identifier,
+    Literal,
+    Array,
+    ArrayRep,
+    AddrOf,
+    Block,
+    Group,
+    Tuple,
+    While,
+    If,
+    For,
+    Else,
+    Break,
+    Return,
+    Continue,
+}
+
+impl Display for Error {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let Self { reason, while_parsing, loc } = self;
+        match reason {
+            // TODO entries are debug-printed
+            ErrorKind::Todo => write!(f, "{loc} {reason} {while_parsing:?}"),
+            // lexical errors print their own higher-resolution loc info
+            ErrorKind::Lexical(e) => write!(f, "{e} (while parsing {while_parsing})"),
+            _ => write!(f, "{loc} {reason} while parsing {while_parsing}"),
+        }
+    }
+}
+impl Display for ErrorKind {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            ErrorKind::Lexical(e) => e.fmt(f),
+            ErrorKind::EndOfInput => write!(f, "End of input"),
+            ErrorKind::UnmatchedParentheses => write!(f, "Unmatched parentheses"),
+            ErrorKind::UnmatchedCurlyBraces => write!(f, "Unmatched curly braces"),
+            ErrorKind::UnmatchedSquareBrackets => write!(f, "Unmatched square brackets"),
+            ErrorKind::Unexpected(t) => write!(f, "Encountered unexpected token `{t}`"),
+            ErrorKind::Expected { want: e, got: g } => {
+                write!(f, "Expected `{e}`, got `{g}`")
+            }
+            ErrorKind::Nothing => write!(f, "Nothing found"),
+            ErrorKind::Todo => write!(f, "TODO:"),
+        }
+    }
+}
+impl Display for Parsing {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Parsing::File => "a file",
+
+            Parsing::Attrs => "an attribute-set",
+            Parsing::Meta => "an attribute",
+
+            Parsing::Item => "an item",
+            Parsing::Visibility => "a visibility qualifier",
+            Parsing::Mutability => "a mutability qualifier",
+            Parsing::ItemKind => "an item",
+            Parsing::Alias => "a type alias",
+            Parsing::Const => "a const item",
+            Parsing::Static => "a static variable",
+            Parsing::Module => "a module",
+            Parsing::ModuleKind => "a module",
+            Parsing::Function => "a function",
+            Parsing::Param => "a function parameter",
+            Parsing::Struct => "a struct",
+            Parsing::StructKind => "a struct",
+            Parsing::StructMember => "a struct member",
+            Parsing::Enum => "an enum",
+            Parsing::EnumKind => "an enum",
+            Parsing::Variant => "an enum variant",
+            Parsing::VariantKind => "an enum variant",
+            Parsing::Impl => "an impl block",
+
+            Parsing::Ty => "a type",
+            Parsing::TyKind => "a type",
+            Parsing::TyTuple => "a tuple of types",
+            Parsing::TyRef => "a reference type",
+            Parsing::TyFn => "a function pointer type",
+
+            Parsing::Stmt => "a statement",
+            Parsing::StmtKind => "a statement",
+            Parsing::Let => "a local variable declaration",
+
+            Parsing::Expr => "an expression",
+            Parsing::ExprKind => "an expression",
+            Parsing::Assign => "an assignment",
+            Parsing::AssignKind => "an assignment operator",
+            Parsing::Binary => "a binary expression",
+            Parsing::BinaryKind => "a binary operator",
+            Parsing::Unary => "a unary expression",
+            Parsing::UnaryKind => "a unary operator",
+            Parsing::Index => "an indexing expression",
+            Parsing::Call => "a call expression",
+            Parsing::Member => "a member access expression",
+            Parsing::PathExpr => "a path",
+            Parsing::PathPart => "a path component",
+            Parsing::Identifier => "an identifier",
+            Parsing::Literal => "a literal",
+            Parsing::Array => "an array",
+            Parsing::ArrayRep => "an array of form [k;N]",
+            Parsing::AddrOf => "a borrow op",
+            Parsing::Block => "a block",
+            Parsing::Group => "a grouped expression",
+            Parsing::Tuple => "a tuple",
+            Parsing::While => "a while expression",
+            Parsing::If => "an if expression",
+            Parsing::For => "a for expression",
+            Parsing::Else => "an else block",
+            Parsing::Break => "a break expression",
+            Parsing::Return => "a return expression",
+            Parsing::Continue => "a continue expression",
+        }
+        .fmt(f)
+    }
+}

cl-parser/src/lib.rs

@@ -0,0 +1,16 @@
+//! Parses [tokens](cl_token::token) into an [AST](cl_ast)
+//!
+//! For the full grammar, see [grammar.ebnf][1]
+//!
+//! [1]: https://git.soft.fish/j/Conlang/src/branch/main/grammar.ebnf
+#![warn(clippy::all)]
+#![feature(decl_macro)]
+
+pub use parser::Parser;
+
+use cl_structures::span::*;
+use cl_token::*;
+
+pub mod error;
+
+pub mod parser;

cl-repl/Cargo.toml

@@ -10,5 +10,14 @@ publish.workspace = true
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-conlang = { path = "../libconlang" }
+cl-ast = { path = "../cl-ast" }
+cl-lexer = { path = "../cl-lexer" }
+cl-token = { path = "../cl-token" }
+cl-parser = { path = "../cl-parser" }
+cl-interpret = { path = "../cl-interpret" }
 crossterm = "0.27.0"
+argh = "0.1.12"
+
+[dev-dependencies]
+cl-structures = { path = "../cl-structures" }
+cl-typeck = { path = "../cl-typeck" }

cl-repl/examples/collect-identifiers.rs

@@ -1,523 +0,0 @@
-//! Collects identifiers into a list
-
-use cl_repl::repline::Repline;
-use conlang::{common::Loc, lexer::Lexer, parser::Parser};
-use std::{
-    collections::HashMap,
-    error::Error,
-    fmt::Display,
-    ops::{Deref, DerefMut},
-};
-
-fn main() -> Result<(), Box<dyn Error>> {
-    let mut rl = Repline::new("\x1b[33m", "cl>", "? >");
-    while let Ok(line) = rl.read() {
-        let mut parser = Parser::new(Lexer::new(&line));
-        let code = match parser.stmt() {
-            Ok(code) => {
-                rl.accept();
-                code
-            }
-            Err(_) => {
-                continue;
-            }
-        };
-        let c = Collector::from(&code);
-        print!("\x1b[G\x1b[J{c}");
-    }
-    Ok(())
-}
-
-/// Ties the [Collector] location stack to the program stack
-pub struct CollectorLoc<'loc, 'code> {
-    inner: &'loc mut Collector<'code>,
-}
-impl<'l, 'c> CollectorLoc<'l, 'c> {
-    pub fn new(c: &'l mut Collector<'c>, loc: Loc) -> Self {
-        c.location.push(loc);
-        Self { inner: c }
-    }
-}
-impl<'l, 'c> Deref for CollectorLoc<'l, 'c> {
-    type Target = Collector<'c>;
-    fn deref(&self) -> &Self::Target {
-        self.inner
-    }
-}
-impl<'l, 'c> DerefMut for CollectorLoc<'l, 'c> {
-    fn deref_mut(&mut self) -> &mut Self::Target {
-        self.inner
-    }
-}
-impl<'l, 'c> Drop for CollectorLoc<'l, 'c> {
-    fn drop(&mut self) {
-        let Self { inner: c } = self;
-        c.location.pop();
-    }
-}
-
-#[derive(Clone, Debug, Default)]
-pub struct Collector<'code> {
-    location: Vec<Loc>,
-    defs: HashMap<&'code str, Vec<Loc>>,
-    refs: HashMap<&'code str, Vec<Loc>>,
-}
-
-impl<'c> Collector<'c> {
-    pub fn new() -> Self {
-        Self::default()
-    }
-    pub fn location<'loc>(&'loc mut self, loc: Loc) -> CollectorLoc<'loc, 'c> {
-        CollectorLoc::new(self, loc)
-    }
-    pub fn collect(&mut self, collectible: &'c impl Collectible<'c>) -> &mut Self {
-        collectible.collect(self);
-        self
-    }
-    pub fn define(&mut self, name: &'c str) -> &mut Self {
-        // println!("Inserted definition of {name}");
-        let loc = self.location.last().copied().unwrap_or(Loc(0, 0));
-        self.defs
-            .entry(name)
-            .and_modify(|c| c.push(loc))
-            .or_insert_with(|| vec![loc]);
-        self
-    }
-    pub fn reference(&mut self, name: &'c str) -> &mut Self {
-        // println!("Inserted usage of {name}");
-        let loc = self.location.last().copied().unwrap_or(Loc(0, 0));
-        self.refs
-            .entry(name)
-            .and_modify(|c| c.push(loc))
-            .or_insert_with(|| vec![loc]);
-        self
-    }
-}
-impl<'c> Display for Collector<'c> {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        let Self { location: _, defs, refs } = self;
-        writeln!(f, "Definitions:")?;
-        for (name, locs) in defs {
-            for loc in locs {
-                writeln!(f, "{loc} {name}")?;
-            }
-        }
-        writeln!(f, "Usages:")?;
-        for (name, locs) in refs {
-            for loc in locs {
-                writeln!(f, "{loc} {name}")?;
-            }
-        }
-        Ok(())
-    }
-}
-
-impl<'c, C: Collectible<'c>> From<&'c C> for Collector<'c> {
-    fn from(value: &'c C) -> Self {
-        let mut c = Self::new();
-        c.collect(value);
-        c
-    }
-}
-
-use collectible::Collectible;
-pub mod collectible {
-
-    use super::Collector;
-    use conlang::ast::*;
-    pub trait Collectible<'code> {
-        fn collect(&'code self, c: &mut Collector<'code>);
-    }
-
-    impl<'c> Collectible<'c> for File {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let File { items } = self;
-            for item in items {
-                item.collect(c)
-            }
-        }
-    }
-    impl<'c> Collectible<'c> for Item {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { extents, attrs: _, vis: _, kind } = self;
-            kind.collect(&mut c.location(extents.head));
-        }
-    }
-    impl<'c> Collectible<'c> for ItemKind {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            match self {
-                ItemKind::Alias(f) => f.collect(c),
-                ItemKind::Const(f) => f.collect(c),
-                ItemKind::Static(f) => f.collect(c),
-                ItemKind::Module(f) => f.collect(c),
-                ItemKind::Function(f) => f.collect(c),
-                ItemKind::Struct(f) => f.collect(c),
-                ItemKind::Enum(f) => f.collect(c),
-                ItemKind::Impl(f) => f.collect(c),
-            }
-        }
-    }
-    impl<'c> Collectible<'c> for Alias {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { to, from } = self;
-            c.collect(to).collect(from);
-        }
-    }
-    impl<'c> Collectible<'c> for Const {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { name: Identifier(name), ty, init } = self;
-            c.define(name).collect(init).collect(ty);
-        }
-    }
-    impl<'c> Collectible<'c> for Static {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { mutable: _, name: Identifier(name), ty, init } = self;
-            c.define(name).collect(init).collect(ty);
-        }
-    }
-    impl<'c> Collectible<'c> for Module {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { name: Identifier(name), kind } = self;
-            c.define(name).collect(kind);
-        }
-    }
-    impl<'c> Collectible<'c> for ModuleKind {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            match self {
-                ModuleKind::Inline(f) => f.collect(c),
-                ModuleKind::Outline => {}
-            }
-        }
-    }
-    impl<'c> Collectible<'c> for Function {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { name: Identifier(name), args, body, rety } = self;
-            c.define(name).collect(args).collect(body).collect(rety);
-        }
-    }
-    impl<'c> Collectible<'c> for Struct {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { name: Identifier(name), kind } = self;
-            c.define(name).collect(kind);
-        }
-    }
-    impl<'c> Collectible<'c> for StructKind {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            match self {
-                StructKind::Empty => {}
-                StructKind::Tuple(k) => k.collect(c),
-                StructKind::Struct(k) => k.collect(c),
-            }
-        }
-    }
-    impl<'c> Collectible<'c> for StructMember {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { vis: _, name: Identifier(name), ty } = self;
-            c.define(name).collect(ty);
-        }
-    }
-    impl<'c> Collectible<'c> for Enum {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { name: Identifier(name), kind } = self;
-            c.define(name).collect(kind);
-        }
-    }
-    impl<'c> Collectible<'c> for EnumKind {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            match self {
-                EnumKind::NoVariants => {}
-                EnumKind::Variants(v) => v.collect(c),
-            }
-        }
-    }
-    impl<'c> Collectible<'c> for Variant {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { name: Identifier(name), kind } = self;
-            c.define(name).collect(kind);
-        }
-    }
-    impl<'c> Collectible<'c> for VariantKind {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            match self {
-                VariantKind::Plain => {}
-                VariantKind::CLike(_) => {}
-                VariantKind::Tuple(v) => v.collect(c),
-                VariantKind::Struct(v) => v.collect(c),
-            }
-        }
-    }
-    impl<'c> Collectible<'c> for Impl {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { target, body } = self;
-            c.collect(target).collect(body);
-        }
-    }
-    impl<'c> Collectible<'c> for Block {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { stmts } = self;
-            for stmt in stmts {
-                stmt.collect(c);
-            }
-        }
-    }
-    impl<'c> Collectible<'c> for Stmt {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { extents, kind, semi: _ } = self;
-            c.location(extents.head).collect(kind);
-        }
-    }
-    impl<'c> Collectible<'c> for StmtKind {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            match self {
-                StmtKind::Empty => {}
-                StmtKind::Local(s) => s.collect(c),
-                StmtKind::Item(s) => s.collect(c),
-                StmtKind::Expr(s) => s.collect(c),
-            }
-        }
-    }
-    impl<'c> Collectible<'c> for Let {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { mutable: _, name: Identifier(name), ty, init } = self;
-            c.collect(init).collect(ty).define(name);
-        }
-    }
-    impl<'c> Collectible<'c> for Expr {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { extents, kind } = self;
-            c.location(extents.head).collect(kind);
-        }
-    }
-    impl<'c> Collectible<'c> for ExprKind {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            match self {
-                ExprKind::Assign(k) => k.collect(c),
-                ExprKind::Binary(k) => k.collect(c),
-                ExprKind::Unary(k) => k.collect(c),
-                ExprKind::Member(k) => k.collect(c),
-                ExprKind::Call(k) => k.collect(c),
-                ExprKind::Index(k) => k.collect(c),
-                ExprKind::Path(k) => k.collect(c),
-                ExprKind::Literal(k) => k.collect(c),
-                ExprKind::Array(k) => k.collect(c),
-                ExprKind::ArrayRep(k) => k.collect(c),
-                ExprKind::AddrOf(k) => k.collect(c),
-                ExprKind::Block(k) => k.collect(c),
-                ExprKind::Empty => {}
-                ExprKind::Group(k) => k.collect(c),
-                ExprKind::Tuple(k) => k.collect(c),
-                ExprKind::While(k) => k.collect(c),
-                ExprKind::If(k) => k.collect(c),
-                ExprKind::For(k) => k.collect(c),
-                ExprKind::Break(k) => k.collect(c),
-                ExprKind::Return(k) => k.collect(c),
-                ExprKind::Continue(k) => k.collect(c),
-            }
-        }
-    }
-    impl<'c> Collectible<'c> for Assign {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { head, op: _, tail } = self;
-            c.collect(head).collect(tail);
-        }
-    }
-    impl<'c> Collectible<'c> for Binary {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { head, tail } = self;
-            c.collect(head);
-            for (_, tail) in tail {
-                c.collect(tail);
-            }
-        }
-    }
-    impl<'c> Collectible<'c> for Unary {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { ops: _, tail } = self;
-            c.collect(tail);
-        }
-    }
-    impl<'c> Collectible<'c> for Member {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { head, tail } = self;
-            c.collect(head).collect(tail);
-        }
-    }
-    impl<'c> Collectible<'c> for Call {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { callee, args } = self;
-            c.collect(callee).collect(args);
-        }
-    }
-    impl<'c> Collectible<'c> for Tuple {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { exprs } = self;
-            c.collect(exprs);
-        }
-    }
-    impl<'c> Collectible<'c> for Index {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { head, indices } = self;
-            c.collect(head).collect(indices);
-        }
-    }
-    impl<'c> Collectible<'c> for Indices {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { exprs } = self;
-            c.collect(exprs);
-        }
-    }
-    impl<'c> Collectible<'c> for Array {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { values } = self;
-            c.collect(values);
-        }
-    }
-    impl<'c> Collectible<'c> for ArrayRep {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { value, repeat } = self;
-            c.collect(value).collect(repeat);
-        }
-    }
-    impl<'c> Collectible<'c> for AddrOf {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { count: _, mutable: _, expr } = self;
-            c.collect(expr);
-        }
-    }
-    impl<'c> Collectible<'c> for Group {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { expr } = self;
-            c.collect(expr);
-        }
-    }
-    impl<'c> Collectible<'c> for While {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { cond, pass, fail } = self;
-            c.collect(cond).collect(pass).collect(fail);
-        }
-    }
-    impl<'c> Collectible<'c> for Else {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { body } = self;
-            c.collect(body);
-        }
-    }
-    impl<'c> Collectible<'c> for If {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { cond, pass, fail } = self;
-            c.collect(cond).collect(pass).collect(fail);
-        }
-    }
-    impl<'c> Collectible<'c> for For {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { bind: Identifier(name), cond, pass, fail } = self;
-            c.collect(cond).define(name).collect(pass).collect(fail);
-        }
-    }
-    impl<'c> Collectible<'c> for Break {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { body } = self;
-            c.collect(body);
-        }
-    }
-    impl<'c> Collectible<'c> for Return {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { body } = self;
-            c.collect(body);
-        }
-    }
-    impl<'c> Collectible<'c> for Continue {
-        fn collect(&'c self, _c: &mut Collector<'c>) {}
-    }
-    impl<'c> Collectible<'c> for Literal {
-        fn collect(&'c self, _c: &mut Collector<'c>) {}
-    }
-    impl<'c> Collectible<'c> for Identifier {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self(name) = self;
-            c.reference(name);
-        }
-    }
-    impl<'c> Collectible<'c> for Param {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { mutability: _, name, ty } = self;
-            c.collect(name).collect(ty);
-        }
-    }
-    impl<'c> Collectible<'c> for Ty {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { extents, kind } = self;
-            c.location(extents.head).collect(kind);
-        }
-    }
-    impl<'c> Collectible<'c> for TyKind {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            match self {
-                TyKind::Never => {}
-                TyKind::Empty => {}
-                TyKind::SelfTy => {}
-                TyKind::Path(t) => t.collect(c),
-                TyKind::Tuple(t) => t.collect(c),
-                TyKind::Ref(t) => t.collect(c),
-                TyKind::Fn(t) => t.collect(c),
-            }
-        }
-    }
-    impl<'c> Collectible<'c> for Path {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { absolute: _, parts } = self;
-            for part in parts {
-                c.collect(part);
-            }
-        }
-    }
-    impl<'c> Collectible<'c> for PathPart {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            match self {
-                PathPart::SuperKw => {}
-                PathPart::SelfKw => {}
-                PathPart::Ident(i) => i.collect(c),
-            }
-        }
-    }
-    impl<'c> Collectible<'c> for TyTuple {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { types } = self;
-            for ty in types {
-                c.collect(ty);
-            }
-        }
-    }
-    impl<'c> Collectible<'c> for TyRef {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { count: _, to } = self;
-            c.collect(to);
-        }
-    }
-    impl<'c> Collectible<'c> for TyFn {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            let Self { args, rety } = self;
-            c.collect(args).collect(rety);
-        }
-    }
-
-    impl<'c, C: Collectible<'c> + Sized> Collectible<'c> for Vec<C> {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            for i in self {
-                c.collect(i);
-            }
-        }
-    }
-    impl<'c, C: Collectible<'c> + Sized> Collectible<'c> for Option<C> {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            if let Some(i) = self {
-                c.collect(i);
-            }
-        }
-    }
-    impl<'c, C: Collectible<'c>> Collectible<'c> for Box<C> {
-        fn collect(&'c self, c: &mut Collector<'c>) {
-            c.collect(self.as_ref());
-        }
-    }
-}

cl-repl/examples/identify_tokens.rs

@@ -1,6 +1,7 @@
 //! This example grabs input from stdin, lexes it, and prints which lexer rules matched
 #![allow(unused_imports)]
-use conlang::lexer::Lexer;
+use cl_lexer::Lexer;
+use cl_token::Token;
 use std::{
     error::Error,
     io::{stdin, IsTerminal, Read},
@@ -57,7 +58,7 @@ fn lex_tokens(file: &str, path: Option<&Path>) -> Result<(), Box<dyn Error>> {
     Ok(())
 }
 
