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-rw-r--r--dhall/src/semantics/tck/env.rs137
-rw-r--r--dhall/src/semantics/tck/mod.rs2
-rw-r--r--dhall/src/semantics/tck/tyexpr.rs6
-rw-r--r--dhall/src/semantics/tck/typecheck.rs58
4 files changed, 144 insertions, 59 deletions
diff --git a/dhall/src/semantics/tck/env.rs b/dhall/src/semantics/tck/env.rs
new file mode 100644
index 0000000..32c2f21
--- /dev/null
+++ b/dhall/src/semantics/tck/env.rs
@@ -0,0 +1,137 @@
+use crate::semantics::{AlphaVar, NzEnv, NzVar, TyExprKind, Type, Value};
+use crate::syntax::{Label, V};
+
+/// Environment for indexing variables.
+#[derive(Debug, Clone, Copy)]
+pub(crate) struct VarEnv {
+ size: usize,
+}
+
+/// Environment for resolving names.
+#[derive(Debug, Clone)]
+pub(crate) struct NameEnv {
+ names: Vec<Label>,
+}
+
+/// Environment for typing expressions.
+#[derive(Debug, Clone)]
+pub(crate) struct TyEnv {
+ names: NameEnv,
+ items: NzEnv,
+}
+
+impl VarEnv {
+ pub fn new() -> Self {
+ VarEnv { size: 0 }
+ }
+ pub fn size(&self) -> usize {
+ self.size
+ }
+ pub fn insert(&self) -> Self {
+ VarEnv {
+ size: self.size + 1,
+ }
+ }
+ pub fn lookup(&self, var: &NzVar) -> AlphaVar {
+ self.lookup_fallible(var).unwrap()
+ }
+ pub fn lookup_fallible(&self, var: &NzVar) -> Option<AlphaVar> {
+ let idx = self.size.checked_sub(var.idx() + 1)?;
+ Some(AlphaVar::new(V((), idx)))
+ }
+}
+
+impl NameEnv {
+ pub fn new() -> Self {
+ NameEnv { names: Vec::new() }
+ }
+ pub fn from_binders(names: impl Iterator<Item = Label>) -> Self {
+ NameEnv {
+ names: names.collect(),
+ }
+ }
+ pub fn as_varenv(&self) -> VarEnv {
+ VarEnv {
+ size: self.names.len(),
+ }
+ }
+
+ pub fn insert(&self, x: &Label) -> Self {
+ let mut env = self.clone();
+ env.insert_mut(x);
+ env
+ }
+ pub fn insert_mut(&mut self, x: &Label) {
+ self.names.push(x.clone())
+ }
+ pub fn remove_mut(&mut self) {
+ self.names.pop();
+ }
+
+ pub fn unlabel_var(&self, var: &V<Label>) -> Option<AlphaVar> {
+ let V(name, idx) = var;
+ let (idx, _) = self
+ .names
+ .iter()
+ .rev()
+ .enumerate()
+ .filter(|(_, n)| *n == name)
+ .nth(*idx)?;
+ Some(AlphaVar::new(V((), idx)))
+ }
+ pub fn label_var(&self, var: &AlphaVar) -> V<Label> {
+ let name = &self.names[self.names.len() - 1 - var.idx()];
+ let idx = self
+ .names
+ .iter()
+ .rev()
+ .take(var.idx())
+ .filter(|n| *n == name)
+ .count();
+ V(name.clone(), idx)
+ }
+}
+
+impl TyEnv {
+ pub fn new() -> Self {
+ TyEnv {
+ names: NameEnv::new(),
+ items: NzEnv::new(),
+ }
+ }
+ pub fn from_nzenv_alpha(items: &NzEnv) -> Self {
+ TyEnv {
+ names: NameEnv::from_binders(
+ std::iter::repeat("_".into()).take(items.size()),
+ ),
+ items: items.clone(),
+ }
+ }
+ pub fn as_varenv(&self) -> VarEnv {
+ self.names.as_varenv()
+ }
+ pub fn as_nzenv(&self) -> &NzEnv {
+ &self.items
+ }
+ pub fn as_nameenv(&self) -> &NameEnv {
+ &self.names
+ }
+
+ pub fn insert_type(&self, x: &Label, t: Type) -> Self {
+ TyEnv {
+ names: self.names.insert(x),
+ items: self.items.insert_type(t),
+ }
+ }
+ pub fn insert_value(&self, x: &Label, e: Value) -> Self {
+ TyEnv {
+ names: self.names.insert(x),
+ items: self.items.insert_value(e),
+ }
+ }
+ pub fn lookup(&self, var: &V<Label>) -> Option<(TyExprKind, Type)> {
+ let var = self.names.unlabel_var(var)?;
+ let ty = self.items.lookup_val(&var).get_type().unwrap();
+ Some((TyExprKind::Var(var), ty))
+ }
+}
