chore(users): grfn -> aspen r/7511

Change-Id: I6c6847fac56f0a9a1a2209792e00a3aec5e672b9
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10809
Autosubmit: aspen <root@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
Reviewed-by: lukegb <lukegb@tvl.fyi>

1 files changed, 0 insertions, 808 deletions

diff --git a/users/grfn/achilles/src/tc/mod.rs b/users/grfn/achilles/src/tc/mod.rs
deleted file mode 100644
index 5825bab1fbe9..000000000000
--- a/users/grfn/achilles/src/tc/mod.rs
+++ /dev/null
@@ -1,808 +0,0 @@
-use bimap::BiMap;
-use derive_more::From;
-use itertools::Itertools;
-use std::cell::RefCell;
-use std::collections::HashMap;
-use std::convert::{TryFrom, TryInto};
-use std::fmt::{self, Display};
-use std::{mem, result};
-use thiserror::Error;
-
-use crate::ast::{self, hir, Arg, BinaryOperator, Ident, Literal, Pattern};
-use crate::common::env::Env;
-use crate::common::{Namer, NamerOf};
-
-#[derive(Debug, Error)]
-pub enum Error {
-    #[error("Undefined variable {0}")]
-    UndefinedVariable(Ident<'static>),
-
-    #[error("Mismatched types: expected {expected}, but got {actual}")]
-    TypeMismatch { expected: Type, actual: Type },
-
-    #[error("Mismatched types, expected numeric type, but got {0}")]
-    NonNumeric(Type),
-
-    #[error("Ambiguous type {0}")]
-    AmbiguousType(TyVar),
-}
-
-pub type Result<T> = result::Result<T, Error>;
-
-#[derive(Debug, PartialEq, Eq, Clone, Copy, Hash)]
-pub struct TyVar(u64);
-
-impl Display for TyVar {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "t{}", self.0)
-    }
-}
-
-#[derive(Debug, PartialEq, Eq, Clone, Hash)]
-pub struct NullaryType(String);
-
-impl Display for NullaryType {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.write_str(&self.0)
-    }
-}
-
-#[derive(Debug, PartialEq, Eq, Clone, Copy)]
-pub enum PrimType {
-    Int,
-    Float,
-    Bool,
-    CString,
-}
-
-impl<'a> From<PrimType> for ast::Type<'a> {
-    fn from(pr: PrimType) -> Self {
-        match pr {
-            PrimType::Int => ast::Type::Int,
-            PrimType::Float => ast::Type::Float,
-            PrimType::Bool => ast::Type::Bool,
-            PrimType::CString => ast::Type::CString,
-        }
-    }
-}
-
-impl Display for PrimType {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            PrimType::Int => f.write_str("int"),
-            PrimType::Float => f.write_str("float"),
-            PrimType::Bool => f.write_str("bool"),
-            PrimType::CString => f.write_str("cstring"),
-        }
-    }
-}
-
-#[derive(Debug, PartialEq, Eq, Clone, From)]
-pub enum Type {
-    #[from(ignore)]
-    Univ(TyVar),
-    #[from(ignore)]
-    Exist(TyVar),
-    Nullary(NullaryType),
-    Prim(PrimType),
-    Tuple(Vec<Type>),
-    Unit,
-    Fun {
-        args: Vec<Type>,
-        ret: Box<Type>,
-    },
-}
-
-impl<'a> TryFrom<Type> for ast::Type<'a> {
-    type Error = Type;
-
-    fn try_from(value: Type) -> result::Result<Self, Self::Error> {
-        match value {
-            Type::Unit => Ok(ast::Type::Unit),
-            Type::Univ(_) => todo!(),
-            Type::Exist(_) => Err(value),
-            Type::Nullary(_) => todo!(),
-            Type::Prim(p) => Ok(p.into()),
-            Type::Tuple(members) => Ok(ast::Type::Tuple(
