Thread cx through typecheck

2 files changed, 24 insertions, 11 deletions

diff --git a/dhall/src/semantics/tck/env.rs b/dhall/src/semantics/tck/env.rs
index 1fa66f0..fc0ce9f 100644
--- a/dhall/src/semantics/tck/env.rs
+++ b/dhall/src/semantics/tck/env.rs
@@ -1,5 +1,6 @@
 use crate::semantics::{AlphaVar, NameEnv, Nir, NzEnv, NzVar, Type, ValEnv};
 use crate::syntax::Label;
+use crate::Ctxt;
 
 /// Environment for indexing variables.
 #[derive(Debug, Clone, Copy, Default)]
@@ -9,7 +10,8 @@ pub struct VarEnv {
 
 /// Environment for typing expressions.
 #[derive(Debug, Clone)]
-pub struct TyEnv {
+pub struct TyEnv<'cx> {
+    cx: Ctxt<'cx>,
     names: NameEnv,
     items: ValEnv<Type>,
 }
@@ -38,13 +40,17 @@ impl VarEnv {
     }
 }
 
-impl TyEnv {
-    pub fn new() -> Self {
+impl<'cx> TyEnv<'cx> {
+    pub fn new(cx: Ctxt<'cx>) -> Self {
         TyEnv {
+            cx,
             names: NameEnv::new(),
             items: ValEnv::new(),
         }
     }
+    pub fn cx(&self) -> Ctxt<'cx> {
+        self.cx
+    }
     pub fn as_varenv(&self) -> VarEnv {
         self.names.as_varenv()
     }
@@ -57,12 +63,14 @@ impl TyEnv {
 
     pub fn insert_type(&self, x: &Label, ty: Type) -> Self {
         TyEnv {
+            cx: self.cx,
             names: self.names.insert(x),
             items: self.items.insert_type(ty),
         }
     }
     pub fn insert_value(&self, x: &Label, e: Nir, ty: Type) -> Self {
         TyEnv {
+            cx: self.cx,
             names: self.names.insert(x),
             items: self.items.insert_value(e, ty),
         }
@@ -72,7 +80,7 @@ impl TyEnv {
     }
 }
 
-impl<'a> From<&'a TyEnv> for NzEnv {
+impl<'a, 'cx> From<&'a TyEnv<'cx>> for NzEnv {
     fn from(x: &'a TyEnv) -> Self {
         x.to_nzenv()
     }
diff --git a/dhall/src/semantics/tck/typecheck.rs b/dhall/src/semantics/tck/typecheck.rs
index 498bd76..7e8c0e1 100644
--- a/dhall/src/semantics/tck/typecheck.rs
+++ b/dhall/src/semantics/tck/typecheck.rs
@@ -5,6 +5,7 @@ use crate::error::{ErrorBuilder, TypeError, TypeMessage};
 use crate::operations::typecheck_operation;
 use crate::semantics::{Hir, HirKind, Nir, NirKind, Tir, TyEnv, Type};
 use crate::syntax::{Const, ExprKind, InterpolatedTextContents, NumKind, Span};
+use crate::Ctxt;
 
 fn function_check(a: Const, b: Const) -> Const {
     if b == Const::Type {
@@ -29,7 +30,7 @@ pub fn mk_span_err<T, S: ToString>(span: Span, msg: S) -> Result<T, TypeError> {
 /// When all sub-expressions have been typed, check the remaining toplevel
 /// layer.
 fn type_one_layer(
-    env: &TyEnv,
+    env: &TyEnv<'_>,
     ekind: ExprKind<Tir<'_>>,
     span: Span,
 ) -> Result<Type, TypeError> {
@@ -58,7 +59,7 @@ fn type_one_layer(
         }),
         ExprKind::Builtin(b) => {
             let t_hir = type_of_builtin(b);
-            typecheck(&t_hir)?.eval_to_type(env)?
+            typecheck(env.cx(), &t_hir)?.eval_to_type(env)?
         }
         ExprKind::TextLit(interpolated) => {
             let text_type = Type::from_builtin(Builtin::Text);
@@ -171,7 +172,7 @@ fn type_one_layer(
 // We pass the annotation to avoid duplicating the annot checking logic. I hope one day we can use
 // it to handle the annotations in merge/toMap/etc. uniformly.
 pub fn type_with<'hir>(
-    env: &TyEnv,
+    env: &TyEnv<'_>,
     hir: &'hir Hir,
     annot: Option<Type>,
 ) -> Result<Tir<'hir>, TypeError> {
@@ -267,15 +268,19 @@ pub fn type_with<'hir>(
 
 /// Typecheck an expression and return the expression annotated with its type if type-checking
 /// succeeded, or an error if type-checking failed.
-pub fn typecheck<'hir>(hir: &'hir Hir) -> Result<Tir<'hir>, TypeError> {
-    type_with(&TyEnv::new(), hir, None)
+pub fn typecheck<'hir>(
+    cx: Ctxt<'_>,
+    hir: &'hir Hir,
+) -> Result<Tir<'hir>, TypeError> {
+    type_with(&TyEnv::new(cx), hir, None)
 }
 
 /// Like `typecheck`, but additionally checks that the expression's type matches the provided type.
 pub fn typecheck_with<'hir>(
+    cx: Ctxt<'_>,
     hir: &'hir Hir,
     ty: &Hir,
 ) -> Result<Tir<'hir>, TypeError> {
-    let ty = typecheck(ty)?.eval_to_type(&TyEnv::new())?;
-    type_with(&TyEnv::new(), hir, Some(ty))
+    let ty = typecheck(cx, ty)?.eval_to_type(&TyEnv::new(cx))?;
+    type_with(&TyEnv::new(cx), hir, Some(ty))
 }