-fn print_token(t: conlang::token::Token) {
+fn print_token(t: Token) {
     println!(
         "{:02}:{:02}: {:#19} │{}│",
         t.line(),

cl-repl/examples/typeck.rs

@@ -0,0 +1,109 @@
+use cl_lexer::Lexer;
+use cl_parser::Parser;
+use cl_repl::repline::{error::Error as RlError, Repline};
+use cl_typeck::{name_collector::NameCollector, project::Project};
+use std::error::Error;
+
+fn main() -> Result<(), Box<dyn Error>> {
+    let mut prj = Project::default();
+    let mut tcol = NameCollector::new(&mut prj);
+
+    println!(
+        "--- {} v{} 💪🦈 ---",
+        env!("CARGO_BIN_NAME"),
+        env!("CARGO_PKG_VERSION"),
+    );
+
+    read_and(
+        "\x1b[33m",
+        "cl>",
+        "? >",
+        |line| -> Result<_, Box<dyn Error>> {
+            if line.trim_start().is_empty() {
+                query(&tcol)?;
+                return Ok(Response::Deny);
+            }
+            let mut parser = Parser::new(Lexer::new(line));
+            let code = match parser.file() {
+                Ok(code) => code,
+                Err(e) => Err(e)?,
+            };
+            tcol.file(&code)?;
+            Ok(Response::Accept)
+        },
+    )
+}
+
+pub enum Response {
+    Accept,
+    Deny,
+    Break,
+}
+
+fn read_and(
+    color: &str,
+    begin: &str,
+    again: &str,
+    mut f: impl FnMut(&str) -> Result<Response, Box<dyn Error>>,
+) -> Result<(), Box<dyn Error>> {
+    let mut rl = Repline::new(color, begin, again);
+    loop {
+        let line = match rl.read() {
+            Err(RlError::CtrlC(_)) => break,
+            Err(RlError::CtrlD(line)) => {
+                rl.deny();
+                line
+            }
+            Ok(line) => line,
+            Err(e) => Err(e)?,
+        };
+        print!("\x1b[G\x1b[J");
+        match f(&line) {
+            Ok(Response::Accept) => rl.accept(),
+            Ok(Response::Deny) => rl.deny(),
+            Ok(Response::Break) => break,
+            Err(e) => print!("\x1b[40G\x1bJ\x1b[91m{e}\x1b[0m"),
+        }
+    }
+    Ok(())
+}
+
+fn query(prj: &Project) -> Result<(), Box<dyn Error>> {
+    use cl_typeck::{
+        definition::{Def, DefKind},
+        type_kind::TypeKind,
+    };
+    read_and("\x1b[35m", "qy>", "? >", |line| {
+        if line.trim_start().is_empty() {
+            return Ok(Response::Break);
+        }
+        match line {
+            "$all\n" => println!("{prj:#?}"),
+            _ => {
+                // parse it as a path, and convert the path into a borrowed path
+                let path = Parser::new(Lexer::new(line)).path()?;
+
+                let Some((type_id, path)) = prj.get_type((&path).into(), prj.module_root) else {
+                    return Ok(Response::Deny);
+                };
+                let Def { name, vis, meta: _, kind, source: _, module } = &prj[type_id];
+                match (kind, prj.get_value(path, type_id)) {
+                    (_, Some((val, path))) => {
+                        println!("value {}; {path}\n{:#?}", usize::from(val), prj[val])
+                    }
+                    (DefKind::Type(TypeKind::Module), None) => println!(
+                        "{vis}mod \"{name}\" (#{}); {path}\n{:#?}",
+                        usize::from(type_id),
+                        module
+                    ),
+                    (_, None) => println!(
+                        "type {name}(#{}); {path}\n{:#?}",
+                        usize::from(type_id),
+                        prj.pool[type_id]
+                    ),
+                };
+            }
+        }
+        Ok(Response::Accept)
+    })
+}

cl-repl/examples/yaml.rs

@@ -0,0 +1,639 @@
+//! Pretty prints a conlang AST in yaml
+
+use cl_lexer::Lexer;
+use cl_parser::Parser;
+use cl_repl::repline::{error::Error as RlError, Repline};
+use std::error::Error;
+
+fn main() -> Result<(), Box<dyn Error>> {
+    let mut rl = Repline::new("\x1b[33m", "cl>", "? >");
+    loop {
+        let line = match rl.read() {
+            Err(RlError::CtrlC(_)) => break,
+            Err(RlError::CtrlD(line)) => {
+                rl.deny();
+                line
+            }
+            Ok(line) => line,
+            Err(e) => Err(e)?,
+        };
+
+        let mut parser = Parser::new(Lexer::new(&line));
+        let code = match parser.stmt() {
+            Ok(code) => {
+                rl.accept();
+                code
+            }
+            Err(e) => {
+                print!("\x1b[40G\x1bJ\x1b[91m{e}\x1b[0m");
+                continue;
+            }
+        };
+        print!("\x1b[G\x1b[J\x1b[A");
+        Yamler::new().yaml(&code);
+        println!();
+    }
+    Ok(())
+}
+
+pub use yamler::Yamler;
+pub mod yamler {
+    use crate::yamlify::Yamlify;
+    use std::{
+        fmt::Display,
+        io::Write,
+        ops::{Deref, DerefMut},
+    };
+    #[derive(Debug, Default)]
+    pub struct Yamler {
+        depth: usize,
+    }
+
+    impl Yamler {
+        pub fn new() -> Self {
+            Self::default()
+        }
+
+        pub fn indent(&mut self) -> Section {
+            Section::new(self)
+        }
+
+        /// Prints a [Yamlify] value
+        #[inline]
+        pub fn yaml<T: Yamlify>(&mut self, yaml: &T) -> &mut Self {
+            yaml.yaml(self);
+            self
+        }
+
+        fn increase(&mut self) {
+            self.depth += 1;
+        }
+
+        fn decrease(&mut self) {
+            self.depth -= 1;
+        }
+
+        fn print_indentation(&self, writer: &mut impl Write) {
+            for _ in 0..self.depth {
+                let _ = write!(writer, "  ");
+            }
+        }
+
+        /// Prints a section header and increases indentation
+        pub fn key(&mut self, name: impl Display) -> Section {
+            println!();
+            self.print_indentation(&mut std::io::stdout().lock());
+            print!("- {name}:");
+            self.indent()
+        }
+
+        /// Prints a yaml key value pair: `- name: "value"`
+        pub fn pair<D: Display, T: Yamlify>(&mut self, name: D, value: T) -> &mut Self {
+            self.key(name).yaml(&value);
+            self
+        }
+
+        /// Prints a yaml scalar value: `"name"``
+        pub fn value<D: Display>(&mut self, value: D) -> &mut Self {
+            print!(" {value}");
+            self
+        }
+
+        pub fn list<D: Yamlify>(&mut self, list: &[D]) -> &mut Self {
+            for (idx, value) in list.iter().enumerate() {
+                self.pair(idx, value);
+            }
+            self
+        }
+    }
+
+    /// Tracks the start and end of an indented block (a "section")
+    pub struct Section<'y> {
+        yamler: &'y mut Yamler,
+    }
+
+    impl<'y> Section<'y> {
+        pub fn new(yamler: &'y mut Yamler) -> Self {
+            yamler.increase();
+            Self { yamler }
+        }
+    }
+
+    impl<'y> Deref for Section<'y> {
+        type Target = Yamler;
+        fn deref(&self) -> &Self::Target {
+            self.yamler
+        }
+    }
+    impl<'y> DerefMut for Section<'y> {
+        fn deref_mut(&mut self) -> &mut Self::Target {
+            self.yamler
+        }
+    }
+
+    impl<'y> Drop for Section<'y> {
+        fn drop(&mut self) {
+            let Self { yamler } = self;
+            yamler.decrease();
+        }
+    }
+}
+
+pub mod yamlify {
+    use super::yamler::Yamler;
+    use cl_ast::*;
+
+    pub trait Yamlify {
+        fn yaml(&self, y: &mut Yamler);
+    }
+
+    impl Yamlify for File {
+        fn yaml(&self, y: &mut Yamler) {
+            let File { items } = self;
+            y.key("File").yaml(items);
+        }
+    }
+    impl Yamlify for Visibility {
+        fn yaml(&self, y: &mut Yamler) {
+            if let Visibility::Public = self {
+                y.pair("vis", "pub");
+            }
+        }
+    }
+    impl Yamlify for Mutability {
+        fn yaml(&self, y: &mut Yamler) {
+            if let Mutability::Mut = self {
+                y.pair("mut", true);
+            }
+        }
+    }
+
+    impl Yamlify for Attrs {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { meta } = self;
+            y.key("Attrs").yaml(meta);
+        }
+    }
+    impl Yamlify for Meta {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { name, kind } = self;
+            y.key("Meta").pair("name", name).yaml(kind);
+        }
+    }
+    impl Yamlify for MetaKind {
+        fn yaml(&self, y: &mut Yamler) {
+            match self {
+                MetaKind::Plain => y,
+                MetaKind::Equals(value) => y.pair("equals", value),
+                MetaKind::Func(args) => y.pair("args", args),
+            };
+        }
+    }
+
+    impl Yamlify for Item {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { extents: _, attrs, vis, kind } = self;
+            y.key("Item").yaml(attrs).yaml(vis).yaml(kind);
+        }
+    }
+    impl Yamlify for ItemKind {
+        fn yaml(&self, y: &mut Yamler) {
+            match self {
+                ItemKind::Alias(f) => y.yaml(f),
+                ItemKind::Const(f) => y.yaml(f),
+                ItemKind::Static(f) => y.yaml(f),
+                ItemKind::Module(f) => y.yaml(f),
+                ItemKind::Function(f) => y.yaml(f),
+                ItemKind::Struct(f) => y.yaml(f),
+                ItemKind::Enum(f) => y.yaml(f),
+                ItemKind::Impl(f) => y.yaml(f),
+            };
+        }
+    }
+    impl Yamlify for Alias {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { to, from } = self;
+            y.key("Alias").pair("to", to).pair("from", from);
+        }
+    }
+    impl Yamlify for Const {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { name, ty, init } = self;
+            y.key("Const")
+                .pair("name", name)
+                .pair("ty", ty)
+                .pair("init", init);
+        }
+    }
+    impl Yamlify for Static {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { mutable, name, ty, init } = self;
+            y.key(name).yaml(mutable).pair("ty", ty).pair("init", init);
+        }
+    }
+    impl Yamlify for Module {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { name, kind } = self;
+            y.key("Module").pair("name", name).yaml(kind);
+        }
+    }
+    impl Yamlify for ModuleKind {
+        fn yaml(&self, y: &mut Yamler) {
+            match self {
+                ModuleKind::Inline(f) => y.yaml(f),
+                ModuleKind::Outline => y,
+            };
+        }
+    }
+    impl Yamlify for Function {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { name, args, body, rety } = self;
+            y.key("Function")
+                .pair("name", name)
+                .pair("args", args)
+                .pair("body", body)
+                .pair("rety", rety);
+        }
+    }
+    impl Yamlify for Struct {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { name, kind } = self;
+            y.key("Struct").pair("name", name).yaml(kind);
+        }
+    }
+    impl Yamlify for StructKind {
+        fn yaml(&self, y: &mut Yamler) {
+            match self {
+                StructKind::Empty => y,
+                StructKind::Tuple(k) => y.yaml(k),
+                StructKind::Struct(k) => y.yaml(k),
+            };
+        }
+    }
+    impl Yamlify for StructMember {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { vis, name, ty } = self;
+            y.key("StructMember").yaml(vis).pair("name", name).yaml(ty);
+        }
+    }
+    impl Yamlify for Enum {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { name, kind } = self;
+            y.key("Enum").pair("name", name).yaml(kind);
+        }
+    }
+    impl Yamlify for EnumKind {
+        fn yaml(&self, y: &mut Yamler) {
+            match self {
+                EnumKind::NoVariants => y,
+                EnumKind::Variants(v) => y.yaml(v),
+            };
+        }
+    }
+    impl Yamlify for Variant {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { name, kind } = self;
+            y.key("Variant").pair("name", name).yaml(kind);
+        }
+    }
+    impl Yamlify for VariantKind {
+        fn yaml(&self, y: &mut Yamler) {
+            match self {
+                VariantKind::Plain => y,
+                VariantKind::CLike(v) => y.yaml(v),
+                VariantKind::Tuple(v) => y.yaml(v),
+                VariantKind::Struct(v) => y.yaml(v),
+            };
+        }
+    }
+    impl Yamlify for Impl {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { target, body } = self;
+            y.key("Impl").pair("target", target).pair("body", body);
+        }
+    }
+    impl Yamlify for Block {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { stmts } = self;
+            y.key("Block").yaml(stmts);
+        }
+    }
+    impl Yamlify for Stmt {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { extents: _, kind, semi } = self;
+            y.key("Stmt").yaml(kind).yaml(semi);
+        }
+    }
+    impl Yamlify for Semi {
+        fn yaml(&self, y: &mut Yamler) {
+            if let Semi::Terminated = self {
+                y.pair("terminated", true);
+            }
+        }
+    }
+    impl Yamlify for StmtKind {
+        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;
+            y.yaml(kind);
+        }
+    }
+    impl Yamlify for ExprKind {
+        fn yaml(&self, y: &mut Yamler) {
+            match self {
+                ExprKind::Assign(k) => k.yaml(y),
+                ExprKind::Binary(k) => k.yaml(y),
+                ExprKind::Unary(k) => k.yaml(y),
+                ExprKind::Index(k) => k.yaml(y),
+                ExprKind::Path(k) => k.yaml(y),
+                ExprKind::Literal(k) => k.yaml(y),
+                ExprKind::Array(k) => k.yaml(y),
+                ExprKind::ArrayRep(k) => k.yaml(y),
+                ExprKind::AddrOf(k) => k.yaml(y),
+                ExprKind::Block(k) => k.yaml(y),
+                ExprKind::Empty => {}
+                ExprKind::Group(k) => k.yaml(y),
+                ExprKind::Tuple(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),
+            }
+        }
+    }
+    impl Yamlify for Assign {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { kind, parts } = self;
+            y.key("Assign")
+                .pair("kind", kind)
+                .pair("head", &parts.0)
+                .pair("tail", &parts.1);
+        }
+    }
+    impl Yamlify for AssignKind {
+        fn yaml(&self, y: &mut Yamler) {
+            y.value(self);
+        }
+    }
+    impl Yamlify for Binary {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { kind, parts } = self;
+            y.key("Binary")
+                .pair("kind", kind)
+                .pair("head", &parts.0)
+                .pair("tail", &parts.1);
+        }
+    }
+    impl Yamlify for BinaryKind {
+        fn yaml(&self, y: &mut Yamler) {
+            y.value(self);
+        }
+    }
+    impl Yamlify for Unary {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { kind, tail } = self;
+            y.key("Unary").pair("kind", kind).pair("tail", tail);
+        }
+    }
+    impl Yamlify for UnaryKind {
+        fn yaml(&self, y: &mut Yamler) {
+            y.value(self);
+        }
+    }
+    impl Yamlify for Tuple {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { exprs } = self;
+            y.key("Tuple").list(exprs);
+        }
+    }
+    impl Yamlify for Index {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { head, indices } = self;
+            y.key("Index").pair("head", head).list(indices);
+        }
+    }
+    impl Yamlify for Array {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { values } = self;
+            y.key("Array").list(values);
+        }
+    }
+    impl Yamlify for ArrayRep {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { value, repeat } = self;
+            y.key("ArrayRep")
+                .pair("value", value)
+                .pair("repeat", repeat);
+        }
+    }
+    impl Yamlify for AddrOf {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { count, mutable, expr } = self;
+            y.key("AddrOf")
+                .yaml(mutable)
+                .pair("count", count)
+                .pair("expr", expr);
+        }
+    }
+    impl Yamlify for Group {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { expr } = self;
+            y.key("Group").yaml(expr);
+        }
+    }
+    impl Yamlify for While {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { cond, pass, fail } = self;
+            y.key("While")
+                .pair("cond", cond)
+                .pair("pass", pass)
+                .pair("fail", fail);
+        }
+    }
+    impl Yamlify for Else {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { body } = self;
+            y.key("Else").yaml(body);
+        }
+    }
+    impl Yamlify for If {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { cond, pass, fail } = self;
+            y.key("If").pair("cond", cond).pair("pass", pass).yaml(fail);
+        }
+    }
+    impl Yamlify for For {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { bind, cond, pass, fail } = self;
+            y.key("For")
+                .pair("bind", bind)
+                .pair("cond", cond)
+                .pair("pass", pass)
+                .yaml(fail);
+        }
+    }
+    impl Yamlify for Break {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { body } = self;
+            y.key("Break").yaml(body);
+        }
+    }
+    impl Yamlify for Return {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { body } = self;
+            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}\""));
+        }
+    }
+    impl Yamlify for Identifier {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self(name) = self;
+            y.value(name);
+        }
+    }
+    impl Yamlify for Param {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { mutability, name, ty } = self;
+            y.key("Param")
+                .yaml(mutability)
+                .pair("name", name)
+                .pair("ty", ty);
+        }
+    }
+    impl Yamlify for Ty {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { extents: _, kind } = self;
+            y.key("Ty").yaml(kind);
+        }
+    }
+    impl Yamlify for TyKind {
+        fn yaml(&self, y: &mut Yamler) {
+            match self {
+                TyKind::Never => y.value("Never"),
+                TyKind::Empty => y.value("Empty"),
+                TyKind::SelfTy => y.value("Self"),
+                TyKind::Path(t) => y.yaml(t),
+                TyKind::Tuple(t) => y.yaml(t),
+                TyKind::Ref(t) => y.yaml(t),
+                TyKind::Fn(t) => y.yaml(t),
+            };
+        }
+    }
+    impl Yamlify for Path {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { absolute, parts } = self;
+            let mut y = y.key("Path");
+            if *absolute {
+                y.pair("absolute", absolute);
+            }
+            for part in parts {
+                y.pair("part", part);
+            }
+        }
+    }
+    impl Yamlify for PathPart {
+        fn yaml(&self, y: &mut Yamler) {
+            match self {
+                PathPart::SuperKw => y.value("super"),
+                PathPart::SelfKw => y.value("self"),
+                PathPart::Ident(i) => y.yaml(i),
+            };
+        }
+    }
+    impl Yamlify for TyTuple {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { types } = self;
+            let mut y = y.key("TyTuple");
+            for ty in types {
+                y.yaml(ty);
+            }
+        }
+    }
+    impl Yamlify for TyRef {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { count, to } = self;
+            y.key("TyRef").pair("count", count).pair("to", to);
+        }
+    }
+    impl Yamlify for TyFn {
+        fn yaml(&self, y: &mut Yamler) {
+            let Self { args, rety } = self;
+            y.key("TyFn").pair("args", args).pair("rety", rety);
+        }
+    }
+
+    impl<T: Yamlify> Yamlify for Option<T> {
+        fn yaml(&self, y: &mut Yamler) {
+            if let Some(v) = self {
+                y.yaml(v);
+            } else {
+                y.value("");
+            }
+        }
+    }
+    impl<T: Yamlify> Yamlify for Box<T> {
+        fn yaml(&self, y: &mut Yamler) {
+            y.yaml(&**self);
+        }
+    }
+    impl<T: Yamlify> Yamlify for Vec<T> {
+        fn yaml(&self, y: &mut Yamler) {
+            for thing in self {
+                y.yaml(thing);
+            }
+        }
+    }
+    impl Yamlify for () {
+        fn yaml(&self, _y: &mut Yamler) {}
+    }
+
+    impl<T: Yamlify> Yamlify for &T {
+        fn yaml(&self, y: &mut Yamler) {
+            (*self).yaml(y)
+        }
+    }
+
+    macro_rules! scalar {
+        ($($t:ty),*$(,)?) => {
+            $(impl Yamlify for $t {
+                fn yaml(&self, y: &mut Yamler) {
+                    y.value(self);
+                }
+            })*
+        };
+    }
+
+    scalar! {
+        bool, char, u8, u16, u32, u64, u128, usize, i8, i16, i32, i64, i128, isize, &str, String
+    }
+}

cl-repl/src/bin/conlang.rs

@@ -0,0 +1,13 @@
+use cl_repl::{cli::run, tools::is_terminal};
+use std::error::Error;
+
+fn main() -> Result<(), Box<dyn Error>> {
+    if is_terminal() {
+        println!(
+            "--- {} v{} 💪🦈 ---",
+            env!("CARGO_BIN_NAME"),
+            env!("CARGO_PKG_VERSION"),
+        );
+    }
+    run(argh::from_env())
+}

cl-repl/src/lib.rs

@@ -3,85 +3,94 @@
 //! # TODO
 //! - [ ] Readline-like line editing
 //! - [ ] Raw mode?
+#![warn(clippy::all)]
+
+pub mod ansi {
+    // ANSI color escape sequences
+    pub const ANSI_RED: &str = "\x1b[31m";
+    pub const ANSI_GREEN: &str = "\x1b[32m"; // the color of type checker mode
+    pub const ANSI_CYAN: &str = "\x1b[36m";
+    // pub const ANSI_BRIGHT_GREEN: &str = "\x1b[92m";
+    pub const ANSI_BRIGHT_BLUE: &str = "\x1b[94m";
+    pub const ANSI_BRIGHT_MAGENTA: &str = "\x1b[95m";
+    // const ANSI_BRIGHT_CYAN: &str = "\x1b[96m";
+    pub const ANSI_RESET: &str = "\x1b[0m";
+    pub const ANSI_OUTPUT: &str = "\x1b[38;5;117m";
+
+    pub const ANSI_CLEAR_LINES: &str = "\x1b[G\x1b[J";
+}
 
 pub mod args {
-    use crate::cli::Mode;
-    use std::{
-        io::{stdin, IsTerminal},
-        ops::Deref,
-        path::{Path, PathBuf},
-    };
+    use crate::tools::is_terminal;
+    use argh::FromArgs;
+    use std::{path::PathBuf, str::FromStr};
 
-    #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
+    /// The Conlang prototype debug interface
+    #[derive(Clone, Debug, FromArgs, PartialEq, Eq, PartialOrd, Ord)]
     pub struct Args {
-        pub path: Option<PathBuf>, // defaults None
-        pub repl: bool,            // defaults true if stdin is terminal
-        pub mode: Mode,            // defaults Interpret
-    }
-    const HELP: &str = "[( --repl | --no-repl )] [--mode (tokens | pretty | type | run)] [( -f | --file ) <filename>]";
+        /// the main source file
+        #[argh(positional)]
+        pub file: Option<PathBuf>,
 
-    impl Args {
-        pub fn new() -> Self {
-            Args { path: None, repl: stdin().is_terminal(), mode: Mode::Interpret }
-        }
-        pub fn parse(mut self) -> Option<Self> {
-            let mut args = std::env::args();
-            let name = args.next().unwrap_or_default();
-            let mut unknown = false;
-            while let Some(arg) = args.next() {
-                match arg.deref() {
-                    "--repl" => self.repl = true,
-                    "--no-repl" => self.repl = false,
-                    "-f" | "--file" => self.path = args.next().map(PathBuf::from),
-                    "-m" | "--mode" => {
-                        self.mode = args.next().unwrap_or_default().parse().unwrap_or_default()
-                    }
-                    arg => {
-                        eprintln!("Unknown argument: {arg}");
-                        unknown = true;
-                    }
-                }
+        /// files to include
+        #[argh(option, short = 'I')]
+        pub include: Vec<PathBuf>,
+
+        /// the Repl mode to start in
+        #[argh(option, short = 'm', default = "Default::default()")]
+        pub mode: Mode,
+
+        /// whether to start the repl (`true` or `false`)
+        #[argh(option, short = 'r', default = "is_terminal()")]
+        pub repl: bool,
+    }
+
+    /// The CLI's operating mode
+    #[derive(Clone, Copy, Debug, Default, PartialEq, Eq, PartialOrd, Ord)]
+    pub enum Mode {
+        Tokenize,
+        Beautify,
+        #[default]
+        Interpret,
+    }
+
+    impl Mode {
+        pub fn ansi_color(self) -> &'static str {
+            use super::ansi::*;
+            match self {
+                Mode::Tokenize => ANSI_BRIGHT_BLUE,
+                Mode::Beautify => ANSI_BRIGHT_MAGENTA,
+                // Mode::Resolve => ANSI_GREEN,
+                Mode::Interpret => ANSI_CYAN,
             }
-            if unknown {
-                println!("Usage: {name} {HELP}");
-                None?
-            }
-            Some(self)
-        }
-        /// Returns the path to a file, if one was specified
-        pub fn path(&self) -> Option<&Path> {
-            self.path.as_deref()
-        }
-        /// Returns whether to start a REPL session or not
-        pub fn repl(&self) -> bool {
-            self.repl
-        }
-        /// Returns the repl Mode
-        pub fn mode(&self) -> Mode {
-            self.mode
         }
     }
-    impl Default for Args {
-        fn default() -> Self {
-            Self::new()
+
+    impl FromStr for Mode {
+        type Err = &'static str;
+        fn from_str(s: &str) -> Result<Self, &'static str> {
+            Ok(match s {
+                "i" | "interpret" | "r" | "run" => Mode::Interpret,
+                "b" | "beautify" | "p" | "pretty" => Mode::Beautify,
+                // "r" | "resolve" | "typecheck" | "type" => Mode::Resolve,
+                "t" | "tokenize" | "token" => Mode::Tokenize,
+                _ => Err("Recognized modes are: 'r' \"run\", 'p' \"pretty\", 't' \"token\"")?,
+            })
         }
     }
 }
 
 pub mod program {
-    use std::{fmt::Display, io::Write};
-
-    use conlang::{
-        ast::{self, ast_impl::format::Pretty},
-        interpreter::{
-            env::Environment, error::IResult, interpret::Interpret, temp_type_impl::ConValue,
-        },
-        // pretty_printer::{PrettyPrintable, Printer},
-        lexer::Lexer,
-        parser::{error::PResult, Parser},
-        resolver::{error::TyResult, Resolver},
+    use cl_interpret::{
+        env::Environment, error::IResult, interpret::Interpret, temp_type_impl::ConValue,
     };
 
+    use cl_ast::{self as ast, format::*};
+    use cl_lexer::Lexer;
+    use cl_parser::{error::PResult, Parser};
+    // use conlang::resolver::{error::TyResult, Resolver};
+    use std::{fmt::Display, io::Write};
+
     pub struct Parsable;
 
     pub enum Parsed {
@@ -136,10 +145,6 @@ pub mod program {
             // println!("{self}")
         }
 