-                members.into_iter().map(|ty| ty.try_into()).try_collect()?,
-            )),
-            Type::Fun { ref args, ref ret } => Ok(ast::Type::Function(ast::FunctionType {
-                args: args
-                    .clone()
-                    .into_iter()
-                    .map(Self::try_from)
-                    .try_collect()
-                    .map_err(|_| value.clone())?,
-                ret: Box::new((*ret.clone()).try_into().map_err(|_| value.clone())?),
-            })),
-        }
-    }
-}
-
-const INT: Type = Type::Prim(PrimType::Int);
-const FLOAT: Type = Type::Prim(PrimType::Float);
-const BOOL: Type = Type::Prim(PrimType::Bool);
-const CSTRING: Type = Type::Prim(PrimType::CString);
-
-impl Display for Type {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            Type::Nullary(nt) => nt.fmt(f),
-            Type::Prim(p) => p.fmt(f),
-            Type::Univ(TyVar(n)) => write!(f, "∀{}", n),
-            Type::Exist(TyVar(n)) => write!(f, "∃{}", n),
-            Type::Fun { args, ret } => write!(f, "fn {} -> {}", args.iter().join(", "), ret),
-            Type::Tuple(members) => write!(f, "({})", members.iter().join(", ")),
-            Type::Unit => write!(f, "()"),
-        }
-    }
-}
-
-struct Typechecker<'ast> {
-    ty_var_namer: NamerOf<TyVar>,
-    ctx: HashMap<TyVar, Type>,
-    env: Env<Ident<'ast>, Type>,
-
-    /// AST type var -> type
-    instantiations: Env<Ident<'ast>, Type>,
-
-    /// AST type-var -> universal TyVar
-    type_vars: RefCell<(BiMap<Ident<'ast>, TyVar>, NamerOf<Ident<'static>>)>,
-}
-
-impl<'ast> Typechecker<'ast> {
-    fn new() -> Self {
-        Self {
-            ty_var_namer: Namer::new(TyVar).boxed(),
-            type_vars: RefCell::new((
-                Default::default(),
-                Namer::alphabetic().map(|n| Ident::try_from(n).unwrap()),
-            )),
-            ctx: Default::default(),
-            env: Default::default(),
-            instantiations: Default::default(),
-        }
-    }
-
-    fn bind_pattern(
-        &mut self,
-        pat: Pattern<'ast>,
-        type_: Type,
-    ) -> Result<hir::Pattern<'ast, Type>> {
-        match pat {
-            Pattern::Id(ident) => {
-                self.env.set(ident.clone(), type_.clone());
-                Ok(hir::Pattern::Id(ident, type_))
-            }
-            Pattern::Tuple(members) => {
-                let mut tys = Vec::with_capacity(members.len());
-                let mut hir_members = Vec::with_capacity(members.len());
-                for pat in members {
-                    let ty = self.fresh_ex();
-                    hir_members.push(self.bind_pattern(pat, ty.clone())?);
-                    tys.push(ty);
-                }
-                let tuple_type = Type::Tuple(tys);
-                self.unify(&tuple_type, &type_)?;
-                Ok(hir::Pattern::Tuple(hir_members))
-            }
-        }
-    }
-
-    pub(crate) fn tc_expr(&mut self, expr: ast::Expr<'ast>) -> Result<hir::Expr<'ast, Type>> {
-        match expr {
-            ast::Expr::Ident(ident) => {
-                let type_ = self
-                    .env
-                    .resolve(&ident)
-                    .ok_or_else(|| Error::UndefinedVariable(ident.to_owned()))?
