conlang: bump version number

Comments in lib.rs outline my current thought processes

.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

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 = "0.0.4"
 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

@@ -563,106 +563,6 @@ 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

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
@@ -9,9 +9,13 @@
 //!   - [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;
 
 #[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
 pub enum Mutability {

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 +1,461 @@
+//! 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 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 {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        let Self { extents: _, kind } = self;
+        match kind {
+            ExprKind::Assign(v) => v.interpret(env),
+            ExprKind::Binary(v) => v.interpret(env),
+            ExprKind::Unary(v) => v.interpret(env),
+            ExprKind::Member(v) => v.interpret(env),
+            ExprKind::Call(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 { head, op, tail } = self;
+        // Resolve the head pattern
+        let head = match &head.kind {
+            ExprKind::Path(Path { parts, .. }) if parts.len() == 1 => {
+                match parts.last().expect("parts should not be empty") {
+                    PathPart::SuperKw => Err(Error::NotAssignable(head.extents.head))?,
+                    PathPart::SelfKw => todo!("Assignment to `self`"),
+                    PathPart::Ident(Identifier(s)) => s,
+                }
+            }
+            ExprKind::Member(_) => todo!("Member access assignment"),
+            ExprKind::Call(_) => todo!("Assignment to the result of a function call?"),
+            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(head.extents.head))?,
+        };
+        // 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 { head, tail } = self;
+        let mut head = head.interpret(env)?;
+        // Short-circuiting ops
+        for (op, tail) in tail {
+            match op {
+                BinaryKind::LogAnd => {
+                    if head.truthy()? {
+                        head = tail.interpret(env)?;
+                        continue;
+                    }
+                    return Ok(head); // Short circuiting
+                }
+                BinaryKind::LogOr => {
+                    if !head.truthy()? {
+                        head = tail.interpret(env)?;
+                        continue;
+                    }
+                    return Ok(head); // Short circuiting
+                }
+                BinaryKind::LogXor => {
+                    head = ConValue::Bool(head.truthy()? ^ tail.interpret(env)?.truthy()?);
+                    continue;
+                }
+                _ => {}
+            }
+            let tail = tail.interpret(env)?;
+            head = match op {
+                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!"),
+                _ => Ok(head),
+            }?;
+        }
+        Ok(head)
+    }
+}
+impl Interpret for Unary {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        let Unary { tail, ops } = self;
+        let mut operand = tail.interpret(env)?;
+
+        for op in ops.iter().rev() {
+            operand = match op {
+                UnaryKind::Deref => env.call("deref", &[operand])?,
+                UnaryKind::Neg => env.call("neg", &[operand])?,
+                UnaryKind::Not => env.call("not", &[operand])?,
+                UnaryKind::At => {
+                    println!("{operand}");
+                    operand
+                }
+                UnaryKind::Tilde => unimplemented!("Tilde operator"),
+            };
+        }
+        Ok(operand)
+    }
+}
+impl Interpret for Member {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        todo!("Interpret member accesses in {env}")
+    }
+}
+impl Interpret for Call {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        let Self { callee, args } = self;
+        // evaluate the callee
+        let mut callee = callee.interpret(env)?;
+        for args in args {
+            let ConValue::Tuple(args) = args.interpret(env)? else {
+                Err(Error::TypeError)?
+            };
+            callee = callee.call(env, &args)?;
+        }
+        Ok(callee)
+    }
+}
+impl Interpret for Index {
+    fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
+        let Self { head, indices } = self;
+        let mut head = head.interpret(env)?;
+        for indices in indices {
+            let Indices { exprs } = indices;
+            for index in exprs {
+                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 +1,615 @@
+//! 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;
+    use cl_structures::span::Loc;
+
+    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 at this [location](struct@Loc) can't be indexed
+        NotIndexable(Loc),
+        /// An array index went out of bounds
+        OobIndex(usize, usize),
+        /// An expression at this [location](struct@Loc)ation is not assignable
+        NotAssignable(Loc),
+        /// 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(location) => {
+                    write!(f, "{location} expression cannot be indexed")
+                }
+                Error::OobIndex(idx, len) => {
+                    write!(f, "Index out of bounds: index was {idx}. but len is {len}")
+                }
+                Error::NotAssignable(location) => {
+                    write!(f, "{location} 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_parser::Parser;
+use cl_lexer::Lexer;
 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::*;
 