-        pub fn resolve(&mut self, resolver: &mut Resolver) -> TyResult<()> {
-            todo!("Program::resolve(\n{self},\n{resolver:?}\n)")
-        }
-
         pub fn run(&self, env: &mut Environment) -> IResult<ConValue> {
             match &self.data {
                 Parsed::File(v) => v.interpret(env),
@@ -155,18 +160,6 @@ pub mod program {
         //     }
         //     .map(|ty| println!("{ty}"))
         // }
-
-        // /// Runs the [Program] in the specified [Environment]
-        // pub fn run(&self, env: &mut Environment) -> IResult<()> {
-        //     println!(
-        //         "{}",
-        //         match &self.data {
-        //             Parsed::Program(start) => env.eval(start)?,
-        //             Parsed::Expr(expr) => env.eval(expr)?,
-        //         }
-        //     );
-        //     Ok(())
-        // }
     }
 
     impl<'t> Display for Program<'t, Parsed> {
@@ -178,172 +171,105 @@ pub mod program {
             }
         }
     }
-
-    // impl PrettyPrintable for Program<Parsed> {
-    //     fn visit<W: Write>(&self, p: &mut Printer<W>) -> IOResult<()> {
-    //         match &self.data {
-    //             Parsed::Program(value) => value.visit(p),
-    //             Parsed::Expr(value) => value.visit(p),
-    //         }
-    //     }
-    // }
 }
 
 pub mod cli {
-    use conlang::{interpreter::env::Environment, resolver::Resolver, token::Token};
-
+    //! Implement's the command line interface
     use crate::{
-        args::Args,
-        program::{Parsable, Parsed, Program},
-    };
-    use std::{
-        convert::Infallible,
-        error::Error,
-        path::{Path, PathBuf},
-        str::FromStr,
+        args::{Args, Mode},
+        program::{Parsable, Program},
+        repl::Repl,
+        tools::print_token,
     };
+    use cl_interpret::{env::Environment, temp_type_impl::ConValue};
+    use cl_lexer::Lexer;
+    use cl_parser::Parser;
+    use std::{error::Error, path::Path};
 
-    // ANSI color escape sequences
-    const ANSI_RED: &str = "\x1b[31m";
-    const ANSI_GREEN: &str = "\x1b[32m";
-    const ANSI_CYAN: &str = "\x1b[36m";
-    const ANSI_BRIGHT_BLUE: &str = "\x1b[94m";
-    const ANSI_BRIGHT_MAGENTA: &str = "\x1b[95m";
-    // const ANSI_BRIGHT_CYAN: &str = "\x1b[96m";
-    const ANSI_RESET: &str = "\x1b[0m";
-    const ANSI_OUTPUT: &str = "\x1b[38;5;117m";
+    /// Run the command line interface
+    pub fn run(args: Args) -> Result<(), Box<dyn Error>> {
+        let Args { file, include, mode, repl } = args;
 
-    const ANSI_CLEAR_LINES: &str = "\x1b[G\x1b[J";
-
-    #[derive(Clone, Debug)]
-    pub enum CLI {
-        Repl(Repl),
-        File { mode: Mode, path: PathBuf },
-        Stdin { mode: Mode },
-    }
-    impl From<Args> for CLI {
-        fn from(value: Args) -> Self {
-            let Args { path, repl, mode } = value;
-            match (repl, path) {
-                (true, Some(path)) => {
-                    let prog = std::fs::read_to_string(path).unwrap();
-                    let code = conlang::parser::Parser::new(conlang::lexer::Lexer::new(&prog))
-                        .file()
-                        .unwrap();
-                    let mut env = conlang::interpreter::env::Environment::new();
-                    env.eval(&code).unwrap();
-                    env.call("dump", &[])
-                        .expect("calling dump in the environment shouldn't fail");
-
-                    Self::Repl(Repl { mode, env, ..Default::default() })
-                }
-                (_, Some(path)) => Self::File { mode, path },
-                (true, None) => Self::Repl(Repl { mode, ..Default::default() }),
-                (false, None) => Self::Stdin { mode },
-            }
+        let mut env = Environment::new();
+        for path in include {
+            load_file(&mut env, path)?;
         }
-    }
-    impl CLI {
-        pub fn run(&mut self) -> Result<(), Box<dyn Error>> {
-            use std::{fs, io};
-            match self {
-                CLI::Repl(repl) => repl.repl(),
-                CLI::File { mode, ref path } => {
-                    // read file
-                    Self::no_repl(*mode, Some(path), &fs::read_to_string(path)?)
-                }
-                CLI::Stdin { mode } => {
-                    Self::no_repl(*mode, None, &io::read_to_string(io::stdin())?)
-                }
+
+        if repl {
+            if let Some(file) = file {
+                load_file(&mut env, file)?;
             }
-            Ok(())
-        }
-        fn no_repl(mode: Mode, path: Option<&Path>, code: &str) {
-            let program = Program::new(code);
+            Repl::with_env(mode, env).repl()
+        } else {
+            let code = match &file {
+                Some(file) => std::fs::read_to_string(file)?,
+                None => std::io::read_to_string(std::io::stdin())?,
+            };
+            let code = Program::new(&code);
+
             match mode {
-                Mode::Tokenize => {
-                    for token in program.lex() {
-                        if let Some(path) = path {
-                            print!("{}:", path.display());
-                        }
-                        match token {
-                            Ok(token) => print_token(&token),
-                            Err(e) => println!("{e}"),
-                        }
-                    }
-                }
-                Mode::Beautify => Self::beautify(program),
-                Mode::Resolve => Self::resolve(program, Default::default()),
-                Mode::Interpret => Self::interpret(program, Environment::new()),
-            }
-        }
-        fn beautify(program: Program<Parsable>) {
-            match program.parse() {
-                Ok(program) => program.print(),
-                Err(e) => eprintln!("{e}"),
-            };
-        }
-        fn resolve(program: Program<Parsable>, mut resolver: Resolver) {
-            let mut program = match program.parse() {
-                Ok(program) => program,
-                Err(e) => {
-                    eprintln!("{e}");
-                    return;
-                }
-            };
-            if let Err(e) = program.resolve(&mut resolver) {
-                eprintln!("{e}");
-            }
-        }
-        fn interpret(program: Program<Parsable>, mut interpreter: Environment) {
-            let program = match program.parse() {
-                Ok(program) => program,
-                Err(e) => {
-                    eprintln!("{e}");
-                    return;
-                }
-            };
-            if let Err(e) = program.run(&mut interpreter) {
-                eprintln!("{e}");
-                return;
-            }
-            if let Err(e) = interpreter.call("main", &[]) {
-                eprintln!("{e}");
-            }
+                Mode::Tokenize => tokenize(code, file),
+                Mode::Beautify => beautify(code),
+                Mode::Interpret => interpret(code, &mut env),
+            }?;
         }
+        Ok(())
     }
 
-    /// The CLI's operating mode
-    #[derive(Clone, Copy, Debug, Default, PartialEq, Eq, PartialOrd, Ord)]
-    pub enum Mode {
-        Tokenize,
-        Beautify,
-        Resolve,
-        #[default]
-        Interpret,
+    fn load_file(
+        env: &mut Environment,
+        path: impl AsRef<Path>,
+    ) -> Result<ConValue, Box<dyn Error>> {
+        let file = std::fs::read_to_string(path)?;
+        let code = Parser::new(Lexer::new(&file)).file()?;
+        env.eval(&code).map_err(Into::into)
     }
-    impl Mode {
-        pub fn ansi_color(self) -> &'static str {
-            match self {
-                Mode::Tokenize => ANSI_BRIGHT_BLUE,
-                Mode::Beautify => ANSI_BRIGHT_MAGENTA,
-                Mode::Resolve => ANSI_GREEN,
-                Mode::Interpret => ANSI_CYAN,
+
+    fn tokenize(
+        code: Program<Parsable>,
+        path: Option<impl AsRef<Path>>,
+    ) -> Result<(), Box<dyn Error>> {
+        for token in code.lex() {
+            if let Some(ref path) = path {
+                print!("{}:", path.as_ref().display());
+            }
+            match token {
+                Ok(token) => print_token(&token),
+                Err(e) => println!("{e}"),
             }
         }
+        Ok(())
     }
-    impl FromStr for Mode {
-        type Err = Infallible;
-        fn from_str(s: &str) -> Result<Self, Infallible> {
-            Ok(match s {
-                "i" | "interpret" | "run" => Mode::Interpret,
-                "b" | "beautify" | "p" | "pretty" => Mode::Beautify,
-                "r" | "resolve" | "typecheck" | "type" => Mode::Resolve,
-                "t" | "tokenize" | "tokens" => Mode::Tokenize,
-                _ => Mode::Interpret,
-            })
+
+    fn beautify(code: Program<Parsable>) -> Result<(), Box<dyn Error>> {
+        code.parse()?.print();
+        Ok(())
+    }
+
+    fn interpret(code: Program<Parsable>, env: &mut Environment) -> Result<(), Box<dyn Error>> {
+        match code.parse()?.run(env)? {
+            ConValue::Empty => {}
+            ret => println!("{ret}"),
         }
+        if env.get("main").is_ok() {
+            match env.call("main", &[])? {
+                ConValue::Empty => {}
+                ret => println!("{ret}"),
+            }
+        }
+        Ok(())
     }
+}
+
+pub mod repl {
+    use crate::{
+        ansi::*,
+        args::Mode,
+        program::{Parsable, Parsed, Program},
+        tools::print_token,
+    };
+    use cl_interpret::{env::Environment, temp_type_impl::ConValue};
+    use std::fmt::Display;
 
     /// Implements the interactive interpreter
     #[derive(Clone, Debug)]
@@ -351,8 +277,8 @@ pub mod cli {
         prompt_again: &'static str, // " ?>"
         prompt_begin: &'static str, // "cl>"
         prompt_error: &'static str, // "! >"
+        prompt_succs: &'static str, // " ->"
         env: Environment,
-        resolver: Resolver,
         mode: Mode,
     }
 
@@ -362,8 +288,8 @@ pub mod cli {
                 prompt_begin: "cl>",
                 prompt_again: " ?>",
                 prompt_error: "! >",
+                prompt_succs: " =>",
                 env: Default::default(),
-                resolver: Default::default(),
                 mode: Default::default(),
             }
         }
@@ -371,9 +297,19 @@ pub mod cli {
 
     /// Prompt functions
     impl Repl {
-        pub fn prompt_error(&self, err: &impl Error) {
+        pub fn prompt_result<T: Display, E: Display>(&self, res: Result<T, E>) {
+            match &res {
+                Ok(v) => self.prompt_succs(v),
+                Err(e) => self.prompt_error(e),
+            }
+        }
+        pub fn prompt_error(&self, err: &impl Display) {
             let Self { prompt_error: prompt, .. } = self;
-            println!("{ANSI_CLEAR_LINES}{ANSI_RED}{prompt} {err}{ANSI_RESET}",)
+            println!("{ANSI_CLEAR_LINES}{ANSI_RED}{prompt} {err}{ANSI_RESET}")
+        }
+        pub fn prompt_succs(&self, value: &impl Display) {
+            let Self { prompt_succs: _prompt, .. } = self;
+            println!("{ANSI_GREEN}{value}{ANSI_RESET}")
         }
         /// Resets the cursor to the start of the line, clears the terminal,
         /// and sets the output color
@@ -388,9 +324,14 @@ pub mod cli {
         pub fn new(mode: Mode) -> Self {
             Self { mode, ..Default::default() }
         }
+        /// Constructs a new [Repl] with the provided [Mode] and [Environment]
+        pub fn with_env(mode: Mode, env: Environment) -> Self {
+            Self { mode, env, ..Default::default() }
+        }
         /// Runs the main REPL loop
         pub fn repl(&mut self) {
             use crate::repline::{error::Error, Repline};
+
             let mut rl = Repline::new(self.mode.ansi_color(), self.prompt_begin, self.prompt_again);
             fn clear_line() {
                 print!("\x1b[G\x1b[J");
@@ -456,23 +397,26 @@ pub mod cli {
             );
         }
         fn command(&mut self, line: &str) -> bool {
-            match line.trim() {
-                "$pretty" => self.mode = Mode::Beautify,
-                "$tokens" => self.mode = Mode::Tokenize,
-                "$type" => self.mode = Mode::Resolve,
-                "$run" => self.mode = Mode::Interpret,
-                "$mode" => println!("{:?} Mode", self.mode),
-                "$help" => self.help(),
-                _ => return false,
+            let Some(line) = line.trim().strip_prefix('$') else {
+                return false;
+            };
+            if let Ok(mode) = line.parse() {
+                self.mode = mode;
+            } else {
+                match line {
+                    "$run" => self.mode = Mode::Interpret,
+                    "mode" => println!("{:?} Mode", self.mode),
+                    "help" => self.help(),
+                    _ => return false,
+                }
             }
             true
         }
         /// Dispatches calls to repl functions based on the program
         fn dispatch(&mut self, code: &mut Program<Parsed>) {
             match self.mode {
-                Mode::Tokenize => (),
+                Mode::Tokenize => {}
                 Mode::Beautify => self.beautify(code),
-                Mode::Resolve => self.typecheck(code),
                 Mode::Interpret => self.interpret(code),
             }
         }
@@ -485,21 +429,22 @@ pub mod cli {
             }
         }
         fn interpret(&mut self, code: &Program<Parsed>) {
-            if let Err(e) = code.run(&mut self.env) {
-                self.prompt_error(&e)
-            }
-        }
-        fn typecheck(&mut self, code: &mut Program<Parsed>) {
-            if let Err(e) = code.resolve(&mut self.resolver) {
-                self.prompt_error(&e)
+            match code.run(&mut self.env) {
+                Ok(ConValue::Empty) => {}
+                res => self.prompt_result(res),
             }
         }
         fn beautify(&mut self, code: &Program<Parsed>) {
             code.print()
         }
     }
+}
 
-    fn print_token(t: &Token) {
+pub mod tools {
+    use cl_token::Token;
+    use std::io::IsTerminal;
+    /// Prints a token in the particular way cl-repl does
+    pub fn print_token(t: &Token) {
         println!(
             "{:02}:{:02}: {:#19} │{}│",
             t.line(),
@@ -508,6 +453,10 @@ pub mod cli {
             t.data(),
         )
     }
+    /// gets whether stdin AND stdout are a terminal, for pipelining
+    pub fn is_terminal() -> bool {
+        std::io::stdin().is_terminal() && std::io::stdout().is_terminal()
+    }
 }
 
 pub mod repline;

cl-repl/src/main.rs

@@ -1,6 +0,0 @@
-use cl_repl::{args::Args, cli::CLI};
-use std::error::Error;
-
-fn main() -> Result<(), Box<dyn Error>> {
-    CLI::from(Args::new().parse().unwrap_or_default()).run()
-}

cl-repl/src/repline.rs

@@ -49,7 +49,7 @@ pub mod ignore {
     /// # Examples
     /// ```rust
     /// #![deny(unused_must_use)]
-    /// # use cl_frontend::repline::ignore::Ignore;
+    /// # use cl_repl::repline::ignore::Ignore;
     /// ().ignore();
     /// Err::<(), &str>("Foo").ignore();
     /// Some("Bar").ignore();

cl-structures/Cargo.toml

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

cl-structures/src/intern_pool.rs

@@ -0,0 +1,131 @@
+//! Trivially-copyable, easily comparable typed indices, and a [Pool] to contain them
+//!
+//! # Examples
+//!
+//! ```rust
+//! # use cl_structures::intern_pool::*;
+//! // first, create a new InternKey type (this ensures type safety)
+//! make_intern_key!{
+//!     NumbersKey
+//! }
+//!
+//! // then, create a pool with that type
+//! let mut numbers: Pool<i32, NumbersKey> = Pool::new();
+//! let first = numbers.insert(1);
+//! let second = numbers.insert(2);
+//! let third = numbers.insert(3);
+//!
+//! // You can access elements immutably with `get`
+//! assert_eq!(Some(&3), numbers.get(third));
+//! assert_eq!(Some(&2), numbers.get(second));
+//! // or by indexing
+//! assert_eq!(1, numbers[first]);
+//!
+//! // Or mutably
+//! *numbers.get_mut(first).unwrap() = 100000;
+//!
+//! assert_eq!(Some(&100000), numbers.get(first));
+//! ```
+
+/// Creates newtype indices over [`usize`] for use as [Pool] keys.
+#[macro_export]
+macro_rules! make_intern_key {($($(#[$meta:meta])* $name:ident),*$(,)?) => {$(
+    $(#[$meta])*
+    #[repr(transparent)]
+    #[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+    pub struct $name(usize);
+
+    impl $crate::intern_pool::InternKey for $name {
+        #[doc = concat!("Constructs a [`", stringify!($name), "`] from a [`usize`] without checking bounds.\n")]
+        /// # Safety
+        ///
+        /// The provided value should be within the bounds of its associated container
+        unsafe fn from_raw_unchecked(value: usize) -> Self {
+            Self(value)
+        }
+        fn get(&self) -> usize {
+            self.0
+        }
+    }
+    impl From< $name > for usize {
+        fn from(value: $name) -> Self {
+            value.0
+        }
+    }
+)*}}
+use std::ops::{Index, IndexMut};
+
+pub use make_intern_key;
+
+/// An index into a [Pool]. For full type-safety,
+/// there should be a unique [InternKey] for each [Pool]
+pub trait InternKey: std::fmt::Debug {
+    /// Constructs an [`InternKey`] from a [`usize`] without checking bounds.
+    ///
+    /// # Safety
+    ///
+    /// The provided value should be within the bounds of its associated container.
+    // ID::from_raw_unchecked here isn't *actually* unsafe, since bounds should always be
+    // checked, however, the function has unverifiable preconditions.
+    unsafe fn from_raw_unchecked(value: usize) -> Self;
+    /// Gets the index of the [`InternKey`] by value
+    fn get(&self) -> usize;
+}
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct Pool<T, ID: InternKey> {
+    pool: Vec<T>,
+    id_type: std::marker::PhantomData<ID>,
+}
+
+impl<T, ID: InternKey> Pool<T, ID> {
+    pub fn new() -> Self {
+        Self::default()
+    }
+    pub fn get(&self, index: ID) -> Option<&T> {
+        self.pool.get(index.get())
+    }
+    pub fn get_mut(&mut self, index: ID) -> Option<&mut T> {
+        self.pool.get_mut(index.get())
+    }
+
+    pub fn iter(&self) -> impl Iterator<Item = &T> {
+        self.pool.iter()
+    }
+    pub fn iter_mut(&mut self) -> impl Iterator<Item = &mut T> {
+        self.pool.iter_mut()
+    }
+
+    pub fn insert(&mut self, value: T) -> ID {
+        let id = self.pool.len();
+        self.pool.push(value);
+
+        // Safety: value was pushed to `self.pool[id]`
+        unsafe { ID::from_raw_unchecked(id) }
+    }
+}
+
+impl<T, ID: InternKey> Default for Pool<T, ID> {
+    fn default() -> Self {
+        Self { pool: vec![], id_type: std::marker::PhantomData }
+    }
+}
+
+impl<T, ID: InternKey> Index<ID> for Pool<T, ID> {
+    type Output = T;
+
+    fn index(&self, index: ID) -> &Self::Output {
+        match self.pool.get(index.get()) {
+            None => panic!("Index {:?} out of bounds in pool!", index),
+            Some(value) => value,
+        }
+    }
+}
+impl<T, ID: InternKey> IndexMut<ID> for Pool<T, ID> {
+    fn index_mut(&mut self, index: ID) -> &mut Self::Output {
+        match self.pool.get_mut(index.get()) {
+            None => panic!("Index {:?} out of bounds in pool!", index),
+            Some(value) => value,
+        }
+    }
+}

cl-structures/src/lib.rs

@@ -0,0 +1,14 @@
+//! # Universally useful structures
+//! - [Span](struct@span::Span): Stores a start and end [Loc](struct@span::Loc)
+//! - [Loc](struct@span::Loc): Stores the index in a stream
+#![warn(clippy::all)]
+#![feature(inline_const, dropck_eyepatch, decl_macro)]
+#![deny(unsafe_op_in_unsafe_fn)]
+
+pub mod span;
+
+pub mod tree;
+
+pub mod stack;
+
+pub mod intern_pool;

cl-structures/src/span.rs

@@ -1,8 +1,6 @@
-//! # Universally useful structures
 //! - [struct@Span]: Stores the start and end [struct@Loc] of a notable AST node
 //! - [struct@Loc]: Stores the line/column of a notable AST node
 #![allow(non_snake_case)]
-use crate::lexer::Lexer;
 
 /// Stores the start and end [locations](struct@Loc) within the token stream
 #[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
@@ -38,9 +36,3 @@ impl std::fmt::Display for Loc {
         write!(f, "{line}:{col}:")
     }
 }
-
-impl<'t> From<&Lexer<'t>> for Loc {
-    fn from(value: &Lexer<'t>) -> Self {
-        Loc(value.line(), value.col())
-    }
-}