-                    .clone();
-                Ok(hir::Expr::Ident(ident, type_))
-            }
-            ast::Expr::Literal(lit) => {
-                let type_ = match lit {
-                    Literal::Int(_) => Type::Prim(PrimType::Int),
-                    Literal::Bool(_) => Type::Prim(PrimType::Bool),
-                    Literal::String(_) => Type::Prim(PrimType::CString),
-                    Literal::Unit => Type::Unit,
-                };
-                Ok(hir::Expr::Literal(lit.to_owned(), type_))
-            }
-            ast::Expr::Tuple(members) => {
-                let members = members
-                    .into_iter()
-                    .map(|expr| self.tc_expr(expr))
-                    .collect::<Result<Vec<_>>>()?;
-                let type_ = Type::Tuple(members.iter().map(|expr| expr.type_().clone()).collect());
-                Ok(hir::Expr::Tuple(members, type_))
-            }
-            ast::Expr::UnaryOp { op, rhs } => todo!(),
-            ast::Expr::BinaryOp { lhs, op, rhs } => {
-                let lhs = self.tc_expr(*lhs)?;
-                let rhs = self.tc_expr(*rhs)?;
-                let type_ = match op {
-                    BinaryOperator::Equ | BinaryOperator::Neq => {
-                        self.unify(lhs.type_(), rhs.type_())?;
-                        Type::Prim(PrimType::Bool)
-                    }
-                    BinaryOperator::Add | BinaryOperator::Sub | BinaryOperator::Mul => {
-                        let ty = self.unify(lhs.type_(), rhs.type_())?;
-                        // if !matches!(ty, Type::Int | Type::Float) {
-                        //     return Err(Error::NonNumeric(ty));
-                        // }
-                        ty
-                    }
-                    BinaryOperator::Div => todo!(),
-                    BinaryOperator::Pow => todo!(),
-                };
-                Ok(hir::Expr::BinaryOp {
-                    lhs: Box::new(lhs),
-                    op,
-                    rhs: Box::new(rhs),
-                    type_,
-                })
-            }
-            ast::Expr::Let { bindings, body } => {
-                self.env.push();
-                let bindings = bindings
-                    .into_iter()
-                    .map(
-                        |ast::Binding { pat, type_, body }| -> Result<hir::Binding<Type>> {
-                            let body = self.tc_expr(body)?;
-                            if let Some(type_) = type_ {
-                                let type_ = self.type_from_ast_type(type_);
-                                self.unify(body.type_(), &type_)?;
-                            }
-                            let pat = self.bind_pattern(pat, body.type_().clone())?;
-                            Ok(hir::Binding { pat, body })
-                        },
-                    )
-                    .collect::<Result<Vec<hir::Binding<Type>>>>()?;
-                let body = self.tc_expr(*body)?;
-                self.env.pop();
-                Ok(hir::Expr::Let {
-                    bindings,
-                    type_: body.type_().clone(),
-                    body: Box::new(body),
-                })
-            }
-            ast::Expr::If {
-                condition,
-                then,
-                else_,
-            } => {
-                let condition = self.tc_expr(*condition)?;
-                self.unify(&Type::Prim(PrimType::Bool), condition.type_())?;
-                let then = self.tc_expr(*then)?;
-                let else_ = self.tc_expr(*else_)?;
-                let type_ = self.unify(then.type_(), else_.type_())?;
-                Ok(hir::Expr::If {
-                    condition: Box::new(condition),
-                    then: Box::new(then),
-                    else_: Box::new(else_),
-                    type_,
-                })
-            }
-            ast::Expr::Fun(f) => {
-                let ast::Fun { args, body } = *f;
-                self.env.push();
-                let args: Vec<_> = args
-                    .into_iter()
-                    .map(|Arg { ident, type_ }| {
-                        let ty = match type_ {
-                            Some(t) => self.type_from_ast_type(t),
-                            None => self.fresh_ex(),
-                        };
-                        self.env.set(ident.clone(), ty.clone());
-                        (ident, ty)
-                    })
-                    .collect();