@@ -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-xid = "0.2.4"

cl-lexer/src/lib.rs

@@ -1,11 +1,17 @@
 //! Converts a text file into tokens
-use crate::token::preamble::*;
+#![warn(clippy::all)]
+#![feature(decl_macro)]
+use cl_structures::span::Loc;
+use cl_token::*;
 use std::{
     iter::Peekable,
     str::{Chars, FromStr},
 };
 use unicode_xid::UnicodeXID;
 
+#[cfg(test)]
+mod tests;
+
 pub mod lexer_iter {
     //! Iterator over a [`Lexer`], returning [`LResult<Token>`]s
     use super::{
@@ -445,6 +451,12 @@ 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)

cl-lexer/src/tests.rs

@@ -0,0 +1,167 @@
+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),*) {
+        [$(Data::Identifier($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] }
+    }
+}

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(Type),
+    Expected {
+        want: Type,
+        got: Type,
+    },
+    /// 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}, but 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-parser/src/parser.rs

@@ -1,237 +1,13 @@
-//! Parses [tokens](super::token) into an [AST](super::ast)
-//!
-//! For the full grammar, see [grammar.ebnf][1]
-//!
-//! [1]: https://git.soft.fish/j/Conlang/src/branch/main/grammar.ebnf
-
-use self::error::{
+use super::*;
+use crate::error::{
     Error,
     ErrorKind::{self, *},
     PResult, Parsing,
 };
-use crate::{
-    ast::*,
-    common::*,
-    lexer::{error::Error as LexError, Lexer},
-    token::{
-        token_data::Data,
-        token_type::{Keyword, Type},
-        Token,
-    },
-};
-
-pub mod error {
-    use std::fmt::Display;
-
-    use super::*;
-    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(Type),
-        Expected {
-            want: Type,
-            got: Type,
-        },
-        /// No rules matched
-        Nothing,
-        /// Indicates unfinished code
-        Todo,
-    }
-    impl From<LexError> for ErrorKind {
-        fn from(value: LexError) -> Self {
-            use crate::lexer::error::Reason;
-            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
-                Todo => write!(f, "{loc} {reason} {while_parsing:?}"),
-                // lexical errors print their own higher-resolution loc info
-                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}, but 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)
-        }
-    }
-}
+use cl_ast::*;
+use cl_lexer::Lexer;
 
+/// Parses a sequence of [Tokens](Token) into an [AST](cl_ast)
 pub struct Parser<'t> {
     /// Lazy tokenizer
     lexer: Lexer<'t>,
@@ -849,7 +625,7 @@ impl<'t> Parser<'t> {
 }
 
 macro binary($($name:ident {$lower:ident, $op:ident})*) {
-    $(pub fn $name(&mut self) -> PResult<ExprKind> {
+$(pub fn $name(&mut self) -> PResult<ExprKind> {
     let head = self.expr_from(Self::$lower)?;
     let mut tail = vec![];
     loop {
@@ -863,7 +639,7 @@ macro binary($($name:ident {$lower:ident, $op:ident})*) {
         return Ok(head.kind);
     }
     Ok(Binary { head: head.into(), tail }.into())
-    })*
+})*
 }
 /// # Expression parsing
 impl<'t> Parser<'t> {
@@ -889,7 +665,11 @@ impl<'t> Parser<'t> {
     /// [Assign] = [Path] ([AssignKind] [Assign]) | [Compare](Binary)
     pub fn exprkind_assign(&mut self) -> PResult<ExprKind> {
         let head = self.expr_from(Self::exprkind_compare)?;
-        if !matches!(head.kind, ExprKind::Path(_)) {
+        // TODO: Formalize the concept of a "place expression"
+        if !matches!(
+            head.kind,
+            ExprKind::Path(_) | ExprKind::Call(_) | ExprKind::Member(_) | ExprKind::Index(_)
+        ) {
             return Ok(head.kind);
         }
         let Ok(op) = self.assign_op() else {
@@ -1163,7 +943,7 @@ impl<'t> Parser<'t> {
         pass: self.block()?.into(),
         fail: self.parse_else()?,
     })
-    }
+}
     /// [For]: `for` Pattern (TODO) `in` [Expr] [Block] [Else]?
     pub fn parse_for(&mut self) -> PResult<For> {
         self.match_kw(Keyword::For, Parsing::For)?;
@@ -1190,7 +970,7 @@ impl<'t> Parser<'t> {
 }
 