cl-structures/src/stack.rs

@@ -0,0 +1,747 @@
+//! A contiguous collection with constant capacity.
+//!
+//! Since the capacity of a [Stack] may be [*known at compile time*](Sized),
+//! it may live on the call stack.
+//!
+//!
+//! # Examples
+//!
+//! Unlike a [Vec], the [Stack] doesn't grow when it reaches capacity.
+//! ```should_panic
+//! # use cl_structures::stack::*;
+//! let mut v = stack![1];
+//! v.push("This should work");
+//! v.push("This will panic!");
+//! ```
+//! To get around this limitation, the methods [try_push](Stack::try_push) and
+//! [try_insert](Stack::try_insert) are provided:
+//! ```
+//! # use cl_structures::stack::*;
+//! let mut v = stack![1];
+//! v.push("This should work");
+//! v.try_push("This should produce an err").unwrap_err();
+//! ```
+//!
+//! As the name suggests, a [Stack] enforces a stack discipline:
+//! ```
+//! # use cl_structures::stack::*;
+//! let mut v = stack![100];
+//!
+//! assert_eq!(100, v.capacity());
+//! assert_eq!(0, v.len());
+//!
+//! // Elements are pushed one at a time onto the stack
+//! v.push("foo");
+//! v.push("bar");
+//! assert_eq!(2, v.len());
+//!
+//! // The stack can be used anywhere a slice is expected
+//! assert_eq!(Some(&"foo"), v.get(0));
+//! assert_eq!(Some(&"bar"), v.last());
+//!
+//! // Elements are popped from the stack in reverse order
+//! assert_eq!(Some("bar"), v.pop());
+//! assert_eq!(Some("foo"), v.pop());
+//! assert_eq!(None, v.pop());
+//! ```
+
+// yar har! here there be unsafe code! Tread carefully.
+
+use core::slice;
+use std::{
+    fmt::Debug,
+    marker::PhantomData,
+    mem::{ManuallyDrop, MaybeUninit},
+    ops::{Deref, DerefMut},
+    ptr,
+};
+
+/// Creates a [`stack`] containing the arguments
+///
+/// # Examples
+///
+/// Creates a *full* [`Stack`] containing a list of elements
+/// ```
+/// # use cl_structures::stack::stack;
+/// let mut v = stack![1, 2, 3];
+///
+/// assert_eq!(Some(3), v.pop());
+/// assert_eq!(Some(2), v.pop());
+/// assert_eq!(Some(1), v.pop());
+/// assert_eq!(None, v.pop());
+/// ```
+///
+/// Creates a *full* [`Stack`] from a given element and size
+/// ```
+/// # use cl_structures::stack::stack;
+/// let mut v = stack![1; 2];
+///
+/// assert_eq!(Some(1), v.pop());
+/// assert_eq!(Some(1), v.pop());
+/// assert_eq!(None, v.pop());
+/// ```
+///
+/// Creates an *empty* [`Stack`] from a given size
+/// ```
+/// # use cl_structures::stack::{Stack, stack};
+/// let mut v = stack![10];
+///
+/// assert_eq!(0, v.len());
+/// assert_eq!(10, v.capacity());
+///
+/// v.push(10);
+/// assert_eq!(Some(&10), v.last());
+/// ```
+pub macro stack {
+    ($count:literal) => {
+        Stack::<_, $count>::new()
+    },
+    ($value:expr ; $count:literal) => {{
+        let mut stack: Stack<_, $count> = Stack::new();
+        for _ in 0..$count {
+            stack.push($value)
+        }
+        stack
+    }},
+    ($($values:expr),* $(,)?) => {
+        Stack::from([$($values),*])
+    }
+}
+
+/// A contiguous collection with constant capacity
+pub struct Stack<T, const N: usize> {
+    _data: PhantomData<T>,
+    buf: [MaybeUninit<T>; N],
+    len: usize,
+}
+
+impl<T: Clone, const N: usize> Clone for Stack<T, N> {
+    fn clone(&self) -> Self {
+        let mut new = Self::new();
+        for value in self.iter() {
+            new.push(value.clone())
+        }
+        new
+    }
+}
+
+impl<T: Debug, const N: usize> Debug for Stack<T, N> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_list().entries(self.iter()).finish()
+    }
+}
+
+impl<T, const N: usize> Default for Stack<T, N> {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl<T, const N: usize> Deref for Stack<T, N> {
+    type Target = [T];
+
+    #[inline]
+    fn deref(&self) -> &Self::Target {
+        // Safety:
+        // - We have ensured all elements from 0 to len have been initialized
+        // - self.elem[0] came from a reference, and so is aligned to T
+        // unsafe { &*(&self.buf[0..self.len] as *const [_] as *const [T]) }
+        unsafe { slice::from_raw_parts(self.buf.as_ptr().cast(), self.len) }
+    }
+}
+
+impl<T, const N: usize> DerefMut for Stack<T, N> {
+    #[inline]
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        // Safety:
+        // - See Deref
+        unsafe { slice::from_raw_parts_mut(self.buf.as_mut_ptr().cast(), self.len) }
+    }
+}
+
+// requires dropck-eyepatch for elements with contravariant lifetimes
+unsafe impl<#[may_dangle] T, const N: usize> Drop for Stack<T, N> {
+    #[inline]
+    fn drop(&mut self) {
+        // Safety: We have ensured that all elements in the list are
+        unsafe { core::ptr::drop_in_place(self.as_mut_slice()) };
+    }
+}
+
+impl<T, const N: usize> Extend<T> for Stack<T, N> {
+    fn extend<I: IntoIterator<Item = T>>(&mut self, iter: I) {
+        for value in iter {
+            self.push(value)
+        }
+    }
+}
+
+impl<T, const N: usize> From<[T; N]> for Stack<T, N> {
+    fn from(value: [T; N]) -> Self {
+        let value = ManuallyDrop::new(value);
+        if std::mem::size_of::<[T; N]>() == 0 {
+            // Safety: since [T; N] is zero-sized, and there are no other fields,
+            // it should be okay to interpret N as Self
+            unsafe { ptr::read(&N as *const _ as *const _) }
+        } else {
+            // Safety:
+            // - `value` is ManuallyDrop, so its destructor won't run
+            // - All elements are assumed to be initialized (so len is N)
+            Self {
+                buf: unsafe { ptr::read(&value as *const _ as *const _) },
+                len: N,
+                ..Default::default()
+            }
+        }
+    }
+}
+
+impl<T, const N: usize> Stack<T, N> {
+    /// Constructs a new, empty [Stack]
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use cl_structures::stack::Stack;
+    /// let mut v: Stack<_, 3> = Stack::new();
+    ///
+    /// v.try_push(1).unwrap();
+    /// v.try_push(2).unwrap();
+    /// v.try_push(3).unwrap();
+    /// // Trying to push a 4th element will fail, and return the failed element
+    /// assert_eq!(4, v.try_push(4).unwrap_err());
+    ///
+    /// assert_eq!(Some(3), v.pop());
+    /// ```
+    pub const fn new() -> Self {
+        Self { buf: [const { MaybeUninit::uninit() }; N], len: 0, _data: PhantomData }
+    }
+
+    /// Constructs a new [Stack] from an array of [`MaybeUninit<T>`] and an initialized length
+    ///
+    /// # Safety
+    ///
+    /// - Elements from `0..len` must be initialized
+    /// - len must not exceed the length of the array
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use cl_structures::stack::Stack;
+    /// # use core::mem::MaybeUninit;
+    /// let mut v = unsafe { Stack::from_raw_parts([MaybeUninit::new(100)], 1) };
+    ///
+    /// assert_eq!(1, v.len());
+    /// assert_eq!(1, v.capacity());
+    /// assert_eq!(Some(100), v.pop());
+    /// assert_eq!(None, v.pop());
+    /// ```
+    pub const unsafe fn from_raw_parts(buf: [MaybeUninit<T>; N], len: usize) -> Self {
+        Self { buf, len, _data: PhantomData }
+    }
+
+    /// Converts a [Stack] into an array of [`MaybeUninit<T>`] and the initialized length
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use cl_structures::stack::Stack;
+    /// let mut v: Stack<_, 10> = Stack::new();
+    /// v.push(0);
+    /// v.push(1);
+    ///
+    /// let (buf, len) = v.into_raw_parts();
+    ///
+    /// assert_eq!(0, unsafe { buf[0].assume_init() });
+    /// assert_eq!(1, unsafe { buf[1].assume_init() });
+    /// assert_eq!(2, len);
+    /// ```
+    #[inline]
+    pub fn into_raw_parts(self) -> ([MaybeUninit<T>; N], usize) {
+        let this = ManuallyDrop::new(self);
+        // Safety: since
+        (unsafe { ptr::read(&this.buf) }, this.len)
+    }
+
+    /// Returns a raw pointer to the stack's buffer
+    pub const fn as_ptr(&self) -> *const T {
+        self.buf.as_ptr().cast()
+    }
+
+    /// Returns an unsafe mutable pointer to the stack's buffer
+    pub fn as_mut_ptr(&mut self) -> *mut T {
+        self.buf.as_mut_ptr().cast()
+    }
+
+    /// Extracts a slice containing the entire vector
+    pub fn as_slice(&self) -> &[T] {
+        self
+    }
+
+    /// Extracts a mutable slice containing the entire vector
+    pub fn as_mut_slice(&mut self) -> &mut [T] {
+        self
+    }
+
+    /// Returns the total number of elements the stack can hold
+    pub const fn capacity(&self) -> usize {
+        N
+    }
+
+    /// Moves an existing stack into an allocation of a (potentially) different size,
+    /// truncating if necessary.
+    ///
+    /// This can be used to easily construct a half-empty stack
+    ///
+    /// # Examples
+    ///
+    /// You can grow a stack to fit more elements
+    /// ```
+    /// # use cl_structures::stack::Stack;
+    /// let v = Stack::from([0, 1, 2, 3, 4]);
+    /// assert_eq!(5, v.capacity());
+    ///
+    /// let mut v = v.resize::<10>();
+    /// assert_eq!(10, v.capacity());
+    ///
+    /// v.push(5);
+    /// ```
+    ///
+    /// You can truncate a stack, dropping elements off the end
+    /// ```
+    /// # use cl_structures::stack::Stack;
+    /// let v = Stack::from([0, 1, 2, 3, 4, 5, 6, 7]);
+    /// assert_eq!(8, v.capacity());
+    ///
+    /// let v = v.resize::<5>();
+    /// assert_eq!(5, v.capacity());
+    /// ```
+    pub fn resize<const M: usize>(mut self) -> Stack<T, M> {
+        // Drop elements until new length is reached
+        while self.len > M {
+            drop(self.pop());
+        }
+        let (old, len) = self.into_raw_parts();
+        let mut new: Stack<T, M> = Stack::new();
+
+        // Safety:
+        // - new and old are separate allocations
+        // - len <= M
+        unsafe {
+            ptr::copy_nonoverlapping(old.as_ptr(), new.buf.as_mut_ptr(), len);
+        }
+
+        new.len = len;
+        new
+    }
+
+    /// Push a new element onto the end of the stack
+    ///
+    /// # May Panic
+    ///
+    /// Panics if the new length exceeds capacity
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use cl_structures::stack::Stack;
+    /// let mut v: Stack<_, 4> = Stack::new();
+    ///
+    /// v.push(0);
+    /// v.push(1);
+    /// v.push(2);
+    /// v.push(3);
+    /// assert_eq!(&[0, 1, 2, 3], v.as_slice());
+    /// ```
+    pub fn push(&mut self, value: T) {
+        if self.len >= N {
+            panic!("Attempted to push into full stack")
+        }
+        // Safety: len is confirmed to be less than capacity
+        unsafe { self.push_unchecked(value) };
+    }
+
+    /// Push a new element onto the end of the stack
+    ///
+    /// Returns [`Err(value)`](Result::Err) if the new length would exceed capacity
+    pub fn try_push(&mut self, value: T) -> Result<(), T> {
+        if self.len >= N {
+            return Err(value);
+        }
+        // Safety: len is confirmed to be less than capacity
+        unsafe { self.push_unchecked(value) };
+        Ok(())
+    }
+
+    /// Push a new element onto the end of the stack, without checking capacity
+    ///
+    /// # Safety
+    ///
+    /// len after push must not exceed capacity N
+    #[inline]
+    unsafe fn push_unchecked(&mut self, value: T) {
+        unsafe { ptr::write(self.as_mut_ptr().add(self.len), value) }
+        self.len += 1; // post inc
+    }
+
+    /// Pops the last element off the end of the stack, and returns it
+    ///
+    /// Returns None if the stack is empty
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use cl_structures::stack::Stack;
+    /// let mut v = Stack::from([0, 1, 2, 3]);
+    ///
+    /// assert_eq!(Some(3), v.pop());
+    /// assert_eq!(Some(2), v.pop());
+    /// assert_eq!(Some(1), v.pop());
+    /// assert_eq!(Some(0), v.pop());
+    /// assert_eq!(None, v.pop());
+    /// ```
+    pub fn pop(&mut self) -> Option<T> {
+        if self.len == 0 {
+            None
+        } else {
+            self.len -= 1;
+            // Safety: MaybeUninit<T> implies ManuallyDrop<T>,
+            // therefore should not get dropped twice
+            Some(unsafe { ptr::read(self.as_ptr().add(self.len).cast()) })
+        }
+    }
+
+    /// Removes and returns the element at the given index,
+    /// shifting other elements toward the start
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use cl_structures::stack::Stack;
+    /// let mut v = Stack::from([0, 1, 2, 3, 4]);
+    ///
+    /// assert_eq!(2, v.remove(2));
+    /// assert_eq!(&[0, 1, 3, 4], v.as_slice());
+    /// ```
+    pub fn remove(&mut self, index: usize) -> T {
+        if index >= self.len {
+            panic!("Index {index} exceeded length {}", self.len)
+        }
+        let len = self.len - 1;
+        let base = self.as_mut_ptr();
+        let out = unsafe { ptr::read(base.add(index)) };
+
+        unsafe { ptr::copy(base.add(index + 1), base.add(index), len - index) };
+        self.len = len;
+        out
+    }
+
+    /// Removes and returns the element at the given index,
+    /// swapping it with the last element.
+    ///
+    /// # May Panic
+    ///
+    /// Panics if `index >= len`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use cl_structures::stack::Stack;
+    /// let mut v = Stack::from([0, 1, 2, 3, 4]);
+    ///
+    /// assert_eq!(2, v.swap_remove(2));
+    ///
+    /// assert_eq!(&[0, 1, 4, 3], v.as_slice());
+    /// ```
+    pub fn swap_remove(&mut self, index: usize) -> T {
+        if index >= self.len {
+            panic!("Index {index} exceeds length {}", self.len);
+        }
+        let len = self.len - 1;
+        let ptr = self.as_mut_ptr();
+        let out = unsafe { ptr::read(ptr.add(index)) };
+
+        unsafe { ptr::copy(ptr.add(len), ptr.add(index), 1) };
+        self.len = len;
+        out
+    }
+
+    /// Inserts an element at position `index` in the stack,
+    /// shifting all elements after it to the right.
+    ///
+    /// # May Panic
+    ///
+    /// Panics if `index > len` or [`self.is_full()`](Stack::is_full)
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use cl_structures::stack::Stack;
+    /// let mut v = Stack::from([0, 1, 2, 3, 4]).resize::<6>();
+    ///
+    /// v.insert(3, 0xbeef);
+    /// assert_eq!(&[0, 1, 2, 0xbeef, 3, 4], v.as_slice());
+    /// ```
+    pub fn insert(&mut self, index: usize, data: T) {
+        if index > self.len {
+            panic!("Index {index} exceeded length {}", self.len)
+        }
+        if self.is_full() {
+            panic!("Attempted to insert into full stack")
+        }
+        unsafe { self.insert_unchecked(index, data) };
+    }
+
+    /// Attempts to insert an element at position `index` in the stack,
+    /// shifting all elements after it to the right.
+    ///
+    /// If the stack is at capacity, returns the original element and an [InsertFailed] error.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use cl_structures::stack::Stack;
+    /// let mut v: Stack<_, 2> = Stack::new();
+    ///
+    /// assert_eq!(Ok(()), v.try_insert(0, 0));
+    /// ```
+    pub fn try_insert(&mut self, index: usize, data: T) -> Result<(), (T, InsertFailed<N>)> {
+        if index > self.len {
+            return Err((data, InsertFailed::Bounds(index)));
+        }
+        if self.is_full() {
+            return Err((data, InsertFailed::Full));
+        }
+        // Safety: index < self.len && !self.is_full()
+        unsafe { self.insert_unchecked(index, data) };
+        Ok(())
+    }
+
+    /// # Safety:
+    /// - index must be less than self.len
+    /// - length after insertion must be <= N
+    #[inline]
+    unsafe fn insert_unchecked(&mut self, index: usize, data: T) {
+        let base = self.as_mut_ptr();
+
+        unsafe { ptr::copy(base.add(index), base.add(index + 1), self.len - index) }
+
+        self.len += 1;
+        self.buf[index] = MaybeUninit::new(data);
+    }
+
+    /// Clears the stack
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use cl_structures::stack::Stack;
+    ///
+    /// let mut v = Stack::from([0, 1, 2, 3, 4]);
+    /// assert_eq!(v.as_slice(), &[0, 1, 2, 3, 4]);
+    ///
+    /// v.clear();
+    /// assert_eq!(v.as_slice(), &[]);
+    /// ```
+    pub fn clear(&mut self) {
+        // Hopefully copy elision takes care of this lmao
+        drop(std::mem::take(self))
+    }
+
+    /// Returns the number of elements in the stack
+    /// ```
+    /// # use cl_structures::stack::*;
+    /// let v = Stack::from([0, 1, 2, 3, 4]);
+    ///
+    /// assert_eq!(5, v.len());
+    /// ```
+    pub fn len(&self) -> usize {
+        self.len
+    }
+
+    /// Returns true if the stack is at (or over) capacity
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use cl_structures::stack::*;
+    /// let v = Stack::from([(); 10]);
+    ///
+    /// assert!(v.is_full());
+    /// ```
+    #[inline]
+    pub fn is_full(&self) -> bool {
+        self.len >= N
+    }
+
+    /// Returns true if the stack contains no elements
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use cl_structures::stack::*;
+    /// let v: Stack<(), 10> = Stack::new();
+    ///
+    /// assert!(v.is_empty());
+    /// ```
+    #[inline]
+    pub fn is_empty(&self) -> bool {
+        self.len == 0
+    }
+}
+
+#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub enum InsertFailed<const N: usize> {
+    Bounds(usize),
+    Full,
+}
+impl<const N: usize> std::error::Error for InsertFailed<N> {}
+impl<const N: usize> std::fmt::Display for InsertFailed<N> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            InsertFailed::Bounds(idx) => write!(f, "Index {idx} exceeded length {N}"),
+            InsertFailed::Full => {
+                write!(f, "Attempt to insert into full stack (length {N})")
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    #[test]
+    fn zero_sized() {
+        let v: Stack<(), { usize::MAX }> = Stack::new();
+        assert_eq!(usize::MAX, v.capacity());
+        assert_eq!(std::mem::size_of::<usize>(), std::mem::size_of_val(&v))
+    }
+    #[test]
+    #[cfg_attr(debug_assertions, ignore = "calls ().drop() usize::MAX times")]
+    fn from_usize_max_zst_array() {
+        let mut v = Stack::from([(); usize::MAX]);
+        assert_eq!(v.len(), usize::MAX);
+        v.pop();
+        assert_eq!(v.len(), usize::MAX - 1);
+    }
+    #[test]
+    fn new() {
+        let v: Stack<(), 255> = Stack::new();
+        assert_eq!(0, v.len());
+        assert_eq!(255, v.capacity());
+    }
+
+    #[test]
+    fn push() {
+        let mut v: Stack<_, 64> = Stack::new();
+        v.push(10);
+    }
+
+    #[test]
+    #[should_panic = "Attempted to push into full stack"]
+    fn push_overflow() {
+        let mut v = Stack::from([]);
+        v.push(10);
+    }
+
+    #[test]
+    fn pop() {
+        let mut v = Stack::from([1, 2, 3, 4, 5, 6, 7, 8, 9]);
+        assert_eq!(Some(9), v.pop());
+        assert_eq!(Some(8), v.pop());
+        assert_eq!(Some(7), v.pop());
+        assert_eq!(Some(6), v.pop());
+        assert_eq!(Some(5), v.pop());
+        assert_eq!(Some(4), v.pop());
+        assert_eq!(Some(3), v.pop());
+        assert_eq!(Some(2), v.pop());
+        assert_eq!(Some(1), v.pop());
+        assert_eq!(None, v.pop());
+    }
+
+    #[test]
+    fn resize_smaller() {
+        let v = Stack::from([1, 2, 3, 4, 5, 6, 7, 8, 9]);
+        let mut v = v.resize::<2>();
+
+        assert_eq!(2, v.capacity());
+
+        assert_eq!(Some(2), v.pop());
+        assert_eq!(Some(1), v.pop());
+        assert_eq!(None, v.pop());
+    }
+
+    #[test]
+    fn resize_bigger() {
+        let v = Stack::from([1, 2, 3, 4]);
+        let mut v: Stack<_, 10> = v.resize();
+
+        assert_eq!(Some(4), v.pop());
+        assert_eq!(Some(3), v.pop());
+        assert_eq!(Some(2), v.pop());
+        assert_eq!(Some(1), v.pop());
+        assert_eq!(None, v.pop());
+    }
+    #[test]
+    fn dangle() {
+        let mut v: Stack<_, 2> = Stack::new();
+        let a = 0;
+        let b = 1;
+        v.push(&a);
+        v.push(&b);
+        println!("{v:?}");
+    }
+    #[test]
+    fn remove() {
+        let mut v = Stack::from([0, 1, 2, 3, 4, 5]);
+
+        assert_eq!(3, v.remove(3));
+        assert_eq!(4, v.remove(3));
+        assert_eq!(5, v.remove(3));
+        assert_eq!(Some(2), v.pop());
+        assert_eq!(Some(1), v.pop());
+        assert_eq!(Some(0), v.pop());
+        assert_eq!(None, v.pop());
+    }
+
+    #[test]
+    fn swap_remove() {
+        let mut v = Stack::from([0, 1, 2, 3, 4, 5]);
+        assert_eq!(3, v.swap_remove(3));
+        assert_eq!(&[0, 1, 2, 5, 4], v.as_slice());
+    }
+    #[test]
+    fn swap_remove_last() {
+        let mut v = Stack::from([0, 1, 2, 3, 4, 5]);
+        assert_eq!(5, v.swap_remove(5));
+        assert_eq!(&[0, 1, 2, 3, 4], v.as_slice())
+    }
+
+    #[test]
+    fn insert() {
+        let mut v = Stack::from([0, 1, 2, 4, 5, 0x41414141]);
+        v.pop();
+        v.insert(3, 3);
+
+        assert_eq!(&[0, 1, 2, 3, 4, 5], v.as_slice())
+    }
+
+    #[test]
+    #[should_panic = "Attempted to insert into full stack"]
+    fn insert_overflow() {
+        let mut v = Stack::from([0]);
+        v.insert(0, 1);
+    }
+
+    #[test]
+    fn drop() {
+        let v = Stack::from([
+            Box::new(0),
+            Box::new(1),
+            Box::new(2),
+            Box::new(3),
+            Box::new(4),
+        ]);
+        std::mem::drop(std::hint::black_box(v));
+    }
+}

cl-structures/src/tree.rs

@@ -0,0 +1,221 @@
+//! An insert-only unordered tree, backed by a [Vec]
+//!
+//! # Examples
+//! ```
+//! use cl_structures::tree::{Tree, Node};
+//! // A tree can be created
+//! let mut tree = Tree::new();
+//! // Provided with a root node
+//! let root = tree.root("This is the root node").unwrap();
+//!
+//! // Nodes can be accessed by indexing
+//! assert_eq!(*tree[root].as_ref(), "This is the root node");
+//! // Nodes' data can be accessed directly by calling `get`/`get_mut`
+//! assert_eq!(tree.get(root).unwrap(), &"This is the root node")
+//! ```
+
+// TODO: implement an Entry-style API for doing traversal algorithms
+
+pub use self::tree_ref::Ref;
+use std::ops::{Index, IndexMut};
+
+pub mod tree_ref;
+
+/// An insert-only unordered tree, backed by a [Vec]
+#[derive(Debug)]
+pub struct Tree<T> {
+    nodes: Vec<Node<T>>,
+}
+
+impl<T> Default for Tree<T> {
+    fn default() -> Self {
+        Self { nodes: Default::default() }
+    }
+}
+
+/// Getters
+impl<T> Tree<T> {
+    pub fn get(&self, index: Ref<T>) -> Option<&T> {
+        self.get_node(index).map(|node| &node.value)
+    }
+    pub fn get_mut(&mut self, index: Ref<T>) -> Option<&mut T> {
+        self.get_node_mut(index).map(|node| &mut node.value)
+    }
+    pub fn get_node(&self, index: Ref<T>) -> Option<&Node<T>> {
+        self.nodes.get(usize::from(index))
+    }
+    pub fn get_node_mut(&mut self, index: Ref<T>) -> Option<&mut Node<T>> {
+        self.nodes.get_mut(usize::from(index))
+    }
+}
+
+/// Tree operations
+impl<T> Tree<T> {
+    pub fn new() -> Self {
+        Self { nodes: Default::default() }
+    }
+
+    /// Creates a new root for the tree.
+    ///
+    /// If the tree already has a root, the value will be returned.
+    pub fn root(&mut self, value: T) -> Result<Ref<T>, T> {
+        if self.is_empty() {
+            // Create an index for the new node
+            let node = Ref::new_unchecked(self.nodes.len());
+            // add child to tree
+            self.nodes.push(Node::from(value));
+            Ok(node)
+        } else {
+            Err(value)
+        }
+    }
+
+    pub fn get_root(&mut self) -> Option<Ref<T>> {
+        match self.nodes.is_empty() {
+            true => None,
+            false => Some(Ref::new_unchecked(0)),
+        }
+    }
+
+    /// Insert a value into the tree as a child of the parent node
+    ///
+    /// # Panics
+    /// May panic if the node [Ref] is from a different tree
+    pub fn insert(&mut self, value: T, parent: Ref<T>) -> Ref<T> {
+        let child = Ref::new_unchecked(self.nodes.len());
+        // add child to tree before parent
+        self.nodes.push(Node::with_parent(value, parent));
+        // add child to parent
+        self[parent].children.push(child);
+
+        child
+    }
+
+    /// Gets the depth of a node
+    ///
+    /// # Panics
+    /// May panic if the node [Ref] is from a different tree
+    pub fn depth(&self, node: Ref<T>) -> usize {
+        match self[node].parent {
+            Some(node) => self.depth(node) + 1,
+            None => 0,
+        }
+    }
+
+    /// Gets the number of branches in the tree
+    pub fn branches(&self) -> usize {
+        self.nodes.iter().fold(0, |edges, node| edges + node.len())
+    }
+}
+
+/// Standard data structure functions
+impl<T> Tree<T> {
+    pub fn len(&self) -> usize {
+        self.nodes.len()
+    }
+    pub fn is_empty(&self) -> bool {
+        self.nodes.is_empty()
+    }
+}
+
+impl<T> Index<Ref<T>> for Tree<T> {
+    type Output = Node<T>;
+    fn index(&self, index: Ref<T>) -> &Self::Output {
+        self.get_node(index).expect("Ref should be inside Tree")
+    }
+}
+impl<T> IndexMut<Ref<T>> for Tree<T> {
+    fn index_mut(&mut self, index: Ref<T>) -> &mut Self::Output {
+        self.get_node_mut(index).expect("Ref should be inside Tree")
+    }
+}
+
+/// A node in a [Tree]
+#[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub struct Node<T> {
+    value: T,
+    /// The parent
+    parent: Option<Ref<T>>,
+    /// The children
+    children: Vec<Ref<T>>,
+}
+
+impl<T> Node<T> {
+    pub const fn new(value: T) -> Self {
+        Self { value, parent: None, children: vec![] }
+    }
+    pub const fn with_parent(value: T, parent: Ref<T>) -> Self {
+        Self { value, parent: Some(parent), children: vec![] }
+    }
+
+    pub fn get(&self) -> &T {
+        self.as_ref()
+    }
+    pub fn get_mut(&mut self) -> &mut T {
+        self.as_mut()
+    }
+    pub fn swap(&mut self, value: T) -> T {
+        std::mem::replace(&mut self.value, value)
+    }
+
+    pub fn parent(&self) -> Option<Ref<T>> {
+        self.parent
+    }
+    pub fn children(&self) -> &[Ref<T>] {
+        &self.children
+    }
+
+    pub fn len(&self) -> usize {
+        self.children.len()
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.children.is_empty()
+    }
+}
+
+impl<T> AsRef<T> for Node<T> {
+    fn as_ref(&self) -> &T {
+        &self.value
+    }
+}
+impl<T> AsMut<T> for Node<T> {
+    fn as_mut(&mut self) -> &mut T {
+        &mut self.value
+    }
+}
+
+impl<T> From<T> for Node<T> {
+    #[inline]
+    fn from(value: T) -> Self {
+        Self::new(value)
+    }
+}
+
+#[cfg(test)]
+mod test {
+    #[allow(unused)]
+    use super::*;
+
+    #[test]
+    fn add_children() {
+        let mut tree = Tree::new();
+        let root = tree.root(0).unwrap();
+        let one = tree.insert(1, root);
+        let two = tree.insert(2, root);
+        assert_eq!([one, two].as_slice(), tree[root].children());
+    }
+    #[test]
+    fn nest_children() {
+        let mut tree = Tree::new();
+        let root = tree.root(0).unwrap();
+        let one = tree.insert(1, root);
+        let two = tree.insert(2, one);
+        assert_eq!(&[one], tree[root].children());
+        assert_eq!(&[two], tree[one].children());
+        assert_eq!(tree[two].children(), &[]);
+    }
+
+    #[test]
+    fn compares_equal() {}
+}