-                let body = self.tc_expr(body)?;
-                self.env.pop();
-                Ok(hir::Expr::Fun {
-                    type_: Type::Fun {
-                        args: args.iter().map(|(_, ty)| ty.clone()).collect(),
-                        ret: Box::new(body.type_().clone()),
-                    },
-                    type_args: vec![], // TODO fill in once we do let generalization
-                    args,
-                    body: Box::new(body),
-                })
-            }
-            ast::Expr::Call { fun, args } => {
-                let ret_ty = self.fresh_ex();
-                let arg_tys = args.iter().map(|_| self.fresh_ex()).collect::<Vec<_>>();
-                let ft = Type::Fun {
-                    args: arg_tys.clone(),
-                    ret: Box::new(ret_ty.clone()),
-                };
-                let fun = self.tc_expr(*fun)?;
-                self.instantiations.push();
-                self.unify(&ft, fun.type_())?;
-                let args = args
-                    .into_iter()
-                    .zip(arg_tys)
-                    .map(|(arg, ty)| {
-                        let arg = self.tc_expr(arg)?;
-                        self.unify(&ty, arg.type_())?;
-                        Ok(arg)
-                    })
-                    .try_collect()?;
-                let type_args = self.commit_instantiations();
-                Ok(hir::Expr::Call {
-                    fun: Box::new(fun),
-                    type_args,
-                    args,
-                    type_: ret_ty,
-                })
-            }
-            ast::Expr::Ascription { expr, type_ } => {
-                let expr = self.tc_expr(*expr)?;
-                let type_ = self.type_from_ast_type(type_);
-                self.unify(expr.type_(), &type_)?;
-                Ok(expr)
-            }
-        }
-    }
-
-    pub(crate) fn tc_decl(
-        &mut self,
-        decl: ast::Decl<'ast>,
-    ) -> Result<Option<hir::Decl<'ast, Type>>> {
-        match decl {
-            ast::Decl::Fun { name, body } => {
-                let mut expr = ast::Expr::Fun(Box::new(body));
-                if let Some(type_) = self.env.resolve(&name) {
-                    expr = ast::Expr::Ascription {
-                        expr: Box::new(expr),
-                        type_: self.finalize_type(type_.clone())?,
-                    };
-                }
-
-                self.env.push();
-                let body = self.tc_expr(expr)?;
-                let type_ = body.type_().clone();
-                self.env.set(name.clone(), type_);
-                self.env.pop();
-                match body {
-                    hir::Expr::Fun {
-                        type_args,
-                        args,
-                        body,
-                        type_,
-                    } => Ok(Some(hir::Decl::Fun {
-                        name,
-                        type_args,
-                        args,
-                        body,
-                        type_,
-                    })),
-                    _ => unreachable!(),
-                }
-            }
-            ast::Decl::Ascription { name, type_ } => {
-                let type_ = self.type_from_ast_type(type_);
-                self.env.set(name.clone(), type_);
-                Ok(None)
-            }
-            ast::Decl::Extern { name, type_ } => {
-                let type_ = self.type_from_ast_type(ast::Type::Function(type_));
-                self.env.set(name.clone(), type_.clone());
-                let (arg_types, ret_type) = match type_ {
-                    Type::Fun { args, ret } => (args, *ret),
-                    _ => unreachable!(),
-                };
-                Ok(Some(hir::Decl::Extern {
-                    name,
-                    arg_types,
-                    ret_type,
-                }))
-            }
-        }
-    }
-
-    fn fresh_tv(&mut self) -> TyVar {
-        self.ty_var_namer.make_name()
-    }
-
-    fn fresh_ex(&mut self) -> Type {
-        Type::Exist(self.fresh_tv())
-    }
-
-    fn fresh_univ(&mut self) -> Type {
-        Type::Univ(self.fresh_tv())
-    }
-
-    fn unify(&mut self, ty1: &Type, ty2: &Type) -> Result<Type> {
-        match (ty1, ty2) {
-            (Type::Unit, Type::Unit) => Ok(Type::Unit),
-            (Type::Exist(tv), ty) | (ty, Type::Exist(tv)) => match self.resolve_tv(*tv)? {
