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-rw-r--r--dhall/src/core/context.rs166
-rw-r--r--dhall/src/core/var.rs12
-rw-r--r--dhall/src/error/mod.rs6
-rw-r--r--dhall/src/phase/mod.rs3
-rw-r--r--dhall/src/phase/typecheck.rs4
5 files changed, 115 insertions, 76 deletions
diff --git a/dhall/src/core/context.rs b/dhall/src/core/context.rs
index e693317..aeec7fb 100644
--- a/dhall/src/core/context.rs
+++ b/dhall/src/core/context.rs
@@ -1,66 +1,88 @@
use std::borrow::Cow;
use std::rc::Rc;
-use dhall_syntax::context::Context;
+use dhall_syntax::context::Context as SimpleContext;
use dhall_syntax::{Label, V};
use crate::core::thunk::Thunk;
use crate::core::value::Value;
use crate::core::var::{AlphaVar, Shift, Subst};
-use crate::phase::{Normalized, Type, Typed};
+use crate::error::TypeError;
+use crate::phase::{Type, Typed};
#[derive(Debug, Clone)]
-enum NzEnvItem {
- Thunk(Thunk),
- Skip(AlphaVar),
+pub(crate) enum CtxItem<T> {
+ Kept(AlphaVar, T),
+ Replaced(Thunk, T),
}
#[derive(Debug, Clone)]
-pub(crate) struct NormalizationContext(Rc<Context<Label, NzEnvItem>>);
+pub(crate) struct Context<T>(Rc<SimpleContext<Label, CtxItem<T>>>);
#[derive(Debug, Clone)]
-pub(crate) enum TyEnvItem {
- Type(AlphaVar, Type),
- Value(Normalized),
-}
+pub(crate) struct NormalizationContext(Context<()>);
#[derive(Debug, Clone)]
-pub(crate) struct TypecheckContext(pub(crate) Context<Label, TyEnvItem>);
+pub(crate) struct TypecheckContext(Context<Type>);
+
+impl<T> CtxItem<T> {
+ fn forget(&self) -> CtxItem<()> {
+ match self {
+ CtxItem::Kept(var, _) => CtxItem::Kept(var.clone(), ()),
+ CtxItem::Replaced(e, _) => CtxItem::Replaced(e.clone(), ()),
+ }
+ }
+}
+
+impl<T> Context<T> {
+ pub(crate) fn new() -> Self {
+ Context(Rc::new(SimpleContext::new()))
+ }
+ pub(crate) fn forget(&self) -> Context<()> {
+ let mut ctx = SimpleContext::new();
+ for (k, vs) in self.0.iter_keys() {
+ for v in vs.iter() {
+ ctx = ctx.insert(k.clone(), v.forget());
+ }
+ }
+ Context(Rc::new(ctx))
+ }
+ pub(crate) fn insert_kept(&self, x: &Label, t: T) -> Self
+ where
+ T: Shift + Clone,
+ {
+ Context(Rc::new(self.0.map(|_, e| e.shift(1, &x.into())).insert(
+ x.clone(),
+ CtxItem::Kept(x.into(), t.shift(1, &x.into())),
+ )))
+ }
+ pub(crate) fn insert_replaced(&self, x: &Label, e: Thunk, t: T) -> Self
+ where
+ T: Clone,
+ {
+ Context(Rc::new(self.0.insert(x.clone(), CtxItem::Replaced(e, t))))
+ }
+ pub(crate) fn lookup(&self, var: &V<Label>) -> Option<&CtxItem<T>> {
+ let V(x, n) = var;
+ self.0.lookup(x, *n)
+ }
+}
impl NormalizationContext {
pub(crate) fn new() -> Self {
- NormalizationContext(Rc::new(Context::new()))
+ NormalizationContext(Context::new())
}
pub(crate) fn skip(&self, x: &Label) -> Self {
- NormalizationContext(Rc::new(
- self.0
- .map(|_, e| e.shift(1, &x.into()))
- .insert(x.clone(), NzEnvItem::Skip(x.into())),