cl-structures/src/tree/tree_ref.rs

@@ -0,0 +1,70 @@
+//! An element in a [Tree](super::Tree)
+///
+/// Contains a niche, and as such, [`Option<TreeRef<T>>`] is free :D
+use std::{marker::PhantomData, num::NonZeroUsize};
+
+/// An element of in a [Tree](super::Tree).
+//? The index of the node is stored as a [NonZeroUsize] for space savings
+//? Making Refs T-specific helps the user keep track of which Refs belong to which trees.
+//? This isn't bulletproof, of course, but it'll keep Ref<Foo> from being used on Tree<Bar>
+pub struct Ref<T: ?Sized>(NonZeroUsize, PhantomData<T>);
+
+impl<T: ?Sized> Ref<T> {
+    /// Constructs a new [Ref] with the given index
+    pub fn new_unchecked(index: usize) -> Self {
+        // Safety: index cannot be zero because we use saturating addition on unsigned type.
+        Self(
+            unsafe { NonZeroUsize::new_unchecked(index.saturating_add(1)) },
+            PhantomData,
+        )
+    }
+}
+
+impl<T: ?Sized> From<Ref<T>> for usize {
+    fn from(value: Ref<T>) -> Self {
+        usize::from(value.0) - 1
+    }
+}
+
+/* --- implementations of derivable traits, because we don't need bounds here --- */
+
+impl<T: ?Sized> std::fmt::Debug for Ref<T> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_tuple("TreeRef").field(&self.0).finish()
+    }
+}
+
+impl<T: ?Sized> std::hash::Hash for Ref<T> {
+    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+        self.0.hash(state);
+        self.1.hash(state);
+    }
+}
+
+impl<T: ?Sized> PartialEq for Ref<T> {
+    fn eq(&self, other: &Self) -> bool {
+        self.0 == other.0 && self.1 == other.1
+    }
+}
+
+impl<T: ?Sized> Eq for Ref<T> {}
+
+impl<T: ?Sized> PartialOrd for Ref<T> {
+    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+impl<T: ?Sized> Ord for Ref<T> {
+    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
+        self.0.cmp(&other.0)
+    }
+}
+
+impl<T: ?Sized> Clone for Ref<T> {
+    fn clone(&self) -> Self {
+        *self
+    }
+}
+
+impl<T: ?Sized> Copy for Ref<T> {}

cl-token/Cargo.toml

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

cl-token/src/lib.rs

@@ -0,0 +1,13 @@
+//! # Token
+//!
+//! Stores a component of a file as a [TokenKind], some [TokenData], and a line and column number
+#![warn(clippy::all)]
+#![feature(decl_macro)]
+
+pub mod token;
+pub mod token_data;
+pub mod token_type;
+
+pub use token::Token;
+pub use token_data::TokenData;
+pub use token_type::{Punct, TokenKind};

cl-token/src/token.rs

@@ -0,0 +1,42 @@
+//! A [Token] contains a single unit of lexical information, and an optional bit of [TokenData]
+use super::{TokenData, TokenKind};
+
+/// Contains a single unit of lexical information,
+/// and an optional bit of [TokenData]
+#[derive(Clone, Debug, PartialEq)]
+pub struct Token {
+    pub ty: TokenKind,
+    pub data: TokenData,
+    pub line: u32,
+    pub col: u32,
+}
+impl Token {
+    /// Creates a new [Token] out of a [TokenKind], [TokenData], line, and column.
+    pub fn new(ty: TokenKind, data: impl Into<TokenData>, line: u32, col: u32) -> Self {
+        Self { ty, data: data.into(), line, col }
+    }
+    /// Casts this token to a new [TokenKind]
+    pub fn cast(self, ty: TokenKind) -> Self {
+        Self { ty, ..self }
+    }
+    /// Returns the [TokenKind] of this token
+    pub fn ty(&self) -> TokenKind {
+        self.ty
+    }
+    /// Returns a reference to this token's [TokenData]
+    pub fn data(&self) -> &TokenData {
+        &self.data
+    }
+    /// Converts this token into its inner [TokenData]
+    pub fn into_data(self) -> TokenData {
+        self.data
+    }
+    /// Returns the line where this token originated
+    pub fn line(&self) -> u32 {
+        self.line
+    }
+    /// Returns the column where this token originated
+    pub fn col(&self) -> u32 {
+        self.col
+    }
+}

cl-token/src/token_data.rs

@@ -1,11 +1,9 @@
 //! Additional data stored within a [Token](super::Token),
-//! external to its [Type](super::token_type::Type)
+//! external to its [TokenKind](super::token_type::TokenKind)
 /// Additional data stored within a [Token](super::Token),
-/// external to its [Type](super::token_type::Type)
+/// external to its [TokenKind](super::token_type::TokenKind)
 #[derive(Clone, Debug, PartialEq)]
-pub enum Data {
-    /// [Token](super::Token) contains an [identifier](str)
-    Identifier(Box<str>),
+pub enum TokenData {
     /// [Token](super::Token) contains a [String]
     String(String),
     /// [Token](super::Token) contains a [character](char)
@@ -18,7 +16,6 @@ pub enum Data {
     None,
 }
 from! {
-    value: &str => Self::Identifier(value.into()),
     value: String => Self::String(value),
     value: u128 => Self::Integer(value),
     value: f64 => Self::Float(value),
@@ -27,19 +24,18 @@ from! {
 }
 /// Implements [From] for an enum
 macro from($($value:ident: $src:ty => $dst:expr),*$(,)?) {
-    $(impl From<$src> for Data {
+    $(impl From<$src> for TokenData {
         fn from($value: $src) -> Self { $dst }
     })*
 }
-impl std::fmt::Display for Data {
+impl std::fmt::Display for TokenData {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
-            Data::Identifier(v) => v.fmt(f),
-            Data::String(v) => write!(f, "\"{v}\""),
-            Data::Character(v) => write!(f, "'{v}'"),
-            Data::Integer(v) => v.fmt(f),
-            Data::Float(v) => v.fmt(f),
-            Data::None => "None".fmt(f),
+            TokenData::String(v) => write!(f, "\"{v}\""),
+            TokenData::Character(v) => write!(f, "'{v}'"),
+            TokenData::Integer(v) => v.fmt(f),
+            TokenData::Float(v) => v.fmt(f),
+            TokenData::None => "None".fmt(f),
         }
     }
 }

cl-token/src/token_type.rs

@@ -0,0 +1,237 @@
+//! Stores a [Token's](super::Token) lexical information
+use std::{fmt::Display, str::FromStr};
+
+/// Stores a [Token's](super::Token) lexical information
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+pub enum TokenKind {
+    /// Invalid sequence
+    Invalid,
+    /// Any kind of comment
+    Comment,
+    /// Any tokenizable literal (See [TokenData](super::TokenData))
+    Literal,
+    /// A non-keyword identifier
+    Identifier,
+    // A keyword
+    Break,
+    Cl,
+    Const,
+    Continue,
+    Else,
+    Enum,
+    False,
+    For,
+    Fn,
+    If,
+    Impl,
+    In,
+    Let,
+    Mod,
+    Mut,
+    Pub,
+    Return,
+    SelfKw,
+    SelfTy,
+    Static,
+    Struct,
+    Super,
+    True,
+    Type,
+    While,
+    /// Delimiter or punctuation
+    Punct(Punct),
+}
+
+/// An operator character (delimiter, punctuation)
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+pub enum Punct {
+    LCurly,     // {
+    RCurly,     // }
+    LBrack,     // [
+    RBrack,     // ]
+    LParen,     // (
+    RParen,     // )
+    Amp,        // &
+    AmpAmp,     // &&
+    AmpEq,      // &=
+    Arrow,      // ->
+    At,         // @
+    Backslash,  // \
+    Bang,       // !
+    BangBang,   // !!
+    BangEq,     // !=
+    Bar,        // |
+    BarBar,     // ||
+    BarEq,      // |=
+    Colon,      // :
+    ColonColon, // ::
+    Comma,      // ,
+    Dot,        // .
+    DotDot,     // ..
+    DotDotEq,   // ..=
+    Eq,         // =
+    EqEq,       // ==
+    FatArrow,   // =>
+    Grave,      // `
+    Gt,         // >
+    GtEq,       // >=
+    GtGt,       // >>
+    GtGtEq,     // >>=
+    Hash,       // #
+    HashBang,   // #!
+    Lt,         // <
+    LtEq,       // <=
+    LtLt,       // <<
+    LtLtEq,     // <<=
+    Minus,      // -
+    MinusEq,    // -=
+    Plus,       // +
+    PlusEq,     // +=
+    Question,   // ?
+    Rem,        // %
+    RemEq,      // %=
+    Semi,       // ;
+    Slash,      // /
+    SlashEq,    // /=
+    Star,       // *
+    StarEq,     // *=
+    Tilde,      // ~
+    Xor,        // ^
+    XorEq,      // ^=
+    XorXor,     // ^^
+}
+
+impl Display for TokenKind {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            TokenKind::Invalid => "invalid".fmt(f),
+            TokenKind::Comment => "comment".fmt(f),
+            TokenKind::Literal => "literal".fmt(f),
+            TokenKind::Identifier => "identifier".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::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::While => "while".fmt(f),
+
+            TokenKind::Punct(op) => op.fmt(f),
+        }
+    }
+}
+impl FromStr for TokenKind {
+    /// [FromStr] can only fail when an identifier isn't a keyword
+    type Err = ();
+    /// Parses a string s to return a Keyword
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        Ok(match s {
+            "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,
+            "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,
+            "while" => 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),
+        }
+    }
+}

cl-typeck/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "cl-typeck"
+repository.workspace = true
+version.workspace = true
+authors.workspace = true
+edition.workspace = true
+license.workspace = true
+publish.workspace = true
+
+[dependencies]
+cl-ast = { path = "../cl-ast" }
+cl-structures = { path = "../cl-structures" }