-                Some(existing_ty) if self.types_match(ty, &existing_ty) => Ok(ty.clone()),
-                Some(var @ ast::Type::Var(_)) => {
-                    let var = self.type_from_ast_type(var);
-                    self.unify(&var, ty)
-                }
-                Some(existing_ty) => match ty {
-                    Type::Exist(_) => {
-                        let rhs = self.type_from_ast_type(existing_ty);
-                        self.unify(ty, &rhs)
-                    }
-                    _ => Err(Error::TypeMismatch {
-                        expected: ty.clone(),
-                        actual: self.type_from_ast_type(existing_ty),
-                    }),
-                },
-                None => match self.ctx.insert(*tv, ty.clone()) {
-                    Some(existing) => self.unify(&existing, ty),
-                    None => Ok(ty.clone()),
-                },
-            },
-            (Type::Univ(u1), Type::Univ(u2)) if u1 == u2 => Ok(ty2.clone()),
-            (Type::Univ(u), ty) | (ty, Type::Univ(u)) => {
-                let ident = self.name_univ(*u);
-                match self.instantiations.resolve(&ident) {
-                    Some(existing_ty) if ty == existing_ty => Ok(ty.clone()),
-                    Some(existing_ty) => Err(Error::TypeMismatch {
-                        expected: ty.clone(),
-                        actual: existing_ty.clone(),
-                    }),
-                    None => {
-                        self.instantiations.set(ident, ty.clone());
-                        Ok(ty.clone())
-                    }
-                }
-            }
-            (Type::Prim(p1), Type::Prim(p2)) if p1 == p2 => Ok(ty2.clone()),
-            (Type::Tuple(t1), Type::Tuple(t2)) if t1.len() == t2.len() => {
-                let ts = t1
-                    .iter()
-                    .zip(t2.iter())
-                    .map(|(t1, t2)| self.unify(t1, t2))
-                    .try_collect()?;
-                Ok(Type::Tuple(ts))
-            }
-            (
-                Type::Fun {
-                    args: args1,
-                    ret: ret1,
-                },
-                Type::Fun {
-                    args: args2,
-                    ret: ret2,
-                },
-            ) => {
-                let args = args1
-                    .iter()
-                    .zip(args2)
-                    .map(|(t1, t2)| self.unify(t1, t2))
-                    .try_collect()?;
-                let ret = self.unify(ret1, ret2)?;
-                Ok(Type::Fun {
-                    args,
-                    ret: Box::new(ret),
-                })
-            }
-            (Type::Nullary(_), _) | (_, Type::Nullary(_)) => todo!(),
-            _ => Err(Error::TypeMismatch {
-                expected: ty1.clone(),
-                actual: ty2.clone(),
-            }),
-        }
-    }
-
-    fn finalize_expr(
-        &self,
-        expr: hir::Expr<'ast, Type>,
-    ) -> Result<hir::Expr<'ast, ast::Type<'ast>>> {
-        expr.traverse_type(|ty| self.finalize_type(ty))
-    }
-
-    fn finalize_decl(
-        &mut self,
-        decl: hir::Decl<'ast, Type>,
-    ) -> Result<hir::Decl<'ast, ast::Type<'ast>>> {
-        let res = decl.traverse_type(|ty| self.finalize_type(ty))?;
-        if let Some(type_) = res.type_() {
-            let ty = self.type_from_ast_type(type_.clone());
-            self.env.set(res.name().clone(), ty);
-        }
-        Ok(res)
-    }
-
-    fn finalize_type(&self, ty: Type) -> Result<ast::Type<'static>> {
-        let ret = match ty {
-            Type::Exist(tv) => self.resolve_tv(tv)?.ok_or(Error::AmbiguousType(tv)),
-            Type::Univ(tv) => Ok(ast::Type::Var(self.name_univ(tv))),
-            Type::Unit => Ok(ast::Type::Unit),
-            Type::Nullary(_) => todo!(),
-            Type::Prim(pr) => Ok(pr.into()),
-            Type::Tuple(members) => Ok(ast::Type::Tuple(
-                members
-                    .into_iter()
-                    .map(|ty| self.finalize_type(ty))
-                    .try_collect()?,
-            )),
-            Type::Fun { args, ret } => Ok(ast::Type::Function(ast::FunctionType {
-                args: args
-                    .into_iter()
-                    .map(|ty| self.finalize_type(ty))
-                    .try_collect()?,
-                ret: Box::new(self.finalize_type(*ret)?),
-            })),
-        };
-        ret
-    }
-
-    fn resolve_tv(&self, tv: TyVar) -> Result<Option<ast::Type<'static>>> {