diff --git a/dhall/src/semantics/tck/mod.rs b/dhall/src/semantics/tck/mod.rs
index ba95847..28974af 100644
--- a/dhall/src/semantics/tck/mod.rs
+++ b/dhall/src/semantics/tck/mod.rs
@@ -1,4 +1,6 @@
pub mod context;
+pub mod env;
pub mod tyexpr;
pub mod typecheck;
+pub(crate) use env::*;
pub(crate) use tyexpr::*;
diff --git a/dhall/src/semantics/tck/tyexpr.rs b/dhall/src/semantics/tck/tyexpr.rs
index b64c519..262cda6 100644
--- a/dhall/src/semantics/tck/tyexpr.rs
+++ b/dhall/src/semantics/tck/tyexpr.rs
@@ -1,12 +1,10 @@
use crate::error::{TypeError, TypeMessage};
use crate::semantics::core::var::AlphaVar;
-use crate::semantics::nze::nzexpr::NameEnv;
-use crate::semantics::phase::normalize::{normalize_tyexpr_whnf, NzEnv};
+use crate::semantics::phase::normalize::normalize_tyexpr_whnf;
use crate::semantics::phase::typecheck::rc;
use crate::semantics::phase::Normalized;
use crate::semantics::phase::{NormalizedExpr, ToExprOptions};
-use crate::semantics::tck::typecheck::TyEnv;
-use crate::semantics::Value;
+use crate::semantics::{NameEnv, NzEnv, TyEnv, Value};
use crate::syntax::{ExprKind, Span, V};
pub(crate) type Type = Value;
diff --git a/dhall/src/semantics/tck/typecheck.rs b/dhall/src/semantics/tck/typecheck.rs
index 7a225f7..789105f 100644
--- a/dhall/src/semantics/tck/typecheck.rs
+++ b/dhall/src/semantics/tck/typecheck.rs
@@ -3,71 +3,19 @@ use std::cmp::max;
use std::collections::HashMap;
use crate::error::{TypeError, TypeMessage};
-use crate::semantics::nze::{NameEnv, NzVar, VarEnv};
-use crate::semantics::phase::normalize::{merge_maps, NzEnv};
+use crate::semantics::phase::normalize::merge_maps;
use crate::semantics::phase::typecheck::{
builtin_to_value, const_to_value, type_of_builtin,
};
use crate::semantics::phase::Normalized;
use crate::semantics::{
- Binder, Closure, TyExpr, TyExprKind, Type, Value, ValueKind,
+ Binder, Closure, NzVar, TyEnv, TyExpr, TyExprKind, Type, Value, ValueKind,
};
use crate::syntax;
use crate::syntax::{
- BinOp, Builtin, Const, Expr, ExprKind, InterpolatedTextContents, Label,
- Span, V,
+ BinOp, Builtin, Const, Expr, ExprKind, InterpolatedTextContents, Span,
};
-#[derive(Debug, Clone)]
-pub(crate) struct TyEnv {
- names: NameEnv,
- items: NzEnv,
-}
-
-impl TyEnv {
- pub fn new() -> Self {
- TyEnv {
- names: NameEnv::new(),
- items: NzEnv::new(),
- }
- }
- pub fn from_nzenv_alpha(items: &NzEnv) -> Self {
- TyEnv {
- names: NameEnv::from_binders(
- std::iter::repeat("_".into()).take(items.size()),
- ),
- items: items.clone(),
- }
- }
- pub fn as_varenv(&self) -> VarEnv {
- self.names.as_varenv()
- }
- pub fn as_nzenv(&self) -> &NzEnv {
- &self.items
- }
- pub fn as_nameenv(&self) -> &NameEnv {
- &self.names
- }
-
- pub fn insert_type(&self, x: &Label, t: Type) -> Self {
- TyEnv {
- names: self.names.insert(x),
- items: self.items.insert_type(t),
- }
- }
- pub fn insert_value(&self, x: &Label, e: Value) -> Self {
- TyEnv {
- names: self.names.insert(x),
- items: self.items.insert_value(e),
- }
- }
- pub fn lookup(&self, var: &V<Label>) -> Option<(TyExprKind, Type)> {
- let var = self.names.unlabel_var(var)?;
- let ty = self.items.lookup_val(&var).get_type().unwrap();
- Some((TyExprKind::Var(var), ty))
- }
-}
-
fn type_of_recordtype<'a>(
tys: impl Iterator<Item = Cow<'a, TyExpr>>,
) -> Result<Type, TypeError> {
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-24 17:21:11 +0000