cl-typeck/src/lib.rs

@@ -0,0 +1,909 @@
+//! # The Conlang Type Checker
+//!
+//! As a statically typed language, Conlang requires a robust type checker to enforce correctness.
+#![feature(debug_closure_helpers)]
+#![warn(clippy::all)]
+
+/*
+
+The type checker keeps track of a *global intern pool* for Types and Values
+References to the intern pool are held by ID, and items cannot be freed from the pool EVER.
+
+Items are inserted into their respective pools,
+
+
+*/
+
+pub mod key {
+    use cl_structures::intern_pool::*;
+
+    // define the index types
+    make_intern_key! {
+        /// Uniquely represents a [Def][1] in the [Def][1] [Pool]
+        ///
+        /// [1]: crate::definition::Def
+        DefID,
+    }
+}
+
+pub mod definition {
+    use crate::{key::DefID, module::Module, type_kind::TypeKind, value_kind::ValueKind};
+    use cl_ast::{format::FmtPretty, Item, Meta, Visibility};
+    use std::fmt::Write;
+
+    #[derive(Clone, PartialEq, Eq)]
+    pub struct Def {
+        pub name: String,
+        pub vis: Visibility,
+        pub meta: Vec<Meta>,
+        pub kind: DefKind,
+        pub source: Option<Item>,
+        pub module: Module,
+    }
+
+    impl Default for Def {
+        fn default() -> Self {
+            Self {
+                name: Default::default(),
+                vis: Default::default(),
+                meta: Default::default(),
+                kind: DefKind::Type(TypeKind::Module),
+                source: Default::default(),
+                module: Default::default(),
+            }
+        }
+    }
+
+    impl Def {
+        pub fn new_module(
+            name: String,
+            vis: Visibility,
+            meta: Vec<Meta>,
+            parent: Option<DefID>,
+        ) -> Self {
+            Self {
+                name,
+                vis,
+                meta,
+                kind: DefKind::Type(TypeKind::Module),
+                source: None,
+                module: Module { parent, ..Default::default() },
+            }
+        }
+    }
+
+    impl std::fmt::Debug for Def {
+        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+            let Self { name, vis, meta, kind, source, module } = self;
+            f.debug_struct("Def")
+                .field("name", &name)
+                .field("vis", &vis)
+                .field_with("meta", |f| write!(f, "{meta:?}"))
+                .field("kind", &kind)
+                .field_with("source", |f| match source {
+                    Some(item) => write!(f.pretty(), "{{\n{item}\n}}"),
+                    None => todo!(),
+                })
+                .field("module", &module)
+                .finish()
+        }
+    }
+
+    #[derive(Clone, Debug, PartialEq, Eq)]
+    pub enum DefKind {
+        /// A type, such as a ``
+        Type(TypeKind),
+        /// A value, such as a `const`, `static`, or `fn`
+        Value(ValueKind),
+    }
+
+    impl DefKind {
+        pub fn is_type(&self) -> bool {
+            matches!(self, Self::Type(_))
+        }
+        pub fn ty(&self) -> Option<&TypeKind> {
+            match self {
+                DefKind::Type(t) => Some(t),
+                _ => None,
+            }
+        }
+        pub fn is_value(&self) -> bool {
+            matches!(self, Self::Value(_))
+        }
+        pub fn value(&self) -> Option<&ValueKind> {
+            match self {
+                DefKind::Value(v) => Some(v),
+                _ => None,
+            }
+        }
+    }
+}
+
+pub mod type_kind {
+    //! A [TypeKind] represents an item in the Type Namespace
+    //! (a component of a [Project](crate::project::Project)).
+
+    use cl_ast::Visibility;
+    use std::{fmt::Debug, str::FromStr};
+
+    use crate::key::DefID;
+
+    /// The kind of a type
+    #[derive(Clone, Debug, PartialEq, Eq)]
+    pub enum TypeKind {
+        /// A type which has not yet been resolved
+        Undecided,
+        /// An alias for an already-defined type
+        Alias(Option<DefID>),
+        /// A primitive type, built-in to the compiler
+        Intrinsic(Intrinsic),
+        /// A user-defined abstract data type
+        Adt(Adt),
+        /// A reference to an already-defined type: &T
+        Ref(DefID),
+        /// A contiguous view of dynamically sized memory
+        Slice(DefID),
+        /// A function pointer which accepts multiple inputs and produces an output
+        FnPtr { args: Vec<DefID>, rety: DefID },
+        /// The unit type
+        Empty,
+        /// The never type
+        Never,
+        /// The Self type
+        SelfTy,
+        /// An untyped module
+        Module,
+    }
+
+    /// A user-defined Abstract Data Type
+    #[derive(Clone, Debug, PartialEq, Eq)]
+    pub enum Adt {
+        /// A union-like enum type
+        Enum(Vec<(String, DefID)>),
+        CLikeEnum(Vec<(String, u128)>),
+        /// An enum with no fields, which can never be constructed
+        FieldlessEnum,
+
+        /// A structural product type with named members
+        Struct(Vec<(String, 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<(String, 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)]
+    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,
+        /// 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 boolean (`true` or `false`): `#[intrinsic = "bool"]`
+        Bool,
+    }
+
+    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,
+                "u8" => Intrinsic::U8,
+                "u16" => Intrinsic::U16,
+                "u32" => Intrinsic::U32,
+                "u64" => Intrinsic::U64,
+                "bool" => Intrinsic::Bool,
+                _ => Err(())?,
+            })
+        }
+    }
+
+    #[derive(Clone, Debug, PartialEq, Eq)]
+    pub enum Float {
+        F32 = 0x20,
+        F64,
+    }
+}
+
+pub mod value_kind {
+    //! A [ValueKind] represents an item in the Value Namespace
+    //! (a component of a [Project](crate::project::Project)).
+
+    use crate::typeref::TypeRef;
+    use cl_ast::Block;
+
+    #[derive(Clone, Debug, PartialEq, Eq)]
+    pub enum ValueKind {
+        Undecided,
+        Const(TypeRef),
+        Static(TypeRef),
+        Fn {
+            // TODO: Store the variable bindings here!
+            args: Vec<TypeRef>,
+            rety: TypeRef,
+            body: Block,
+        },
+    }
+}
+
+pub mod module {
+    //! A [Module] is a node in the Module Tree (a component of a
+    //! [Project](crate::project::Project))
+    use crate::key::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<String, DefID>,
+        pub values: HashMap<String, DefID>,
+    }
+
+    impl Module {
+        pub fn new(parent: DefID) -> Self {
+            Self { parent: Some(parent), ..Default::default() }
+        }
+    }
+}
+
+pub mod path {
+    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 is_empty(&self) -> bool {
+            self.parts.is_empty()
+        }
+        pub fn len(&self) -> usize {
+            self.parts.len()
+        }
+        pub fn front(&self) -> Option<&PathPart> {
+            self.parts.first()
+        }
+    }
+
+    impl<'p> From<&'p AstPath> for Path<'p> {
+        fn from(value: &'p AstPath) -> Self {
+            Self::new(value)
+        }
+    }
+    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(())
+        }
+    }
+}
+
+pub mod project {
+    use crate::{
+        definition::{Def, DefKind},
+        key::DefID,
+        path::Path,
+        type_kind::TypeKind,
+    };
+    use cl_ast::{Identifier, PathPart, Visibility};
+    use cl_structures::intern_pool::Pool;
+    use std::ops::{Index, IndexMut};
+
+    #[derive(Clone, Debug, PartialEq, Eq)]
+    pub struct Project {
+        pub pool: Pool<Def, DefID>,
+        pub module_root: DefID,
+    }
+
+    impl Project {
+        pub fn new() -> Self {
+            Self::default()
+        }
+    }
+    impl Default for Project {
+        fn default() -> Self {
+            let mut pool = Pool::default();
+            let module_root = pool.insert(Def::default());
+            // Insert the Never(!) type
+            let never = pool.insert(Def {
+                name: String::from("!"),
+                vis: Visibility::Public,
+                kind: DefKind::Type(TypeKind::Never),
+                ..Default::default()
+            });
+            pool[module_root]
+                .module
+                .types
+                .insert(String::from("!"), never);
+            Self { pool, module_root }
+        }
+    }
+
+    impl Project {
+        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,
+            }
+        }
+        /// Resolves a path within a module tree, finding the innermost module.
+        /// Returns the remaining path parts.
+        pub fn get_type<'a>(&self, path: Path<'a>, within: DefID) -> Option<(DefID, Path<'a>)> {
+            // TODO: Cache module lookups
+            if path.absolute {
+                self.get_type(path.relative(), self.root_of(within))
+            } else if let Some(front) = path.front() {
+                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::Ident(Identifier(name)) => match module.types.get(name) {
+                        Some(&submodule) => self.get_type(path.pop_front()?, submodule),
+                        None => Some((within, path)),
+                    },
+                }
+            } else {
+                Some((within, path))
+            }
+        }
+
+        pub fn get_value<'a>(&self, path: Path<'a>, within: DefID) -> Option<(DefID, Path<'a>)> {
+            match path.front()? {
+                PathPart::Ident(Identifier(name)) => Some((
+                    self[within].module.values.get(name).copied()?,
+                    path.pop_front()?,
+                )),
+                _ => None,
+            }
+        }
+
+        #[rustfmt::skip]
+        pub fn insert_type(&mut self, name: String, value: Def, parent: DefID) -> Option<DefID> {
+            let id = self.pool.insert(value);
+            self[parent].module.types.insert(name, id)
+        }
+        #[rustfmt::skip]
+        pub fn insert_value(&mut self, name: String, value: Def, parent: DefID) -> Option<DefID> {
+            let id = self.pool.insert(value);
+            self[parent].module.values.insert(name, id)
+        }
+    }
+
+    /// Implements [Index] and [IndexMut] for [Project]: `self.table[ID] -> Definition`
+    macro_rules! impl_index {
+        ($(self.$table:ident[$idx:ty] -> $out:ty),*$(,)?) => {$(
+            impl Index<$idx> for Project {
+                type Output = $out;
+                fn index(&self, index: $idx) -> &Self::Output {
+                    &self.$table[index]
+                }
+            }
+            impl IndexMut<$idx> for Project {
+                fn index_mut(&mut self, index: $idx) -> &mut Self::Output {
+                    &mut self.$table[index]
+                }
+            }
+        )*};
+    }
+    impl_index! {
+        self.pool[DefID] -> Def,
+        // self.types[TypeID] -> TypeDef,
+        // self.values[ValueID] -> ValueDef,
+    }
+}
+
+pub mod name_collector {
+    //! Performs step 1 of type checking: Collecting all the names of things into [Module] units
+
+    use crate::{
+        definition::{Def, DefKind},
+        key,
+        project::Project,
+        type_kind::{Adt, TypeKind},
+        value_kind::ValueKind,
+    };
+    use cl_ast::*;
+    use std::ops::{Deref, DerefMut};
+
+    /// Collects types for future use
+    #[derive(Debug, PartialEq, Eq)]
+    pub struct NameCollector<'prj> {
+        /// A stack of the current modules
+        pub mod_stack: Vec<key::DefID>,
+        /// The [Project], the type checker and resolver's central data store
+        pub project: &'prj mut Project,
+    }
+
+    impl<'prj> NameCollector<'prj> {
+        pub fn new(project: &'prj mut Project) -> Self {
+            // create a root module
+            Self { mod_stack: vec![project.module_root], project }
+        }
+
+        /// Gets the currently traversed parent module
+        pub fn parent(&self) -> Option<key::DefID> {
+            self.mod_stack.last().copied()
+        }
+    }
+
+    impl Deref for NameCollector<'_> {
+        type Target = Project;
+        fn deref(&self) -> &Self::Target {
+            self.project
+        }
+    }
+    impl DerefMut for NameCollector<'_> {
+        fn deref_mut(&mut self) -> &mut Self::Target {
+            self.project
+        }
+    }
+
+    impl NameCollector<'_> {
+        pub fn file(&mut self, f: &File) -> Result<(), &'static str> {
+            let parent = self.parent().ok_or("No parent to add item to")?;
+
+            for item in &f.items {
+                let def = match &item.kind {
+                    // modules
+                    // types
+                    ItemKind::Module(_) => {
+                        self.module(item)?;
+                        continue;
+                    }
+                    ItemKind::Enum(_) => Some(self.ty_enum(item)?),
+                    ItemKind::Alias(_) => Some(self.ty_alias(item)?),
+                    ItemKind::Struct(_) => Some(self.ty_struct(item)?),
+                    // values processed by the value collector
+                    ItemKind::Const(_) => Some(self.val_const(item)?),
+                    ItemKind::Static(_) => Some(self.val_static(item)?),
+                    ItemKind::Function(_) => Some(self.val_function(item)?),
+                    ItemKind::Impl(_) => None,
+                };
+                let Some(def) = def else { continue };
+                match def.kind {
+                    DefKind::Type(_) => {
+                        if let Some(v) = self.insert_type(def.name.clone(), def, parent) {
+                            panic!("Redefinition of type {} ({v:?})!", self[v].name)
+                        }
+                    }
+                    DefKind::Value(_) => {
+                        if let Some(v) = self.insert_value(def.name.clone(), def, parent) {
+                            panic!("Redefinition of value {} ({v:?})!", self[v].name)
+                        }
+                    }
+                }
+            }
+            Ok(())
+        }
+
+        /// Collects a [Module]
+        pub fn module(&mut self, m: &Item) -> Result<(), &'static str> {
+            let Item { kind: ItemKind::Module(Module { name, kind }), vis, attrs, .. } = m else {
+                Err("module called on Item which was not an ItemKind::Module")?
+            };
+            let ModuleKind::Inline(kind) = kind else {
+                Err("Out-of-line modules not yet supported")?
+            };
+            let parent = self.parent().ok_or("No parent to add module to")?;
+
+            let module = self.pool.insert(Def::new_module(
+                name.0.clone(),
+                *vis,
+                attrs.meta.clone(),
+                Some(parent),
+            ));
+
+            self[parent]
+                .module
+                .types
+                .insert(name.0.clone(), module)
+                .is_some()
+                .then(|| panic!("Error: redefinition of module {name}"));
+
+            self.mod_stack.push(module);
+            let out = self.file(kind);
+            self.mod_stack.pop();
+
+            out
+        }
+    }
+    /// Type collection
+    impl NameCollector<'_> {
+        /// Collects an [Item] of type [ItemKind::Enum]
+        pub fn ty_enum(&mut self, item: &Item) -> Result<Def, &'static str> {
+            let Item { kind: ItemKind::Enum(Enum { name, kind }), vis, attrs, .. } = item else {
+                Err("Enum called on item which was not ItemKind::Enum")?
+            };
+            let kind = match kind {
+                EnumKind::NoVariants => DefKind::Type(TypeKind::Adt(Adt::FieldlessEnum)),
+                EnumKind::Variants(_) => DefKind::Type(TypeKind::Undecided),
+            };
+
+            Ok(Def {
+                name: name.0.clone(),
+                vis: *vis,
+                meta: attrs.meta.clone(),
+                kind,
+                source: Some(item.clone()),
+                module: Default::default(),
+            })
+        }
+
+        /// Collects an [Item] of type [ItemKind::Alias]
+        pub fn ty_alias(&mut self, item: &Item) -> Result<Def, &'static str> {
+            let Item { kind: ItemKind::Alias(Alias { to: name, from }), vis, attrs, .. } = item
+            else {
+                Err("Alias called on Item which was not ItemKind::Alias")?
+            };
+
+            let mut kind = match from {
+                Some(_) => DefKind::Type(TypeKind::Undecided),
+                None => DefKind::Type(TypeKind::Alias(None)),
+            };
+
+            for meta in &attrs.meta {
+                let Meta { name: meta_name, kind: meta_kind } = meta;
+                match (meta_name.0.as_str(), meta_kind) {
+                    ("intrinsic", MetaKind::Equals(Literal::String(intrinsic))) => {
+                        kind = DefKind::Type(TypeKind::Intrinsic(
+                            intrinsic.parse().map_err(|_| "unknown intrinsic type")?,
+                        ));
+                    }
+                    ("intrinsic", MetaKind::Plain) => {
+                        kind = DefKind::Type(TypeKind::Intrinsic(
+                            name.0.parse().map_err(|_| "Unknown intrinsic type")?,
+                        ))
+                    }
+                    _ => {}
+                }
+            }
+
+            Ok(Def {
+                name: name.0.clone(),
+                vis: *vis,
+                meta: attrs.meta.clone(),
+                kind,
+                source: Some(item.clone()),
+                module: Default::default(),
+            })
+        }
+
+        /// Collects an [Item] of type [ItemKind::Struct]
+        pub fn ty_struct(&mut self, item: &Item) -> Result<Def, &'static str> {
+            let Item { kind: ItemKind::Struct(Struct { name, kind }), vis, attrs, .. } = item
+            else {
+                Err("Struct called on item which was not ItemKind::Struct")?
+            };
+            let kind = match kind {
+                StructKind::Empty => DefKind::Type(TypeKind::Adt(Adt::UnitStruct)),
+                StructKind::Tuple(_) => DefKind::Type(TypeKind::Undecided),
+                StructKind::Struct(_) => DefKind::Type(TypeKind::Undecided),
+            };
+
+            Ok(Def {
+                name: name.0.clone(),
+                vis: *vis,
+                meta: attrs.meta.clone(),
+                kind,
+                source: Some(item.clone()),
+                module: Default::default(),
+            })
+        }
+    }
+    /// Value collection
+    impl NameCollector<'_> {
+        pub fn val_const(&mut self, item: &Item) -> Result<Def, &'static str> {
+            let Item { kind: ItemKind::Const(Const { name, .. }), vis, attrs, .. } = item else {
+                Err("Const called on Item which was not ItemKind::Const")?
+            };
+
+            Ok(Def {
+                name: name.0.clone(),
+                vis: *vis,
+                meta: attrs.meta.clone(),
+                kind: DefKind::Value(ValueKind::Undecided),
+                source: Some(item.clone()),
+                module: Default::default(),
+            })
+        }
+
+        pub fn val_static(&mut self, item: &Item) -> Result<Def, &'static str> {
+            let Item { kind: ItemKind::Static(Static { name, .. }), vis, attrs, .. } = item else {
+                Err("Static called on Item which was not ItemKind::Static")?
+            };
+            Ok(Def {
+                name: name.0.clone(),
+                vis: *vis,
+                meta: attrs.meta.clone(),
+                kind: DefKind::Type(TypeKind::Undecided),
+                source: Some(item.clone()),
+                module: Default::default(),
+            })
+        }
+
+        pub fn val_function(&mut self, item: &Item) -> Result<Def, &'static str> {
+            // TODO: treat function bodies like modules with internal items
+            let Item { kind: ItemKind::Function(Function { name, .. }), vis, attrs, .. } = item
+            else {
+                Err("val_function called on Item which was not ItemKind::Function")?
+            };
+            Ok(Def {
+                name: name.0.clone(),
+                vis: *vis,
+                meta: attrs.meta.clone(),
+                kind: DefKind::Value(ValueKind::Undecided),
+                source: Some(item.clone()),
+                module: Default::default(),
+            })
+        }
+    }
+}
+
+pub mod type_resolver {
+    //! Performs step 2 of type checking: Evaluating type definitions
+    #![allow(unused)]
+    use std::ops::{Deref, DerefMut};
+
+    use cl_ast::*;
+
+    use crate::{definition::Def, key::DefID, project::Project};
+
+    pub struct TypeResolver<'prj> {
+        pub project: &'prj mut Project,
+    }
+
+    impl Deref for TypeResolver<'_> {
+        type Target = Project;
+        fn deref(&self) -> &Self::Target {
+            self.project
+        }
+    }
+    impl DerefMut for TypeResolver<'_> {
+        fn deref_mut(&mut self) -> &mut Self::Target {
+            self.project
+        }
+    }
+
+    impl TypeResolver<'_> {
+        pub fn resolve(&mut self) -> Result<bool, &str> {
+            #![allow(unused)]
+            for typedef in self.pool.iter_mut().filter(|v| v.kind.is_type()) {
+                let Def { name, vis, meta: attr, kind, source: Some(ref definition), module: _ } =
+                    typedef
+                else {
+                    continue;
+                };
+                match &definition.kind {
+                    ItemKind::Alias(Alias { to: _, from: Some(from) }) => match &from.kind {
+                        TyKind::Never => todo!(),
+                        TyKind::Empty => todo!(),
+                        TyKind::SelfTy => todo!(),
+                        TyKind::Path(_) => todo!(),
+                        TyKind::Tuple(_) => todo!(),
+                        TyKind::Ref(_) => todo!(),
+                        TyKind::Fn(_) => todo!(),
+                    },
+                    ItemKind::Alias(_) => {}
+                    ItemKind::Const(_) => todo!(),
+                    ItemKind::Static(_) => todo!(),
+                    ItemKind::Module(_) => todo!(),
+                    ItemKind::Function(_) => {}
+                    ItemKind::Struct(_) => {}
+                    ItemKind::Enum(_) => {}
+                    ItemKind::Impl(_) => {}
+                }
+            }
+            Ok(true)
+        }
+
+        pub fn get_type(&self, kind: &TyKind) -> Option<DefID> {
+            match kind {
+                TyKind::Never => todo!(),
+                TyKind::Empty => todo!(),
+                TyKind::SelfTy => todo!(),
+                TyKind::Path(_) => todo!(),
+                TyKind::Tuple(_) => todo!(),
+                TyKind::Ref(_) => todo!(),
+                TyKind::Fn(_) => todo!(),
+            }
+            None
+        }
+    }
+}
+
+pub mod typeref {
+    //! Stores type and reference info
+
+    use crate::key::DefID;
+
+    /// The Type struct represents all valid types, and can be trivially equality-compared
+    #[derive(Clone, Debug, PartialEq, Eq)]
+    pub struct TypeRef {
+        /// You can only have a pointer chain 65535 pointers long.
+        ref_depth: u16,
+        /// Types can be [Generic](RefKind::Generic) or [Concrete](RefKind::Concrete)
+        kind: RefKind,
+    }
+
+    /// Types can be [Generic](RefKind::Generic) or [Concrete](RefKind::Concrete)
+    #[derive(Clone, Debug, PartialEq, Eq)]
+    pub enum RefKind {
+        /// A Concrete type has an associated [Def](super::definition::Def)
+        Concrete(DefID),
+        /// A Generic type is a *locally unique* comparable value,
+        /// valid only until the end of its typing context.
+        /// This is usually the surrounding function.
+        Generic(usize),
+    }
+}
+
+/*
+/// What is an inference rule?
+/// An inference rule is a specification with a set of predicates and a judgement
+
+/// Let's give every type an ID
+struct TypeID(usize);
+
+/// Let's give every type some data:
+
+struct TypeDef<'def> {
+    name: String,
+    definition: &'def Item,
+}
+
+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>> {
+
+}
+
+*/
+
+pub mod rule {
+    use crate::{key::DefID, typeref::TypeRef};
+
+    pub struct Rule {
+        /// What is this Rule for?
+        pub operation: (),
+        /// What inputs does it take?
+        pub inputs: Vec<TypeRef>,
+        /// What output does it produce?
+        pub output: TypeRef,
+        /// Where did this rule come from?
+        pub through: Origin,
+    }
+
+    // TODO: Genericize
+    pub enum Operation {
+        Mul,
+        Div,
+        Rem,
+        Add,
+        Sub,
+
+        Deref,
+        Neg,
+        Not,
+        At,
+        Tilde,
+
+        Index,
+
+        If,
+        While,
+        For,
+    }
+
+    pub enum Origin {
+        /// This rule is built into the compiler
+        Intrinsic,
+        /// This rule is derived from an implementation on a type
+        Extrinsic(DefID),
+    }
+}
+
+pub mod typeck {
+    #![allow(unused)]
+    use cl_ast::*;
+
+    pub struct Context {
+        rules: (),
+    }
+
+    trait TypeCheck {}
+}
+
+//

grammar.ebnf

@@ -1,38 +1,38 @@
 (* Conlang Expression Grammar *)
-Start       = File ;
+Start       = File EOI ;
 
 Mutability  = "mut"? ;
 Visibility  = "pub"? ;
 
 
-File        = Item* EOI ;
+File        = Item* ;
 
 
-Attrs       = ('#' '[' (Meta ',') Meta? ']')* ;
+Attrs       = ('#' '[' (Meta ',')* Meta? ']')* ;
 Meta        = Identifier ('=' Literal | '(' (Literal ',')* Literal? ')')? ;
 
 
-Item        = Attrs* Visibility ItemKind ;
+Item        = Attrs Visibility ItemKind ;
 ItemKind    = Const    | Static | Module 
             | Function | Struct | Enum 
             | Alias    | Impl ;
 
 
 (* item *)
-Const       = "const" Identifier ':' Type = Expr ';' ;
+Const       = "const" Identifier ':' Ty '=' Expr ';' ;
 
-Static      = "static" Mutability Identifier ':' Type = Expr ';' ;
+Static      = "static" Mutability Identifier ':' Ty '=' Expr ';' ;
 
 Module      = "mod" Identifier ModuleKind ;
 ModuleKind  = '{' Item* '}' | ';' ;
 
-Function    = "fn" Identifier '(' (Param ',')* Param? ')' ('->' Type)? Block? ;
-Param       = Mutability Identifier ':' Type ;
+Function    = "fn" Identifier '(' (Param ',')* Param? ')' ('->' Ty)? Block? ;
+Param       = Mutability Identifier ':' Ty ;
 
 Struct      = "struct" Identifier (StructTuple | StructBody)?;
 StructBody  = '{' (StructMember ',')* StructMember? '}' ;
 StructTuple = TyTuple ;
-StructMember = Visibility Identifier ':' Type ;
+StructMember = Visibility Identifier ':' Ty ;
 
 Enum        = "enum" Identifier '{' (Variant ',')* Variant? '}' ;
 Variant     = Identifier (VarStruct | VarTuple | VarCLike)? ;
@@ -40,7 +40,7 @@ VarStruct   = '{' (StructMember ',')* StructMember? '}' ;
 VarTuple    = TyTuple ;
 VarCLike    = '=' INTEGER ;
 
-Alias       = "type" Ty ('=' Ty)? ';' ;
+Alias       = "type" Identifier ('=' Ty)? ';' ;
 
 Impl        = "impl" Path '{' Item* '}' ;
 (* TODO: Impl Trait for Target*)
@@ -51,8 +51,9 @@ Ty          = Never | Empty | Path | TyTuple | TyRef | TyFn ;
 Never       = '!' ;
 Empty       = '(' ')' ;
 TyTuple     = '(' (Ty ',')* Ty? ')' ;
-TyRef       = ('&' | '&&')* Path ;
-TyFn        = "fn" TyTuple (-> Ty)? ;
+TyRef       = Amps* Path ;
+Amps        = '&' | '&&' ;
+TyFn        = "fn" TyTuple ('->' Ty)? ;
 
 
 (* path *)
@@ -74,24 +75,19 @@ Bool        = "true" | "false" ;
 
 
 (* expr *)
-ExprKind    = Assign  | Compare | Range  | Logic    | Bitwise | Shift
-            | Factor  | Term    | Unary  | Member   | Call    | Index
-            | Path    | Literal | Array  | ArrayRep | AddrOf
-            | Block   | Group    
-            | While   | If      | For    | Break    | Return  | Continue ;
 
 Expr        = Assign ;
 
 Assign      = Path (AssignKind  Assign ) | Compare ;
 
-Binary      = Compare | Range | Logic  | Bitwise | Shift | Factor | Term ;
+(* Binary      = Compare | Range | Logic | Bitwise | Shift | Factor | Term ; *)
 Compare     = Range    (CompareOp Range  )* ;
 Range       = Logic    (RangeOp   Logic  )* ;
 Logic       = Bitwise  (LogicOp   Bitwise)* ;
 Bitwise     = Shift    (BitwiseOp Shift  )* ;
 Shift       = Factor   (ShiftOp   Factor )* ;
 Factor      = Term     (FactorOp  Term   )* ;
-Term        = Unary    (FactorOp  Unary  )* ;
+Term        = Unary    (TermOp    Unary  )* ;
 
 Unary       = (UnaryKind)* Member ;
 
@@ -111,13 +107,12 @@ Literal     = STRING | CHARACTER | FLOAT | INTEGER | Bool ;
 Array       = '[' (Expr ',')* Expr? ']' ;
 ArrayRep    = '[' Expr ';' Expr ']' ;
 
-AddrOf      = ('&' | '&&')* Mutability? Expr ;
+AddrOf      = Amps Amps* Mutability Expr ;
 
 Block       = '{' Stmt* '}';
 
-Group       = '(' (Empty | Expr | Tuple) ')' ;
+Group       = Empty | '(' (Expr | Tuple) ')' ;
 Tuple       = (Expr ',')* Expr? ;
-Empty       = ;
 
 While       = "while" Expr Block Else ;
 If          = "if"    Expr Block Else ;
@@ -127,11 +122,8 @@ Break       = "break"  Expr ;
 Return      = "return" Expr ;
 Continue    = "continue" ;
 
-AssignKind  =  '=' | '+=' | '-=' | '*=' | '/=' |
-              '&=' | '|=' | '^=' |'<<=' |'>>=' ;
+AssignKind  =  '=' | '+=' | '-=' | '*=' | '/=' | '&=' | '|=' | '^=' |'<<=' |'>>=' ;
 
-BinaryKind  = CompareOp | RangeOp | LogicOp  | BitwiseOp 
-            | ShiftOp   | TermOp  | FactorOp ;
 CompareOp   =  '<' | '<=' | '==' | '!=' | '>=' | '>' ;
 RangeOp     = '..' | '..=' ;
 LogicOp     = '&&' | '||' | '^^' ;

libconlang/.gitignore

@@ -1 +0,0 @@
-/target

libconlang/Cargo.toml

@@ -1,15 +0,0 @@
-[package]
-name = "conlang"
-description = "The Conlang Programming Language"
-keywords = ["interpreter", "programming", "language"]
-authors.workspace = true
-version.workspace = true
-edition.workspace = true
-license.workspace = true
-publish.workspace = true
-repository.workspace = true
-
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
-[dependencies]
-unicode-xid = "0.2.4"

libconlang/src/lib.rs

@@ -1,20 +0,0 @@
-//! Conlang is an expression-based programming language with similarities to Rust and Python
-#![warn(clippy::all)]
-#![feature(decl_macro)]
-
-pub mod common;
-
-pub mod token;
-
-pub mod ast;
-
-pub mod lexer;
-
-pub mod parser;
-
-pub mod resolver;
-
-pub mod interpreter;
-
-#[cfg(test)]
-mod tests;