-        let mut res = &Type::Exist(tv);
-        Ok(loop {
-            match res {
-                Type::Exist(tv) => {
-                    res = match self.ctx.get(tv) {
-                        Some(r) => r,
-                        None => return Ok(None),
-                    };
-                }
-                Type::Univ(tv) => {
-                    let ident = self.name_univ(*tv);
-                    if let Some(r) = self.instantiations.resolve(&ident) {
-                        res = r;
-                    } else {
-                        break Some(ast::Type::Var(ident));
-                    }
-                }
-                Type::Nullary(_) => todo!(),
-                Type::Prim(pr) => break Some((*pr).into()),
-                Type::Unit => break Some(ast::Type::Unit),
-                Type::Fun { args, ret } => todo!(),
-                Type::Tuple(_) => break Some(self.finalize_type(res.clone())?),
-            }
-        })
-    }
-
-    fn type_from_ast_type(&mut self, ast_type: ast::Type<'ast>) -> Type {
-        match ast_type {
-            ast::Type::Unit => Type::Unit,
-            ast::Type::Int => INT,
-            ast::Type::Float => FLOAT,
-            ast::Type::Bool => BOOL,
-            ast::Type::CString => CSTRING,
-            ast::Type::Tuple(members) => Type::Tuple(
-                members
-                    .into_iter()
-                    .map(|ty| self.type_from_ast_type(ty))
-                    .collect(),
-            ),
-            ast::Type::Function(ast::FunctionType { args, ret }) => Type::Fun {
-                args: args
-                    .into_iter()
-                    .map(|t| self.type_from_ast_type(t))
-                    .collect(),
-                ret: Box::new(self.type_from_ast_type(*ret)),
-            },
-            ast::Type::Var(id) => Type::Univ({
-                let opt_tv = { self.type_vars.borrow_mut().0.get_by_left(&id).copied() };
-                opt_tv.unwrap_or_else(|| {
-                    let tv = self.fresh_tv();
-                    self.type_vars
-                        .borrow_mut()
-                        .0
-                        .insert_no_overwrite(id, tv)
-                        .unwrap();
-                    tv
-                })
-            }),
-        }
-    }
-
-    fn name_univ(&self, tv: TyVar) -> Ident<'static> {
-        let mut vars = self.type_vars.borrow_mut();
-        vars.0
-            .get_by_right(&tv)
-            .map(Ident::to_owned)
-            .unwrap_or_else(|| {
-                let name = loop {
-                    let name = vars.1.make_name();
-                    if !vars.0.contains_left(&name) {
-                        break name;
-                    }
-                };
-                vars.0.insert_no_overwrite(name.clone(), tv).unwrap();
-                name
-            })
-    }
-
-    fn commit_instantiations(&mut self) -> HashMap<Ident<'ast>, Type> {
-        let mut res = HashMap::new();
-        let mut ctx = mem::take(&mut self.ctx);
-        for (_, v) in ctx.iter_mut() {
-            if let Type::Univ(tv) = v {
-                let tv_name = self.name_univ(*tv);
-                if let Some(concrete) = self.instantiations.resolve(&tv_name) {
-                    res.insert(tv_name, concrete.clone());
-                    *v = concrete.clone();
-                }
-            }
-        }
-        self.ctx = ctx;
-        self.instantiations.pop();
-        res
-    }
-
-    fn types_match(&self, type_: &Type, ast_type: &ast::Type<'ast>) -> bool {
-        match (type_, ast_type) {
-            (Type::Univ(u), ast::Type::Var(v)) => {
-                Some(u) == self.type_vars.borrow().0.get_by_left(v)
-            }
-            (Type::Univ(_), _) => false,
-            (Type::Exist(_), _) => false,
-            (Type::Unit, ast::Type::Unit) => true,
-            (Type::Unit, _) => false,
-            (Type::Nullary(_), _) => todo!(),
-            (Type::Prim(pr), ty) => ast::Type::from(*pr) == *ty,
-            (Type::Tuple(members), ast::Type::Tuple(members2)) => members
-                .iter()
-                .zip(members2.iter())
-                .all(|(t1, t2)| self.types_match(t1, t2)),
-            (Type::Tuple(members), _) => false,
-            (Type::Fun { args, ret }, ast::Type::Function(ft)) => {
-                args.len() == ft.args.len()
-                    && args
-                        .iter()