- ))
+ NormalizationContext(self.0.insert_kept(x, ()))
}
pub(crate) fn lookup(&self, var: &V<Label>) -> Value {
- let V(x, n) = var;
- match self.0.lookup(x, *n) {
- Some(NzEnvItem::Thunk(t)) => t.to_value(),
- Some(NzEnvItem::Skip(newvar)) => Value::Var(newvar.clone()),
+ match self.0.lookup(var) {
+ Some(CtxItem::Replaced(t, ())) => t.to_value(),
+ Some(CtxItem::Kept(newvar, ())) => Value::Var(newvar.clone()),
// Free variable
None => Value::Var(AlphaVar::from_var(var.clone())),
}
}
- pub(crate) fn from_typecheck_ctx(tc_ctx: &TypecheckContext) -> Self {
- use TyEnvItem::*;
- let mut ctx = Context::new();
- for (k, vs) in tc_ctx.0.iter_keys() {
- for v in vs.iter() {
- let new_item = match v {
- Type(var, _) => NzEnvItem::Skip(var.clone()),
- Value(e) => NzEnvItem::Thunk(e.to_thunk()),
- };
- ctx = ctx.insert(k.clone(), new_item);
- }
- }
- NormalizationContext(Rc::new(ctx))
- }
}
impl TypecheckContext {
@@ -68,68 +90,82 @@ impl TypecheckContext {
TypecheckContext(Context::new())
}
pub(crate) fn insert_type(&self, x: &Label, t: Type) -> Self {
- TypecheckContext(self.0.map(|_, e| e.shift(1, &x.into())).insert(
- x.clone(),
- TyEnvItem::Type(x.into(), t.shift(1, &x.into())),
- ))
+ TypecheckContext(self.0.insert_kept(x, t))
}
- pub(crate) fn insert_value(&self, x: &Label, t: Normalized) -> Self {
- TypecheckContext(self.0.insert(x.clone(), TyEnvItem::Value(t)))
+ pub(crate) fn insert_value(
+ &self,
+ x: &Label,
+ e: Typed,
+ ) -> Result<Self, TypeError> {
+ Ok(TypecheckContext(self.0.insert_replaced(
+ x,
+ e.to_thunk(),
+ e.get_type()?.into_owned(),
+ )))
}
pub(crate) fn lookup(&self, var: &V<Label>) -> Option<Cow<'_, Type>> {
- let V(x, n) = var;
- match self.0.lookup(x, *n) {
- Some(TyEnvItem::Type(_, t)) => Some(Cow::Borrowed(&t)),
- Some(TyEnvItem::Value(t)) => Some(t.get_type()?),
+ match self.0.lookup(var) {
+ Some(CtxItem::Kept(_, t)) => Some(Cow::Borrowed(&t)),
+ Some(CtxItem::Replaced(_, t)) => Some(Cow::Borrowed(&t)),
None => None,
}
}
pub(crate) fn to_normalization_ctx(&self) -> NormalizationContext {
- NormalizationContext::from_typecheck_ctx(self)
+ NormalizationContext(self.0.forget())
}
}
-impl Shift for NzEnvItem {
+impl<T: Shift> Shift for CtxItem<T> {
fn shift(&self, delta: isize, var: &AlphaVar) -> Self {
- use NzEnvItem::*;
match self {
- Thunk(e) => Thunk(e.shift(delta, var)),
- Skip(v) => Skip(v.shift(delta, var)),
+ CtxItem::Kept(v, t) => {
+ CtxItem::Kept(v.shift(delta, var), t.shift(delta, var))
+ }
+ CtxItem::Replaced(e, t) => {
+ CtxItem::Replaced(e.shift(delta, var), t.shift(delta, var))
+ }
}
}
}
-impl Shift for NormalizationContext {
+impl<T: Shift> Shift for Context<T> {
fn shift(&self, delta: isize, var: &AlphaVar) -> Self {
- NormalizationContext(Rc::new(self.0.map(|_, e| e.shift(delta, var))))
+ Context(Rc::new(self.0.map(|_, e| e.shift(delta, var))))