libconlang/src/resolver.rs

@@ -1,916 +0,0 @@
-//! Extremely early WIP of a static type-checker/resolver
-//!
-//! This will hopefully become a fully fledged static resolution pass in the future
-use std::collections::HashMap;
-
-use scopeguard::Scoped;
-pub mod scopeguard {
-    //! Implements a generic RAII scope-guard
-
-    use std::ops::{Deref, DerefMut};
-
-    pub trait Scoped: Sized {
-        fn frame(&mut self) -> Guard<Self> {
-            Guard::new(self)
-        }
-        ///
-        fn enter_scope(&mut self);
-        fn exit_scope(&mut self);
-    }
-
-    pub struct Guard<'scope, T: Scoped> {
-        inner: &'scope mut T,
-    }
-    impl<'scope, T: Scoped> Guard<'scope, T> {
-        pub fn new(inner: &'scope mut T) -> Self {
-            inner.enter_scope();
-            Self { inner }
-        }
-    }
-    impl<'scope, T: Scoped> Deref for Guard<'scope, T> {
-        type Target = T;
-        fn deref(&self) -> &Self::Target {
-            self.inner
-        }
-    }
-    impl<'scope, T: Scoped> DerefMut for Guard<'scope, T> {
-        fn deref_mut(&mut self) -> &mut Self::Target {
-            self.inner
-        }
-    }
-    impl<'scope, T: Scoped> Drop for Guard<'scope, T> {
-        fn drop(&mut self) {
-            self.inner.exit_scope()
-        }
-    }
-}
-
-/// Prints like [println] if `debug_assertions` are enabled
-macro debugln($($t:tt)*) {
-    if cfg!(debug_assertions) {
-        println!($($t)*);
-    }
-}
-macro debug($($t:tt)*) {
-    if cfg!(debug_assertions) {
-        print!($($t)*);
-    }
-}
-
-use ty::Type;
-pub mod ty {
-    //! Describes the type of a [Variable](super::Variable)
-    use std::fmt::Display;
-
-    /// Describes the type of a [Variable](super::Variable)
-    #[derive(Clone, Debug, Default, PartialEq, Eq, PartialOrd, Ord)]
-    pub enum Type {
-        #[default]
-        Empty,
-        Int,
-        Bool,
-        Char,
-        String,
-        Float,
-        Fn {
-            args: Vec<Type>,
-            ret: Box<Type>,
-        },
-        Range(Box<Type>),
-        Tuple(Vec<Type>),
-        Never,
-        /// [Inferred](Type::Inferred) is for error messages. DO NOT CONSTRUCT
-        Inferred,
-        Generic(String),
-        /// A function with a single parameter of [Type::ManyInferred]
-        /// is assumed to always be correct.
-        ManyInferred,
-    }
-    impl Type {
-        fn is_empty(&self) -> bool {
-            self == &Type::Empty
-        }
-    }
-    impl Display for Type {
-        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-            match self {
-                Type::Empty => "Empty".fmt(f),
-                Type::Int => "integer".fmt(f),
-                Type::Bool => "bool".fmt(f),
-                Type::Char => "char".fmt(f),
-                Type::String => "String".fmt(f),
-                Type::Float => "float".fmt(f),
-                // TODO: clean this up
-                Type::Fn { args, ret } => {
-                    "fn (".fmt(f)?;
-                    let mut args = args.iter();
-                    if let Some(arg) = args.next() {
-                        arg.fmt(f)?;
-                    }
-                    for arg in args {
-                        write!(f, ", {arg}")?
-                    }
-                    ")".fmt(f)?;
-                    if !ret.is_empty() {
-                        write!(f, " -> {ret}")?;
-                    }
-                    Ok(())
-                }
-                Type::Range(t) => write!(f, "{t}..{t}"),
-                Type::Tuple(t) => {
-                    "(".fmt(f)?;
-                    for (idx, ty) in t.iter().enumerate() {
-                        if idx > 0 {
-                            ", ".fmt(f)?;
-                        }
-                        ty.fmt(f)?;
-                    }
-                    ")".fmt(f)
-                }
-                Type::Never => "!".fmt(f),
-                Type::Inferred => "_".fmt(f),
-                Type::Generic(name) => write!(f, "<{name}>"),
-                Type::ManyInferred => "..".fmt(f),
-            }
-        }
-    }
-}
-
-/// Describes the life-cycle of a [Variable]: Whether it's bound, typed, or initialized
-#[derive(Clone, Debug, Default, PartialEq, Eq, PartialOrd, Ord)]
-pub enum Status {
-    #[default]
-    Bound,
-    Uninitialized(Type),
-    Initialized(Type),
-}
-impl Status {
-    /// Performs type-checking for a [Variable] assignment
-    pub fn assign(&mut self, ty: &Type) -> TyResult<()> {
-        match self {
-            // Variable uninitialized: initialize it
-            Status::Bound => {
-                *self = Status::Initialized(ty.clone());
-                Ok(())
-            }
-            // Typecheck ok! Reuse the allocation for t
-            Status::Uninitialized(t) if t == ty => {
-                *self = Status::Initialized(std::mem::take(t));
-                Ok(())
-            }
-            Status::Initialized(t) if t == ty => Ok(()),
-            // Typecheck not ok.
-            Status::Uninitialized(e) | Status::Initialized(e) => {
-                Err(Error::TypeMismatch { want: ty.clone(), got: e.clone() })
-            }
-        }
-    }
-}
-#[derive(Clone, Debug, Default, PartialEq, Eq, PartialOrd, Ord)]
-pub struct Variable {
-    /// The unique, global index of this variable
-    pub index: usize,
-    /// The [Status] of this variable
-    pub status: Status,
-    /// The mutability qualifier of this variable
-    pub mutable: bool,
-}
-impl Variable {
-    /// Constructs a new variable with the provided index and mutability
-    pub fn new(index: usize, mutable: bool) -> Self {
-        Self { index, mutable, ..Default::default() }
-    }
-    /// Performs a type-checked assignment on self
-    pub fn assign(&mut self, name: &str, ty: &Type) -> TyResult<()> {
-        let Variable { index, status, mutable } = self;
-        debug!("Typecheck for {name} #{index}: ");
-        let out = match (status, mutable) {
-            // Variable uninitialized: initialize it
-            (Status::Bound, _) => {
-                self.status = Status::Initialized(ty.clone());
-                Ok(())
-            }
-            // Typecheck ok! Reuse the allocation for t
-            (Status::Uninitialized(t), _) if t == ty => {
-                self.status = Status::Initialized(std::mem::take(t));
-                Ok(())
-            }
-            // Reassignment of mutable variable is ok
-            (Status::Initialized(t), true) if t == ty => Ok(()),
-            // Reassignment of immutable variable is not ok
-            (Status::Initialized(_), false) => Err(Error::ImmutableAssign(name.into(), *index)),
-            // Typecheck not ok.
-            (Status::Uninitialized(e) | Status::Initialized(e), _) => {
-                Err(Error::TypeMismatch { want: ty.clone(), got: e.clone() })
-            }
-        };
-        match &out {
-            Ok(_) => debugln!("Ok! ({ty})"),
-            Err(e) => debugln!("Error: {e:?}"),
-        }
-        out
-    }
-    /// Performs the type-checking for a modifying assignment
-    pub fn modify_assign(&self, name: &str, ty: &Type) -> TyResult<()> {
-        let Variable { index, status, mutable } = &self;
-        match (status, mutable) {
-            (Status::Initialized(t), true) if t == ty => Ok(()),
-            (Status::Initialized(t), true) => {
-                Err(Error::TypeMismatch { want: t.clone(), got: ty.clone() })
-            }
-            (Status::Initialized(_), false) => Err(Error::ImmutableAssign(name.into(), *index)),
-            (..) => Err(Error::Uninitialized(name.into(), *index)),
-        }
-    }
-}
-
-/*
-    THE BIG IDEA:
-    - Each `let` statement binds a *different* variable.
-      - Shadowing is a FEATURE
-    - Traversing the tree before program launch allows the Resolver to assign
-      an index to each variable usage in the scope-tree
-    - These indices allow constant-time variable lookup in the interpreter!!!
-    - The added type-checking means fewer type errors!
-
-    REQUIREMENTS FOR FULL TYPE-CHECKING:
-    - Meaningful type expressions in function declarations
-
-    NECESSARY CONSIDERATIONS:
-    - Variable binding happens AFTER the initialization expression is run.
-      - If a variable is *entirely* unbound before being referenced,
-        it'll still error.
-      - This is *intentional*, and ALLOWS shadowing previous variables.
-      - In my experience, this is almost NEVER an error :P
-*/
-
-#[derive(Clone, Debug, Default)]
-pub struct Scope {
-    /// A monotonically increasing counter of variable declarations
-    count: usize,
-    /// A dictionary keeping track of type and lifetime information
-    vars: HashMap<String, Variable>,
-}
-impl Scope {
-    /// Bind a [Variable] in Scope
-    pub fn insert(&mut self, name: &str, index: usize, mutable: bool) {
-        self.count += 1;
-        self.vars
-            .insert(name.to_string(), Variable::new(index, mutable));
-    }
-    /// Returns a reference to a [Variable], if `name` is bound
-    pub fn get(&self, name: &str) -> Option<&Variable> {
-        self.vars.get(name)
-    }
-    /// Returns a mutable reference to a [Variable], if `name` is bound
-    pub fn get_mut(&mut self, name: &str) -> Option<&mut Variable> {
-        self.vars.get_mut(name)
-    }
-}
-/// Implements a dynamically scoped namespace
-#[derive(Clone, Debug, Default)]
-pub struct Module {
-    modules: HashMap<String, Module>,
-    vars: HashMap<String, Variable>,
-}
-impl Module {
-    pub fn insert_var(&mut self, name: &str, index: usize, mutable: bool) -> TyResult<()> {
-        if self
-            .vars
-            .insert(name.into(), Variable::new(index, mutable))
-            .is_some()
-        {
-            Err(Error::NonUniqueInModule(name.into()))?;
-        }
-        Ok(())
-    }
-    pub fn insert_module(&mut self, name: String, module: Module) -> TyResult<()> {
-        if self.modules.insert(name.clone(), module).is_some() {
-            Err(Error::NonUniqueInModule(name + "(module)"))?
-        }
-        Ok(())
-    }
-    /// Returns a reference to a [Variable] in this Module, if `name` is bound
-    pub fn get(&self, name: &str) -> Option<&Variable> {
-        self.vars.get(name)
-    }
-    /// Returns a mutable reference to a [Variable] in this Module, if `name` is bound
-    pub fn get_mut(&mut self, name: &str) -> Option<&mut Variable> {
-        self.vars.get_mut(name)
-    }
-
-    pub fn resolve_get(&self, name: &str, path: &[String]) -> Option<&Variable> {
-        if path.is_empty() {
-            return self.get(name);
-        }
-        let module = self.modules.get(&path[0])?;
-        module
-            .resolve_get(name, &path[1..])
-            .or_else(|| self.get(name))
-    }
-    // Returns a reference to the module at a specified path
-    pub fn resolve(&self, path: &[String]) -> TyResult<&Module> {
-        if path.is_empty() {
-            return Ok(self);
-        }
-        let module = self
-            .modules
-            .get(&path[0])
-            .ok_or_else(|| Error::Unbound(path[0].clone()))?;
-        module.resolve(&path[1..])
-    }
-    /// Returns a mutable reference to a Module if one is bound
-    pub fn resolve_mut(&mut self, path: &[String]) -> TyResult<&mut Module> {
-        if path.is_empty() {
-            return Ok(self);
-        }
-        let module = self
-            .modules
-            .get_mut(&path[0])
-            .ok_or_else(|| Error::Unbound(path[0].clone()))?;
-        module.resolve_mut(&path[1..])
-    }
-}
-
-#[derive(Clone, Debug)]
-pub struct Resolver {
-    /// A monotonically increasing counter of variable declarations
-    count: usize,
-    /// A stack of nested scopes *inside* a function
-    scopes: Vec<Scope>,
-    /// A stack of nested scopes *outside* a function
-    // TODO: Record the name of the module, and keep a stack of the current module
-    // for name resolution
-    modules: Module,
-    /// Describes the current path
-    module: Vec<String>,
-    /// A stack of types
-    types: Vec<Type>,
-}
-
-impl Scoped for Resolver {
-    fn enter_scope(&mut self) {
-        self.enter_scope();
-    }
-    fn exit_scope(&mut self) {
-        self.exit_scope();
-    }
-}
-
-impl Default for Resolver {
-    fn default() -> Self {
-        let mut new = Self {
-            count: Default::default(),
-            scopes: vec![Default::default()],
-            modules: Default::default(),
-            module: Default::default(),
-            types: Default::default(),
-        };
-        new.register_builtin("print", &[], &[Type::ManyInferred], Type::Empty)
-            .expect("print should not be bound in new Resolver");
-        new
-    }
-}
-
-impl Resolver {
-    pub fn new() -> Self {
-        Default::default()
-    }
-    /// Register a built-in function into the top-level module
-    pub fn register_builtin(
-        &mut self,
-        name: &str,
-        path: &[String],
-        args: &[Type],
-        ret: Type,
-    ) -> TyResult<()> {
-        let module = self.modules.resolve_mut(path)?;
-        module.vars.insert(
-            name.into(),
-            Variable {
-                index: 0,
-                status: Status::Initialized(Type::Fn { args: args.into(), ret: ret.into() }),
-                mutable: false,
-            },
-        );
-        Ok(())
-    }
-    /// Enters a Module Scope
-    pub fn enter_module(&mut self, name: &str) -> TyResult<()> {
-        let module = self.modules.resolve_mut(&self.module)?;
-        module.insert_module(name.into(), Default::default())?;
-        self.module.push(name.into());
-        Ok(())
-    }
-    /// Exits a Module Scope
-    pub fn exit_module(&mut self) -> Option<String> {
-        // Modules stay registered
-        self.module.pop()
-    }
-    /// Enters a Block Scope
-    pub fn enter_scope(&mut self) {
-        self.scopes.push(Default::default());
-    }
-    /// Exits a Block Scope, returning the value
-    pub fn exit_scope(&mut self) -> Option<usize> {
-        self.scopes.pop().map(|scope| scope.count)
-    }
-    /// Resolves a name to a [Variable]
-    pub fn get(&self, name: &str) -> TyResult<&Variable> {
-        if let Some(var) = self.scopes.iter().rev().find_map(|s| s.get(name)) {
-            return Ok(var);
-        }
-        self.modules
-            .resolve_get(name, &self.module)
-            .ok_or_else(|| Error::Unbound(name.into()))
-    }
-    /// Mutably resolves a name to a [Variable]
-    pub fn get_mut(&mut self, name: &str) -> TyResult<&mut Variable> {
-        if let Some(var) = self.scopes.iter_mut().rev().find_map(|s| s.get_mut(name)) {
-            return Ok(var);
-        }
-        self.modules
-            .resolve_mut(&self.module)?
-            .get_mut(name)
-            .ok_or_else(|| Error::Unbound(name.into()))
-    }
-    /// Binds a name in the current lexical scope
-    pub fn insert_scope(&mut self, name: &str, mutable: bool) -> TyResult<usize> {
-        self.count += 1;
-        self.scopes
-            .last_mut()
-            .ok_or_else(|| panic!("Stack underflow in resolver?"))?
-            .insert(name, self.count, mutable);
-        Ok(self.count)
-    }
-    /// Binds a name in the current module
-    pub fn insert_module(&mut self, name: &str, mutable: bool) -> TyResult<usize> {
-        self.count += 1;
-        self.modules
-            .resolve_mut(&self.module)?
-            .insert_var(name, self.count, mutable)?;
-        Ok(self.count)
-    }
-    /// Performs scoped type-checking of variables
-    pub fn assign(&mut self, name: &str, ty: &Type) -> TyResult<()> {
-        self.get_mut(name)?.assign(name, ty)
-    }
-}
-#[allow(unused_macros)]
-/// Manages a module scope
-/// ```rust,ignore
-/// macro module(self, name: &str, inner: {...}) -> Result<_, Error>
-/// ```
-macro module($self:ident, $name:tt, $inner:tt) {{
-    $self.enter_module($name)?;
-    #[allow(clippy::redundant_closure_call)]
-    let scope = (|| $inner)(); // This is pretty gross, but hey, try {} syntax is unstable too
-    $self.exit_module();
-    scope
-}}
-
-impl Resolver {
-    pub fn visit_empty(&mut self) -> TyResult<()> {
-        debugln!("Got Empty");
-        self.types.push(Type::Empty);
-        Ok(())
-    }
-}
-
-pub trait Resolve {
-    /// Performs variable resolution on self, and returns the type of self.
-    ///
-    /// For expressions, this is the type of the expression.
-    ///
-    /// For declarations, this is Empty.
-    fn resolve(&mut self, _resolver: &mut Resolver) -> TyResult<Type> {
-        Ok(Type::Empty)
-    }
-}
-mod ast1 {
-    // #![allow(deprecated)]
-    // use super::*;
-    // use crate::ast::preamble::*;
-    // impl Resolve for Start {
-    //     fn resolve(&mut self, resolver: &mut Resolver) -> TyResult<Type> {
-    //         let Self(program) = self;
-    //         program.resolve(resolver)
-    //     }
-    // }
-    // impl Resolve for Program {
-    //     fn resolve(&mut self, resolver: &mut Resolver) -> TyResult<Type> {
-    //         let Self(module) = self;
-    //         for decl in module {
-    //             decl.resolve(resolver)?;
-    //         }
-    //         // TODO: record the number of module-level assignments into the AST
-    //         Ok(Type::Empty)
-    //     }
-    // }
-    // impl Resolve for Stmt {
-    //     fn resolve(&mut self, resolver: &mut Resolver) -> TyResult<Type> {
-    //         match self {
-    //             Stmt::Let(value) => value.resolve(resolver),
-    //             Stmt::Fn(value) => value.resolve(resolver),
-    //             Stmt::Expr(value) => value.resolve(resolver),
-    //         }
-    //     }
-    // }
-    // impl Resolve for Let {
-    //     fn resolve(&mut self, resolver: &mut Resolver) -> TyResult<Type> {
-    //         let Let { name: Name { symbol: Identifier { name, index }, mutable, ty: _ }, init } =
-    //             self;
-    //         debugln!("ty> let {name} ...");
-    //         if let Some(init) = init {
-    //             let ty = init.resolve(resolver)?;
-    //             *index = Some(resolver.insert_scope(name, *mutable)?);
-    //             resolver.get_mut(name)?.assign(name, &ty)?;
-    //         } else {
-    //             resolver.insert_scope(name, *mutable)?;
-    //         }
-    //         Ok(Type::Empty)
-    //     }
-    // }
-    // impl Resolve for FnDecl {
-    //     fn resolve(&mut self, resolver: &mut Resolver) -> TyResult<Type> {
-    //         let FnDecl { name: Name { symbol: Identifier { name, index }, .. }, args, body } =
-    // self;         debugln!("ty> fn {name} ...");
-    //         // register the name at module scope
-    //         *index = Some(resolver.insert_module(name, false)?);
-    //         // create a new lexical scope
-    //         let scopes = std::mem::take(&mut resolver.scopes);
-    //         // type-check the function body
-    //         let out = {
-    //             let mut resolver = resolver.frame();
-    //             let mut evaluated_args = vec![];
-    //             for arg in args {
-    //                 evaluated_args.push(arg.resolve(&mut resolver)?)
-    //             }
-    //             let fn_decl = Type::Fn { args: evaluated_args.clone(), ret: Box::new(Type::Empty)
-    // };             resolver.get_mut(name)?.assign(name, &fn_decl)?;
-    //             module!(resolver, name, { body.resolve(&mut resolver) })
-    //         };
-    //         let _ = std::mem::replace(&mut resolver.scopes, scopes);
-    //         out
-    //     }
-    // }
-    // impl Resolve for Name {
-    //     fn resolve(&mut self, _resolver: &mut Resolver) -> TyResult<Type> {
-    //         Ok(Type::Empty)
-    //     }
-    // }
-    // impl Resolve for Block {
-    //     fn resolve(&mut self, resolver: &mut Resolver) -> TyResult<Type> {
-    //         let Block { let_count: _, statements, expr } = self;
-    //         let mut resolver = resolver.frame();
-    //         for stmt in statements {
-    //             stmt.resolve(&mut resolver)?;
-    //         }
-    //         expr.resolve(&mut resolver)
-    //     }
-    // }
-    // impl Resolve for Expr {
-    //     fn resolve(&mut self, resolver: &mut Resolver) -> TyResult<Type> {
-    //         let Expr(expr) = self;
-    //         expr.resolve(resolver)
-    //     }
-    // }
-
-    // impl Resolve for Operation {
-    //     fn resolve(&mut self, resolver: &mut Resolver) -> TyResult<Type> {
-    //         match self {
-    //             Operation::Assign(value) => value.resolve(resolver),
-    //             Operation::Binary(value) => value.resolve(resolver),
-    //             Operation::Unary(value) => value.resolve(resolver),
-    //             Operation::Call(value) => value.resolve(resolver),
-    //         }
-    //     }
-    // }
-    // impl Resolve for Assign {
-    //     fn resolve(&mut self, resolver: &mut Resolver) -> TyResult<Type> {
-    //         let Assign { target, operator, init } = self;
-    //         // Evaluate the initializer expression
-    //         let ty = init.resolve(resolver)?;
-    //         // Resolve the variable
-    //         match (operator, resolver.get_mut(&target.name)?) {
-    //             (
-    //                 operator::Assign::Assign,
-    //                 Variable { status: Status::Initialized(_), mutable: false, index },
-    //             ) => Err(Error::ImmutableAssign(target.name.clone(), *index)),
-    //             // TODO: make typing more expressive for modifying assignment
-    //             (_, variable) => variable
-    //                 .modify_assign(&target.name, &ty)
-    //                 .map(|_| Type::Empty),
-    //         }
-    //     }
-    // }
-
-    // impl Resolve for Binary {
-    //     fn resolve(&mut self, resolver: &mut Resolver) -> TyResult<Type> {
-    //         let Binary { first, other } = self;
-
-    //         let mut first = first.resolve(resolver)?;
-    //         for (op, other) in other {
-    //             let other = other.resolve(resolver)?;
-    //             first = resolver.resolve_binary_operator(first, other, op)?;
-    //         }
-    //         Ok(first)
-    //     }
-    // }
-    // impl Resolve for Unary {
-    //     fn resolve(&mut self, resolver: &mut Resolver) -> TyResult<Type> {
-    //         let Unary { operators, operand } = self;
-    //         let mut operand = operand.resolve(resolver)?;
-    //         for op in operators {
-    //             operand = resolver.resolve_unary_operator(operand, op)?;
-    //         }
-    //         Ok(operand)
-    //     }
-    // }
-    // /// Resolve [operator]s
-    // impl Resolver {
-    //     fn resolve_binary_operator(
-    //         &mut self,
-    //         first: Type,
-    //         other: Type,
-    //         op: &operator::Binary,
-    //     ) -> TyResult<Type> {
-    //         // TODO: check type compatibility for binary ops
-    //         // TODO: desugar binary ops into function calls, when member functions are a thing
-    //         eprintln!("Resolve binary operators {first} {op:?} {other}");
-    //         if first != other {
-    //             Err(Error::TypeMismatch { want: first, got: other })
-    //         } else {
-    //             Ok(first)
-    //         }
-    //     }
-    //     fn resolve_unary_operator(
-    //         &mut self,
-    //         operand: Type,
-    //         op: &operator::Unary,
-    //     ) -> TyResult<Type> {
-    //         // TODO: Allow more expressive unary operator type conversions
-    //         todo!("Resolve unary operators {op:?} {operand}")
-    //     }
-    // }
-    // impl Resolve for Call {
-    //     fn resolve(&mut self, resolver: &mut Resolver) -> TyResult<Type> {
-    //         match self {
-    //             Call::FnCall(value) => value.resolve(resolver),
-    //             Call::Primary(value) => value.resolve(resolver),
-    //         }
-    //     }
-    // }
-    // impl Resolve for FnCall {
-    //     fn resolve(&mut self, resolver: &mut Resolver) -> TyResult<Type> {
-    //         let FnCall { callee, args } = self;
-    //         let mut callee = callee.resolve(resolver)?;
-    //         for argset in args {
-    //             // arguments should always be a tuple here
-    //             let arguments = argset.resolve(resolver)?;
-    //             let Type::Tuple(arguments) = arguments else {
-    //                 Err(Error::TypeMismatch {
-    //                     want: Type::Tuple(vec![Type::ManyInferred]),
-    //                     got: arguments,
-    //                 })?
-    //             };
-    //             // Verify that the callee is a function, and the arguments match.
-    //             // We need the arguments
-    //             let Type::Fn { args, ret } = callee else {
-    //                 return Err(Error::TypeMismatch {
-    //                     want: Type::Fn { args: arguments, ret: Type::Inferred.into() },
-    //                     got: callee,
-    //                 })?;
-    //             };
-    //             for (want, got) in args.iter().zip(&arguments) {
-    //                 // TODO: verify generics
-    //                 if let Type::Generic(_) = want {
-    //                     continue;
-    //                 }
-    //                 if want != got {
-    //                     return Err(Error::TypeMismatch {
-    //                         want: Type::Fn { args: arguments, ret: Type::Inferred.into() },
-    //                         got: Type::Fn { args, ret },
-    //                     })?;
-    //                 }
-    //             }
-    //             callee = *ret;
-    //         }
-    //         Ok(callee)
-    //     }
-    // }
-    // impl Resolve for Primary {
-    //     fn resolve(&mut self, resolver: &mut Resolver) -> TyResult<Type> {
-    //         match self {
-    //             Primary::Identifier(value) => value.resolve(resolver),
-    //             Primary::Literal(value) => value.resolve(resolver),
-    //             Primary::Block(value) => value.resolve(resolver),
-    //             Primary::Group(value) => value.resolve(resolver),
-    //             Primary::Branch(value) => value.resolve(resolver),
-    //         }
-    //     }
-    // }
-
-    // impl Resolve for Group {
-    //     fn resolve(&mut self, resolver: &mut Resolver) -> TyResult<Type> {
-    //         match self {
-    //             Group::Tuple(tuple) => tuple.resolve(resolver),
-    //             Group::Single(expr) => expr.resolve(resolver),
-    //             Group::Empty => Ok(Type::Empty),
-    //         }
-    //     }
-    // }
-
-    // impl Resolve for Tuple {
-    //     fn resolve(&mut self, resolver: &mut Resolver) -> TyResult<Type> {
-    //         let Tuple { elements } = self;
-    //         let mut types = vec![];
-    //         for expr in elements.iter_mut() {
-    //             types.push(expr.resolve(resolver)?);
-    //         }
-    //         Ok(Type::Tuple(types))
-    //     }
-    // }
-
-    // impl Resolve for Identifier {
-    //     fn resolve(&mut self, resolver: &mut Resolver) -> TyResult<Type> {
-    //         let Identifier { name, index: id_index } = self;
-    //         let Variable { index, status, .. } = resolver.get(name)?;
-    //         *id_index = Some(*index);
-    //         let ty = match status {
-    //             Status::Initialized(t) => t,
-    //             _ => Err(Error::Uninitialized(name.to_owned(), *index))?,
-    //         };
-    //         debugln!("ty> Resolved {} #{index}: {ty}", name);
-    //         Ok(ty.to_owned())
-    //     }
-    // }
-    // impl Resolve for Literal {
-    //     fn resolve(&mut self, _resolver: &mut Resolver) -> TyResult<Type> {
-    //         Ok(match self {
-    //             Literal::String(_) => Type::String,
-    //             Literal::Char(_) => Type::Char,
-    //             Literal::Bool(_) => Type::Bool,
-    //             Literal::Float(_) => Type::Float,
-    //             Literal::Int(_) => Type::Int,
-    //         })
-    //     }
-    // }
-
-    // impl Resolve for Flow {
-    //     fn resolve(&mut self, resolver: &mut Resolver) -> TyResult<Type> {
-    //         // TODO: Finish this
-    //         match self {
-    //             Flow::While(value) => value.resolve(resolver),
-    //             Flow::If(value) => value.resolve(resolver),
-    //             Flow::For(value) => value.resolve(resolver),
-    //             Flow::Continue(value) => value.resolve(resolver),
-    //             Flow::Return(value) => value.resolve(resolver),
-    //             Flow::Break(value) => value.resolve(resolver),
-    //         }
-    //     }
-    // }
-    // impl Resolve for While {
-    //     fn resolve(&mut self, resolver: &mut Resolver) -> TyResult<Type> {
-    //         // TODO: Finish this
-    //         // Visit else first, save that to a break-pattern stack in the Resolver,
-    //         // and check it inside Break::resolve()
-    //         let While { cond, body, else_ } = self;
-    //         cond.resolve(resolver)?; // must be Type::Bool
-    //         body.resolve(resolver)?; // discard
-    //         else_.resolve(resolver) // compare with returns inside body
-    //     }
-    // }
-    // impl Resolve for If {
-    //     fn resolve(&mut self, resolver: &mut Resolver) -> TyResult<Type> {
-    //         let If { cond, body, else_ } = self;
-    //         let cond = cond.resolve(resolver)?;
-    //         if Type::Bool != cond {
-    //             return Err(Error::TypeMismatch { want: Type::Bool, got: cond });
-    //         }
-    //         let body_ty = body.resolve(resolver)?;
-    //         let else_ty = else_.resolve(resolver)?;
-    //         if body_ty == else_ty {
-    //             Ok(body_ty)
-    //         } else {
-    //             Err(Error::TypeMismatch { want: body_ty, got: else_ty })
-    //         }
-    //     }
-    // }
-
-    // impl Resolve for For {
-    //     fn resolve(&mut self, resolver: &mut Resolver) -> TyResult<Type> {
-    //         let For { var: Identifier { name, index }, iter, body, else_ } = self;
-    //         debugln!("> for {name} in ...");
-    //         // Visit the iter expression and get its type
-    //         let range = iter.resolve(resolver)?;
-    //         let ty = match range {
-    //             Type::Range(t) => t,
-    //             got => Err(Error::TypeMismatch { want: Type::Range(Type::Inferred.into()), got
-    // })?,         };
-    //         let body_ty = {
-    //             let mut resolver = resolver.frame();
-    //             // bind the variable in the loop scope
-    //             *index = Some(resolver.insert_scope(name, false)?);
-    //             resolver.get_mut(name)?.assign(name, &ty)?;
-    //             body.resolve(&mut resolver)
-    //         }?;
-    //         // visit the else block
-    //         let else_ty = else_.resolve(resolver)?;
-    //         if body_ty != else_ty {
-    //             Err(Error::TypeMismatch { want: body_ty, got: else_ty })
-    //         } else {
-    //             Ok(body_ty)
-    //         }
-    //     }
-    // }
-    // impl Resolve for Else {
-    //     fn resolve(&mut self, resolver: &mut Resolver) -> TyResult<Type> {
-    //         let Else { expr } = self;
-    //         expr.resolve(resolver)
-    //     }
-    // }
-
-    // impl Resolve for Continue {
-    //     fn resolve(&mut self, _resolver: &mut Resolver) -> TyResult<Type> {
-    //         // TODO: Finish control flow
-    //         Ok(Type::Never)
-    //     }
-    // }
-    // impl Resolve for Break {
-    //     fn resolve(&mut self, resolver: &mut Resolver) -> TyResult<Type> {
-    //         // TODO: Finish control flow
-    //         let Break { expr } = self;
-    //         expr.resolve(resolver)
-    //     }
-    // }
-    // impl Resolve for Return {
-    //     fn resolve(&mut self, resolver: &mut Resolver) -> TyResult<Type> {
-    //         // TODO: Finish control flow
-    //         let Return { expr } = self;
-    //         expr.resolve(resolver)
-    //     }
-    // }
-}
-
-mod ast {
-    #![allow(unused_imports)]
-    use crate::ast::*;
-}
-
-// heakc yea man, generics
-impl<T: Resolve> Resolve for Option<T> {
-    fn resolve(&mut self, resolver: &mut Resolver) -> TyResult<Type> {
-        match self {
-            Some(t) => t.resolve(resolver),
-            None => Ok(Type::Empty),
-        }
-    }
-}
-impl<T: Resolve> Resolve for Box<T> {
-    fn resolve(&mut self, resolver: &mut Resolver) -> TyResult<Type> {
-        self.as_mut().resolve(resolver)
-    }
-}
-
-use error::{Error, TyResult};
-pub mod error {
-    use super::Type;
-    use std::fmt::Display;
-
-    pub type TyResult<T> = Result<T, Error>;
-
-    impl std::error::Error for Error {}
-    #[derive(Clone, Debug)]
-    pub enum Error {
-        StackUnderflow,
-        // types
-        TypeMismatch { want: Type, got: Type },
-        // modules
-        NonUniqueInModule(String),
-        // lifetimes
-        Uninitialized(String, usize),
-        ImmutableAssign(String, usize),
-        Unbound(String),
-    }
-    impl Display for Error {
-        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-            match self {
-                Error::StackUnderflow => "Stack underflow in Resolver".fmt(f),
-                Error::TypeMismatch { want, got } => {
-                    write!(f, "Type error: {want} != {got}")
-                }
-                Error::ImmutableAssign(name, index) => {
-                    write!(f, "Cannot mutate immutable variable {name}(#{index})")
-                }
-                Error::Uninitialized(name, index) => {
-                    write!(f, "{name}(#{index}) was accessed before initialization")
-                }
-                Error::Unbound(name) => write!(f, "{name} not bound before use."),
-                Error::NonUniqueInModule(name) => {
-                    write!(f, "Name {name} not unique at module scope!")
-                }
-            }
-        }
-    }
-}