 macro operator($($name:ident ($returns:ident) {$($t:ident => $p:ident),*$(,)?};)*) {$(
-    pub fn $name (&mut self) -> PResult<$returns> {
+pub fn $name (&mut self) -> PResult<$returns> {
     const PARSING: Parsing = Parsing::$returns;
     let out = Ok(match self.peek_type(PARSING) {
         $(Ok(Type::$t) => $returns::$p,)*
@@ -1199,7 +979,7 @@ macro operator($($name:ident ($returns:ident) {$($t:ident => $p:ident),*$(,)?};)
     });
     self.consume_peeked();
     out
-    }
+}
 )*}
 
 /// ## Operator Kinds

cl-repl/Cargo.toml

@@ -10,5 +10,13 @@ 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-repl/examples/collect-identifiers.rs

@@ -1,7 +1,9 @@
 //! Collects identifiers into a list
 
+use cl_lexer::Lexer;
+use cl_parser::Parser;
 use cl_repl::repline::Repline;
-use conlang::{common::Loc, lexer::Lexer, parser::Parser};
+use cl_structures::span::Loc;
 use std::{
     collections::HashMap,
     error::Error,
@@ -124,7 +126,7 @@ use collectible::Collectible;
 pub mod collectible {
 
     use super::Collector;
-    use conlang::ast::*;
+    use cl_ast::*;
     pub trait Collectible<'code> {
         fn collect(&'code self, c: &mut Collector<'code>);
     }

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/src/bin/conlang.rs

@@ -0,0 +1,6 @@
+use cl_repl::cli::run;
+use std::error::Error;
+
+fn main() -> Result<(), Box<dyn Error>> {
+    run(argh::from_env())
+}

cl-repl/src/lib.rs

@@ -3,85 +3,93 @@
 //! # TODO
 //! - [ ] Readline-like line editing
 //! - [ ] Raw mode?
+#![warn(clippy::all)]
+
+pub mod ansi {
+    // ANSI color escape sequences
+    pub const ANSI_RED: &str = "\x1b[31m";
+    // 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 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 }
+        /// 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
+        #[argh(switch, short = 'r')]
+        pub no_repl: bool,
     }
-        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()
+
+    /// The CLI's operating mode
+    #[derive(Clone, Copy, Debug, Default, PartialEq, Eq, PartialOrd, Ord)]
+    pub enum Mode {
+        Tokenize,
+        Beautify,
+        #[default]
+        Interpret,
     }
-                    arg => {
-                        eprintln!("Unknown argument: {arg}");
-                        unknown = true;
+
+    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::{
+    use cl_interpret::{
         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_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 +144,6 @@ 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 +159,6 @@ 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 +170,102 @@ 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},
+        args::{Args, Mode},
+        program::{Parsable, Program},
+        repl::Repl,
+        tools::print_token,
     };
-    use std::{
-        convert::Infallible,
-        error::Error,
-        path::{Path, PathBuf},
-        str::FromStr,
+    use cl_interpret::{env::Environment, temp_type_impl::ConValue};
+    use cl_lexer::Lexer;
+    use cl_parser::Parser;
+    use std::{error::Error, path::Path};
+
+    /// Run the command line interface
+    pub fn run(args: Args) -> Result<(), Box<dyn Error>> {
+        let Args { file, include, mode, no_repl } = args;
+
+        let mut env = Environment::new();
+        for path in include {
+            load_file(&mut env, path)?;
+        }
+
+        if no_repl {
+            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);
 
-    // 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";
-
-    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 },
-            }
-        }
-    }
-    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())?)
+            match mode {
+                Mode::Tokenize => tokenize(code, file),
+                Mode::Beautify => beautify(code),
+                Mode::Interpret => interpret(code, &mut env),
+            }?;
+        } else {
+            if let Some(file) = file {
+                load_file(&mut env, file)?;
             }
+            Repl::with_env(mode, env).repl()
         }
         Ok(())
     }
-        fn no_repl(mode: Mode, path: Option<&Path>, code: &str) {
-            let program = Program::new(code);
-            match mode {
-                Mode::Tokenize => {
-                    for token in program.lex() {
-                        if let Some(path) = path {
-                            print!("{}:", path.display());
+
+    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)
+    }
+
+    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}"),
             }
         }
-                }
-                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}");
-            }
-        }
+        Ok(())
     }
 