-                        .zip(&ft.args)
-                        .all(|(a1, a2)| self.types_match(a1, &a2))
-                    && self.types_match(&*ret, &*ft.ret)
-            }
-            (Type::Fun { .. }, _) => false,
-        }
-    }
-}
-
-pub fn typecheck_expr(expr: ast::Expr) -> Result<hir::Expr<ast::Type>> {
-    let mut typechecker = Typechecker::new();
-    let typechecked = typechecker.tc_expr(expr)?;
-    typechecker.finalize_expr(typechecked)
-}
-
-pub fn typecheck_toplevel(decls: Vec<ast::Decl>) -> Result<Vec<hir::Decl<ast::Type>>> {
-    let mut typechecker = Typechecker::new();
-    let mut res = Vec::with_capacity(decls.len());
-    for decl in decls {
-        if let Some(hir_decl) = typechecker.tc_decl(decl)? {
-            let hir_decl = typechecker.finalize_decl(hir_decl)?;
-            res.push(hir_decl);
-        }
-        typechecker.ctx.clear();
-    }
-    Ok(res)
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    macro_rules! assert_type {
-        ($expr: expr, $type: expr) => {
-            use crate::parser::{expr, type_};
-            let parsed_expr = test_parse!(expr, $expr);
-            let parsed_type = test_parse!(type_, $type);
-            let res = typecheck_expr(parsed_expr).unwrap_or_else(|e| panic!("{}", e));
-            assert!(
-                res.type_().alpha_equiv(&parsed_type),
-                "{} inferred type {}, but expected {}",
-                $expr,
-                res.type_(),
-                $type
-            );
-        };
-
-        (toplevel($program: expr), $($decl: ident => $type: expr),+ $(,)?) => {{
-            use crate::parser::{toplevel, type_};
-            let program = test_parse!(toplevel, $program);
-            let res = typecheck_toplevel(program).unwrap_or_else(|e| panic!("{}", e));
-            $(
-            let parsed_type = test_parse!(type_, $type);
-            let ident = Ident::try_from(::std::stringify!($decl)).unwrap();
-            let decl = res.iter().find(|decl| {
-                matches!(decl, crate::ast::hir::Decl::Fun { name, .. } if name == &ident)
-            }).unwrap_or_else(|| panic!("Could not find declaration for {}", ident));
-            assert!(
-                decl.type_().unwrap().alpha_equiv(&parsed_type),
-                "inferred type {} for {}, but expected {}",
-                decl.type_().unwrap(),
-                ident,
-                $type
-            );
-            )+
-        }};
-    }
-
-    macro_rules! assert_type_error {
-        ($expr: expr) => {
-            use crate::parser::expr;
-            let parsed_expr = test_parse!(expr, $expr);
-            let res = typecheck_expr(parsed_expr);
-            assert!(
-                res.is_err(),
-                "Expected type error, but got type: {}",
-                res.unwrap().type_()
-            );
-        };
-    }
-
-    #[test]
-    fn literal_int() {
-        assert_type!("1", "int");
-    }
-
-    #[test]
-    fn conditional() {
-        assert_type!("if 1 == 2 then 3 else 4", "int");
-    }
-
-    #[test]
-    #[ignore]
-    fn add_bools() {
-        assert_type_error!("true + false");
-    }
-
-    #[test]
-    fn call_generic_function() {
-        assert_type!("(fn x = x) 1", "int");
-    }
-
-    #[test]
-    fn call_let_bound_generic() {
-        assert_type!("let id = fn x = x in id 1", "int");
-    }
-
-    #[test]
-    fn universal_ascripted_let() {
-        assert_type!("let id: fn a -> a = fn x = x in id 1", "int");
-    }
-
-    #[test]
-    fn call_generic_function_toplevel() {
-        assert_type!(
-            toplevel(
-                "ty id : fn a -> a
-                 fn id x = x
-
-                 fn main = id 0"
-            ),
-            main => "fn -> int",
-            id => "fn a -> a",
-        );
-    }
-
-    #[test]
-    #[ignore]
-    fn let_generalization() {
-        assert_type!("let id = fn x = x in if id true then id 1 else 2", "int");
-    }
-
-    #[test]
-    fn concrete_function() {
-        assert_type!("fn x = x + 1", "fn int -> int");
-    }
-
-    #[test]
-    fn arg_ascriptions() {
-        assert_type!("fn (x: int) = x", "fn int -> int");
-    }
-
-    #[test]
-    fn call_concrete_function() {
-        assert_type!("(fn x = x + 1) 2", "int");
-    }
-
-    #[test]
-    fn conditional_non_bool() {
-        assert_type_error!("if 3 then true else false");
-    }
-
-    #[test]
-    fn let_int() {
-        assert_type!("let x = 1 in x", "int");
-    }
-}