libconlang/src/tests.rs

@@ -1,181 +0,0 @@
-mod token {
-    // TODO
-}
-mod ast {
-    // TODO
-}
-mod lexer {
-    #[allow(unused_imports)]
-    use crate::{lexer::Lexer, token::preamble::*};
-
-    macro test_lexer_output_type  ($($f:ident {$($test:expr => $expect:expr),*$(,)?})*) {$(
-        #[test]
-        fn $f() {$(
-            assert_eq!(
-                Lexer::new($test)
-                    .into_iter()
-                    .map(|t| t.unwrap().ty())
-                    .collect::<Vec<_>>(),
-                dbg!($expect)
-            );
-        )*}
-    )*}
-
-    macro test_lexer_data_type  ($($f:ident {$($test:expr => $expect:expr),*$(,)?})*) {$(
-        #[test]
-        fn $f() {$(
-            assert_eq!(
-                Lexer::new($test)
-                    .into_iter()
-                    .map(|t| t.unwrap().into_data())
-                    .collect::<Vec<_>>(),
-                dbg!($expect)
-            );
-        )*}
-    )*}
-
-    /// Convert an `[ expr, ... ]` into a `[ *, ... ]`
-    macro td ($($id:expr),*) {
-        [$($id.into()),*]
-    }
-
-    mod ident {
-        use super::*;
-        macro ident ($($id:literal),*) {
-            [$(Data::Identifier($id.into())),*]
-        }
-        test_lexer_data_type! {
-            underscore { "_ _" => ident!["_", "_"] }
-            unicode { "_ε ε_" => ident!["_ε", "ε_"] }
-            many_underscore { "____________________________________" =>
-            ident!["____________________________________"] }
-        }
-    }
-    mod keyword {
-        use super::*;
-        macro kw($($k:ident),*) {
-            [ $(Type::Keyword(Keyword::$k),)* ]
-        }
-        test_lexer_output_type! {
-            kw_break { "break break" => kw![Break, Break] }
-            kw_continue { "continue continue" => kw![Continue, Continue] }
-            kw_else { "else else" => kw![Else, Else] }
-            kw_false { "false false" => kw![False, False] }
-            kw_for { "for for" => kw![For, For] }
-            kw_fn { "fn fn" => kw![Fn, Fn] }
-            kw_if { "if if" => kw![If, If] }
-            kw_in { "in in" => kw![In, In] }
-            kw_let { "let let" => kw![Let, Let] }
-            kw_return { "return return" => kw![Return, Return] }
-            kw_true { "true true" => kw![True, True] }
-            kw_while { "while while" => kw![While, While] }
-            keywords { "break continue else false for fn if in let return true while" =>
-                kw![Break, Continue, Else, False, For, Fn, If, In, Let, Return, True, While] }
-        }
-    }
-    mod integer {
-        use super::*;
-        test_lexer_data_type! {
-            hex {
-                "0x0 0x1 0x15 0x2100 0x8000" =>
-                td![0x0, 0x1, 0x15, 0x2100, 0x8000]
-            }
-            dec {
-                "0d0 0d1 0d21 0d8448 0d32768" =>
-                td![0, 0x1, 0x15, 0x2100, 0x8000]
-            }
-            oct {
-                "0o0 0o1 0o25 0o20400 0o100000" =>
-                td![0x0, 0x1, 0x15, 0x2100, 0x8000]
-            }
-            bin {
-                "0b0 0b1 0b10101 0b10000100000000 0b1000000000000000" =>
-                td![0x0, 0x1, 0x15, 0x2100, 0x8000]
-            }
-            baseless {
-                "0 1 21 8448 32768" =>
-                td![0x0, 0x1, 0x15, 0x2100, 0x8000]
-            }
-        }
-    }
-    mod string {
-        use super::*;
-        test_lexer_data_type! {
-            empty_string {
-                "\"\"" =>
-                td![String::from("")]
-            }
-            unicode_string {
-                "\"I 💙 🦈!\"" =>
-                td![String::from("I 💙 🦈!")]
-            }
-            escape_string {
-                " \"This is a shark: \\u{1f988}\" " =>
-                td![String::from("This is a shark: 🦈")]
-            }
-        }
-    }
-    mod punct {
-        use super::*;
-        test_lexer_output_type! {
-            l_curly   { "{ {"   => [ Type::LCurly, Type::LCurly ] }
-            r_curly   { "} }"   => [ Type::RCurly, Type::RCurly ] }
-            l_brack   { "[ ["   => [ Type::LBrack, Type::LBrack ] }
-            r_brack   { "] ]"   => [ Type::RBrack, Type::RBrack ] }
-            l_paren   { "( ("   => [ Type::LParen, Type::LParen ] }
-            r_paren   { ") )"   => [ Type::RParen, Type::RParen ] }
-            amp       { "& &"   => [ Type::Amp, Type::Amp ] }
-            amp_amp   { "&& &&" => [ Type::AmpAmp, Type::AmpAmp ] }
-            amp_eq    { "&= &=" => [ Type::AmpEq, Type::AmpEq ] }
-            arrow     { "-> ->" => [ Type::Arrow, Type::Arrow] }
-            at        { "@ @"   => [ Type::At, Type::At] }
-            backslash { "\\ \\" => [ Type::Backslash, Type::Backslash] }
-            bang      { "! !"   => [ Type::Bang, Type::Bang] }
-            bangbang  { "!! !!" => [ Type::BangBang, Type::BangBang] }
-            bangeq    { "!= !=" => [ Type::BangEq, Type::BangEq] }
-            bar       { "| |"   => [ Type::Bar, Type::Bar] }
-            barbar    { "|| ||" => [ Type::BarBar, Type::BarBar] }
-            bareq     { "|= |=" => [ Type::BarEq, Type::BarEq] }
-            colon     { ": :"   => [ Type::Colon, Type::Colon] }
-            comma     { ", ,"   => [ Type::Comma, Type::Comma] }
-            dot       { ". ."   => [ Type::Dot, Type::Dot] }
-            dotdot    { ".. .." => [ Type::DotDot, Type::DotDot] }
-            dotdoteq  { "..= ..=" => [ Type::DotDotEq, Type::DotDotEq] }
-            eq        { "= ="   => [ Type::Eq, Type::Eq] }
-            eqeq      { "== ==" => [ Type::EqEq, Type::EqEq] }
-            fatarrow  { "=> =>" => [ Type::FatArrow, Type::FatArrow] }
-            grave     { "` `"   => [ Type::Grave, Type::Grave] }
-            gt        { "> >"   => [ Type::Gt, Type::Gt] }
-            gteq      { ">= >=" => [ Type::GtEq, Type::GtEq] }
-            gtgt      { ">> >>" => [ Type::GtGt, Type::GtGt] }
-            gtgteq    { ">>= >>=" => [ Type::GtGtEq, Type::GtGtEq] }
-            hash      { "# #"   => [ Type::Hash, Type::Hash] }
-            lt        { "< <"   => [ Type::Lt, Type::Lt] }
-            lteq      { "<= <=" => [ Type::LtEq, Type::LtEq] }
-            ltlt      { "<< <<" => [ Type::LtLt, Type::LtLt] }
-            ltlteq    { "<<= <<=" => [ Type::LtLtEq, Type::LtLtEq] }
-            minus     { "- -"   => [ Type::Minus, Type::Minus] }
-            minuseq   { "-= -=" => [ Type::MinusEq, Type::MinusEq] }
-            plus      { "+ +"   => [ Type::Plus, Type::Plus] }
-            pluseq    { "+= +=" => [ Type::PlusEq, Type::PlusEq] }
-            question  { "? ?"   => [ Type::Question, Type::Question] }
-            rem       { "% %"   => [ Type::Rem, Type::Rem] }
-            remeq     { "%= %=" => [ Type::RemEq, Type::RemEq] }
-            semi      { "; ;"   => [ Type::Semi, Type::Semi] }
-            slash     { "/ /"   => [ Type::Slash, Type::Slash] }
-            slasheq   { "/= /=" => [ Type::SlashEq, Type::SlashEq] }
-            star      { "* *"   => [ Type::Star, Type::Star] }
-            stareq    { "*= *=" => [ Type::StarEq, Type::StarEq] }
-            tilde     { "~ ~"   => [ Type::Tilde, Type::Tilde] }
-            xor       { "^ ^"   => [ Type::Xor, Type::Xor] }
-            xoreq     { "^= ^=" => [ Type::XorEq, Type::XorEq] }
-            xorxor    { "^^ ^^" => [ Type::XorXor, Type::XorXor] }
-        }
-    }
-}
-mod parser {
-    // TODO
-}
-mod interpreter {
-    // TODO
-}

libconlang/src/token.rs

@@ -1,57 +0,0 @@
-//! # Token
-//!
-//! Stores a component of a file as a [Type], some [Data], and a line and column number
-
-pub mod token_data;
-pub mod token_type;
-pub mod preamble {
-    //! Common imports for working with [tokens](super)
-    pub use super::{
-        token_data::Data,
-        token_type::{Keyword, Type},
-        Token,
-    };
-}
-
-use token_data::Data;
-use token_type::Type;
-
-/// Contains a single unit of lexical information,
-/// and an optional bit of [Data]
-#[derive(Clone, Debug, PartialEq)]
-pub struct Token {
-    ty: Type,
-    data: Data,
-    line: u32,
-    col: u32,
-}
-impl Token {
-    /// Creates a new [Token] out of a [Type], [Data], line, and column.
-    pub fn new(ty: Type, data: impl Into<Data>, line: u32, col: u32) -> Self {
-        Self { ty, data: data.into(), line, col }
-    }
-    /// Casts this token to a new [Type]
-    pub fn cast(self, ty: Type) -> Self {
-        Self { ty, ..self }
-    }
-    /// Returns the [Type] of this token
-    pub fn ty(&self) -> Type {
-        self.ty
-    }
-    /// Returns a reference to this token's [Data]
-    pub fn data(&self) -> &Data {
-        &self.data
-    }
-    /// Converts this token into its inner [Data]
-    pub fn into_data(self) -> Data {
-        self.data
-    }
-    /// Returns the line where this token originated
-    pub fn line(&self) -> u32 {
-        self.line
-    }
-    /// Returns the column where this token originated
-    pub fn col(&self) -> u32 {
-        self.col
-    }
-}

libconlang/src/token/token_type.rs

@@ -1,239 +0,0 @@
-//! Stores a [Token's](super::Token) lexical information
-use std::{fmt::Display, str::FromStr};
-
-/// Stores a [Token's](super::Token) lexical information
-#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
-pub enum Type {
-    // Invalid syntax
-    Invalid,
-    // Any kind of comment
-    Comment,
-    // Any identifier
-    Identifier,
-    Keyword(Keyword),
-    // Literals
-    Integer,
-    Float,
-    String,
-    Character,
-    // Delimiters and punctuation
-    LCurly,     // {
-    RCurly,     // }
-    LBrack,     // [
-    RBrack,     // ]
-    LParen,     // (
-    RParen,     // )
-    Amp,        // &
-    AmpAmp,     // &&
-    AmpEq,      // &=
-    Arrow,      // ->
-    At,         // @
-    Backslash,  // \
-    Bang,       // !
-    BangBang,   // !!
-    BangEq,     // !=
-    Bar,        // |
-    BarBar,     // ||
-    BarEq,      // |=
-    Colon,      // :
-    ColonColon, // ::
-    Comma,      // ,
-    Dot,        // .
-    DotDot,     // ..
-    DotDotEq,   // ..=
-    Eq,         // =
-    EqEq,       // ==
-    FatArrow,   // =>
-    Grave,      // `
-    Gt,         // >
-    GtEq,       // >=
-    GtGt,       // >>
-    GtGtEq,     // >>=
-    Hash,       // #
-    HashBang,   // #!
-    Lt,         // <
-    LtEq,       // <=
-    LtLt,       // <<
-    LtLtEq,     // <<=
-    Minus,      // -
-    MinusEq,    // -=
-    Plus,       // +
-    PlusEq,     // +=
-    Question,   // ?
-    Rem,        // %
-    RemEq,      // %=
-    Semi,       // ;
-    Slash,      // /
-    SlashEq,    // /=
-    Star,       // *
-    StarEq,     // *=
-    Tilde,      // ~
-    Xor,        // ^
-    XorEq,      // ^=
-    XorXor,     // ^^
-}
-
-/// Represents a reserved word.
-#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
-pub enum Keyword {
-    Break,
-    Cl,
-    Const,
-    Continue,
-    Else,
-    Enum,
-    False,
-    For,
-    Fn,
-    If,
-    Impl,
-    In,
-    Let,
-    Mod,
-    Mut,
-    Pub,
-    Return,
-    SelfKw,
-    SelfTy,
-    Static,
-    Struct,
-    Super,
-    True,
-    Type,
-    While,
-}
-
-impl Display for Type {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        match self {
-            Type::Invalid => "invalid".fmt(f),
-            Type::Comment => "comment".fmt(f),
-            Type::Identifier => "identifier".fmt(f),
-            Type::Keyword(k) => k.fmt(f),
-            Type::Integer => "integer literal".fmt(f),
-            Type::Float => "float literal".fmt(f),
-            Type::String => "string literal".fmt(f),
-            Type::Character => "char literal".fmt(f),
-            Type::LCurly => "left curly".fmt(f),
-            Type::RCurly => "right curly".fmt(f),
-            Type::LBrack => "left brack".fmt(f),
-            Type::RBrack => "right brack".fmt(f),
-            Type::LParen => "left paren".fmt(f),
-            Type::RParen => "right paren".fmt(f),
-            Type::Amp => "and".fmt(f),
-            Type::AmpAmp => "and-and".fmt(f),
-            Type::AmpEq => "and-assign".fmt(f),
-            Type::Arrow => "arrow".fmt(f),
-            Type::At => "at".fmt(f),
-            Type::Backslash => "backslash".fmt(f),
-            Type::Bang => "bang".fmt(f),
-            Type::BangBang => "not-not".fmt(f),
-            Type::BangEq => "not equal to".fmt(f),
-            Type::Bar => "or".fmt(f),
-            Type::BarBar => "or-or".fmt(f),
-            Type::BarEq => "or-assign".fmt(f),
-            Type::Colon => "colon".fmt(f),
-            Type::ColonColon => "path separator".fmt(f),
-            Type::Comma => "comma".fmt(f),
-            Type::Dot => "dot".fmt(f),
-            Type::DotDot => "exclusive range".fmt(f),
-            Type::DotDotEq => "inclusive range".fmt(f),
-            Type::Eq => "assign".fmt(f),
-            Type::EqEq => "equal to".fmt(f),
-            Type::FatArrow => "fat arrow".fmt(f),
-            Type::Grave => "grave".fmt(f),
-            Type::Gt => "greater than".fmt(f),
-            Type::GtEq => "greater than or equal to".fmt(f),
-            Type::GtGt => "shift right".fmt(f),
-            Type::GtGtEq => "shift right-assign".fmt(f),
-            Type::Hash => "hash".fmt(f),
-            Type::HashBang => "shebang".fmt(f),
-            Type::Lt => "less than".fmt(f),
-            Type::LtEq => "less than or equal to".fmt(f),
-            Type::LtLt => "shift left".fmt(f),
-            Type::LtLtEq => "shift left-assign".fmt(f),
-            Type::Minus => "sub".fmt(f),
-            Type::MinusEq => "sub-assign".fmt(f),
-            Type::Plus => "add".fmt(f),
-            Type::PlusEq => "add-assign".fmt(f),
-            Type::Question => "huh?".fmt(f),
-            Type::Rem => "rem".fmt(f),
-            Type::RemEq => "rem-assign".fmt(f),
-            Type::Semi => "ignore".fmt(f),
-            Type::Slash => "div".fmt(f),
-            Type::SlashEq => "div-assign".fmt(f),
-            Type::Star => "star".fmt(f),
-            Type::StarEq => "star-assign".fmt(f),
-            Type::Tilde => "tilde".fmt(f),
-            Type::Xor => "xor".fmt(f),
-            Type::XorEq => "xor-assign".fmt(f),
-            Type::XorXor => "cat-ears".fmt(f),
-        }
-    }
-}
-
-impl Display for Keyword {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        match self {
-            Self::Break => "break".fmt(f),
-            Self::Cl => "cl".fmt(f),
-            Self::Const => "const".fmt(f),
-            Self::Continue => "continue".fmt(f),
-            Self::Else => "else".fmt(f),
-            Self::Enum => "enum".fmt(f),
-            Self::False => "false".fmt(f),
-            Self::For => "for".fmt(f),
-            Self::Fn => "fn".fmt(f),
-            Self::If => "if".fmt(f),
-            Self::Impl => "impl".fmt(f),
-            Self::In => "in".fmt(f),
-            Self::Let => "let".fmt(f),
-            Self::Mod => "mod".fmt(f),
-            Self::Mut => "mut".fmt(f),
-            Self::Pub => "pub".fmt(f),
-            Self::Return => "return".fmt(f),
-            Self::SelfKw => "self".fmt(f),
-            Self::SelfTy => "Self".fmt(f),
-            Self::Static => "static".fmt(f),
-            Self::Struct => "struct".fmt(f),
-            Self::Super => "super".fmt(f),
-            Self::True => "true".fmt(f),
-            Self::Type => "type".fmt(f),
-            Self::While => "while".fmt(f),
-        }
-    }
-}
-impl FromStr for Keyword {
-    /// [FromStr] can only fail when an identifier isn't a keyword
-    type Err = ();
-    fn from_str(s: &str) -> Result<Self, Self::Err> {
-        Ok(match s {
-            "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,
-            "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,
-            "while" => Self::While,
-            _ => Err(())?,
-        })
-    }
-}

sample-code/fib.cl

@@ -1,12 +1,13 @@
 // Calculate Fibonacci numbers
 
-fn main() -> i128 {
-    let num = 10;
-    print("fib(", num, "): ", fib(num));
+fn main() {
+    for num in 0..=30 {
+        print("fib(", num, ") = ", fib(num))
+    }
 }
 
 /// Implements the classic recursive definition of fib()
-fn fib(a: i128) -> i128 {
+fn fib(a: i64) -> i64 {
     if a > 1 {
         fib(a - 1) + fib(a - 2)
     } else {

stdlib/lib.cl

@@ -0,0 +1,11 @@
+//! # The Conlang Standard Library
+
+/// 32-bit signed integer type
+#[intrinsic = "i32"]
+type i32;
+
+/// 32-bit unsigned integer type
+#[intrinsic = "u32"]
+type u32;
+
+