-    /// The CLI's operating mode
-    #[derive(Clone, Copy, Debug, Default, PartialEq, Eq, PartialOrd, Ord)]
-    pub enum Mode {
-        Tokenize,
-        Beautify,
-        Resolve,
-        #[default]
-        Interpret,
+    fn beautify(code: Program<Parsable>) -> Result<(), Box<dyn Error>> {
+        code.parse()?.print();
+        Ok(())
     }
-    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 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() {
+            println!("-> {}", env.call("main", &[])?);
         }
+        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,
-            })
-        }
-    }
+}
+
+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 +273,8 @@ 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 +284,8 @@ pub mod cli {
                 prompt_begin: "cl>",
                 prompt_again: " ?>",
                 prompt_error: "! >",
+                prompt_succs: " =>",
                 env: Default::default(),
-                resolver: Default::default(),
                 mode: Default::default(),
             }
         }
@@ -371,9 +293,19 @@ 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_BRIGHT_GREEN}{prompt}{ANSI_RESET} {value}")
         }
         /// Resets the cursor to the start of the line, clears the terminal,
         /// and sets the output color
@@ -388,6 +320,10 @@ 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};
@@ -456,23 +392,26 @@ pub mod cli {
             );
         }
         fn command(&mut self, line: &str) -> bool {
-            match line.trim() {
-                "$pretty" => self.mode = Mode::Beautify,
-                "$tokens" => self.mode = Mode::Tokenize,
-                "$type" => self.mode = Mode::Resolve,
+            let Some(line) = line.trim().strip_prefix('$') 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(),
+                    "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 +424,20 @@ 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;
+    pub fn print_token(t: &Token) {
         println!(
             "{:02}:{:02}: {:#19} │{}│",
             t.line(),

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/lib.rs

@@ -0,0 +1,45 @@
+//! # 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)]
+
+pub mod span {
+    //! - [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)]
+
+    /// Stores the start and end [locations](struct@Loc) within the token stream
+    #[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+    pub struct Span {
+        pub head: Loc,
+        pub tail: Loc,
+    }
+    pub fn Span(head: Loc, tail: Loc) -> Span {
+        Span { head, tail }
+    }
+
+    /// Stores a read-only (line, column) location in a token stream
+    #[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+    pub struct Loc {
+        line: u32,
+        col: u32,
+    }
+    pub fn Loc(line: u32, col: u32) -> Loc {
+        Loc { line, col }
+    }
+    impl Loc {
+        pub fn line(self) -> u32 {
+            self.line
+        }
+        pub fn col(self) -> u32 {
+            self.col
+        }
+    }
+
+    impl std::fmt::Display for Loc {
+        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+            let Loc { line, col } = self;
+            write!(f, "{line}:{col}:")
+        }
+    }
+}

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 [Type], some [Data], 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::Data;
+pub use token_type::{Keyword, Type};

cl-token/src/token.rs

@@ -1,20 +1,5 @@
-//! # 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;
+//! A [Token] contains a single unit of lexical information, and an optional bit of [Data]
+use super::{Data, Type};
 
 /// Contains a single unit of lexical information,
 /// and an optional bit of [Data]

cl-typeck/Cargo.toml

@@ -0,0 +1,11 @@
+[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-typeck/src/lib.rs

@@ -0,0 +1,210 @@
+//! # The Conlang Type Checker
+//!
+//! As a statically typed language, Conlang requires a robust type checker to enforce correctness.
+
+#![warn(clippy::all)]
+#![allow(unused)]
+use std::{cell::RefCell, collections::HashMap, rc::Rc};
+
+use cl_ast::*;
+
+pub mod intern {
+    //! Trivially-copyable, easily comparable typed indices for type system constructs
+
+    /// Creates newtype indices over [`usize`] for use elsewhere in the type checker
+    macro_rules! def_id {($($(#[$meta:meta])* $name:ident),*$(,)?) => {$(
+        $(#[$meta])*
+        #[repr(transparent)]
+        #[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+        pub struct $name(usize);
+
+        impl $name {
+            #[doc = concat!("Constructs a [`", stringify!($name), "`] from a [`usize`] without checking bounds.")]
+            /// # Safety
+            /// The provided value should be within the bounds of its associated container
+            pub unsafe fn from_raw_unchecked(value: usize) -> Self {
+                Self(value)
+            }
+            /// Gets the index of the type by-value
+            pub fn value(&self) -> usize {
+                self.0
+            }
+        }
+
+        impl From< $name > for usize {
+            fn from(value: $name) -> Self {
+                value.0
+            }
+        }
+    )*}}
+
+    // define the index types
+    def_id! {
+        /// Uniquely represents a Type
+        TypeID,
+        /// Uniquely represents a Value
+        ValueID,
+    }
+}
+
+pub mod typedef {
+    //! Representations of type definitions
+    // use std::collections::HashMap;
+
+    use crate::intern::TypeID;
+    use cl_ast::{Item, Visibility};
+
+    /// The definition of a type
+    #[derive(Clone, Debug, PartialEq, Eq)]
+    pub struct TypeDef {
+        name: String,
+        kind: Option<TypeKind>,
+        definition: Item,
+    }
+
+    #[derive(Clone, Debug, PartialEq, Eq)]
+    pub enum TypeKind {
+        /// A primitive type, built-in to the compiler
+        Intrinsic,
+        /// A user-defined structural product type
+        Struct(Vec<(String, Visibility, TypeID)>),
+        /// A user-defined union-like enum type
+        Enum(Vec<(String, TypeID)>),
+        /// A type alias
+        Alias(TypeID),
+        /// The unit type
+        Empty,
+        /// The Self type
+        SelfTy,
+        // TODO: other types
+    }
+}
+
+pub mod valdef {
+    //! Representations of value definitions
+
+    use crate::intern::{TypeID, ValueID};
+    use cl_ast::Block;
+
+    #[derive(Clone, Debug, PartialEq, Eq)]
+    pub struct ValueDef {
+        name: String,
+        kind: Option<ValueKind>,
+    }
+
+    #[derive(Clone, Debug, PartialEq, Eq)]
+    pub enum ValueKind {
+        Const(),
+        Static(),
+        Fn {
+            args: Vec<TypeID>,
+            rety: TypeID,
+            body: Block,
+        },
+    }
+}
+
+pub mod typeinfo {
+    //! Stores typeck-time type inference info
+
+    use crate::intern::TypeID;
+
+    /// 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,
+        /// Types can be [Generic](TKind::Generic) or [Concrete](TKind::Concrete)
+        kind: TKind,
+    }
+
+    /// Types can be [Generic](TKind::Generic) or [Concrete](TKind::Concrete)
+    pub enum TKind {
+        /// A Concrete type has an associated [TypeDef](super::typedef::TypeDef)
+        Concrete(TypeID),
+        /// A Generic type is a *locally unique* comparable value,
+        /// valid only until the end of its inference context
+        Generic(usize),
+    }
+}
+
+pub mod type_context {
+    //! A type context stores a map from names to TypeIDs
+
+    use std::collections::HashMap;
+
+    use crate::intern::TypeID;
+
+    pub struct TypeCtx {
+        parent: Option<Box<TypeCtx>>,
+        concrete: HashMap<String, TypeID>,
+    }
+}
+
+/*
+/// 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>> {
+
+}
+
+*/
+
+/*
+    Potential solution:
+    Store reference to type field of each type expression in the AST
+*/

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/common.rs

@@ -1,46 +0,0 @@
-//! # 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)]
-pub struct Span {
-    pub head: Loc,
-    pub tail: Loc,
-}
-pub fn Span(head: Loc, tail: Loc) -> Span {
-    Span { head, tail }
-}
-
-/// Stores a read-only (line, column) location in a token stream
-#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct Loc {
-    line: u32,
-    col: u32,
-}
-pub fn Loc(line: u32, col: u32) -> Loc {
-    Loc { line, col }
-}
-impl Loc {
-    pub fn line(self) -> u32 {
-        self.line
-    }
-    pub fn col(self) -> u32 {
-        self.col
-    }
-}
-
-impl std::fmt::Display for Loc {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        let Loc { line, col } = self;
-        write!(f, "{line}:{col}:")
-    }
-}
-
-impl<'t> From<&Lexer<'t>> for Loc {
-    fn from(value: &Lexer<'t>) -> Self {
-        Loc(value.line(), value.col())
-    }
-}

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
-}

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;
+
+