}
}
-impl Shift for TyEnvItem {
+impl Shift for NormalizationContext {
fn shift(&self, delta: isize, var: &AlphaVar) -> Self {
- use TyEnvItem::*;
- match self {
- Type(v, e) => Type(v.shift(delta, var), e.shift(delta, var)),
- Value(e) => Value(e.shift(delta, var)),
- }
+ NormalizationContext(self.0.shift(delta, var))
}
}
-impl Subst<Typed> for NzEnvItem {
+impl<T: Subst<Typed>> Subst<Typed> for CtxItem<T> {
fn subst_shift(&self, var: &AlphaVar, val: &Typed) -> Self {
match self {
- NzEnvItem::Thunk(e) => NzEnvItem::Thunk(e.subst_shift(var, val)),
- NzEnvItem::Skip(v) if v == var => NzEnvItem::Thunk(val.to_thunk()),
- NzEnvItem::Skip(v) => NzEnvItem::Skip(v.shift(-1, var)),
+ CtxItem::Replaced(e, t) => CtxItem::Replaced(
+ e.subst_shift(var, val),
+ t.subst_shift(var, val),
+ ),
+ CtxItem::Kept(v, t) if v == var => {
+ CtxItem::Replaced(val.to_thunk(), t.subst_shift(var, val))
+ }
+ CtxItem::Kept(v, t) => {
+ CtxItem::Kept(v.shift(-1, var), t.subst_shift(var, val))
+ }
}
}
}
+impl<T: Subst<Typed>> Subst<Typed> for Context<T> {
+ fn subst_shift(&self, var: &AlphaVar, val: &Typed) -> Self {
+ Context(Rc::new(self.0.map(|_, e| e.subst_shift(var, val))))
+ }
+}
+
impl Subst<Typed> for NormalizationContext {
fn subst_shift(&self, var: &AlphaVar, val: &Typed) -> Self {
- NormalizationContext(Rc::new(
- self.0.map(|_, e| e.subst_shift(var, val)),
- ))
+ NormalizationContext(self.0.subst_shift(var, val))
}
}
diff --git a/dhall/src/core/var.rs b/dhall/src/core/var.rs
index 21bc06b..2a564bf 100644
--- a/dhall/src/core/var.rs
+++ b/dhall/src/core/var.rs
@@ -62,6 +62,18 @@ impl Shift for AlphaVar {
}
}
+impl Shift for () {
+ fn shift(&self, _delta: isize, _var: &AlphaVar) -> Self {
+ ()
+ }
+}
+
+impl<T> Subst<T> for () {
+ fn subst_shift(&self, _var: &AlphaVar, _val: &T) -> Self {
+ ()
+ }
+}
+
impl std::cmp::PartialEq for AlphaVar {
fn eq(&self, other: &Self) -> bool {
match (&self.alpha, &other.alpha) {
diff --git a/dhall/src/error/mod.rs b/dhall/src/error/mod.rs
index f84d078..bb1acbd 100644
--- a/dhall/src/error/mod.rs
+++ b/dhall/src/error/mod.rs
@@ -78,12 +78,6 @@ impl TypeError {
}
}
-impl From<TypeError> for std::option::NoneError {
- fn from(_: TypeError) -> std::option::NoneError {
- std::option::NoneError
- }
-}
-
impl std::error::Error for TypeMessage {
fn description(&self) -> &str {
use TypeMessage::*;
diff --git a/dhall/src/phase/mod.rs b/dhall/src/phase/mod.rs
index 5c910bc..d658638 100644
--- a/dhall/src/phase/mod.rs
+++ b/dhall/src/phase/mod.rs
@@ -223,9 +223,6 @@ impl Normalized {
pub(crate) fn to_value(&self) -> Value {
self.0.to_value()
}
- pub(crate) fn to_thunk(&self) -> Thunk {
- self.0.to_thunk()
- }
pub(crate) fn to_type(self) -> Type {
self.0.to_type()
}
diff --git a/dhall/src/phase/typecheck.rs b/dhall/src/phase/typecheck.rs
index f8ee559..bfe85b9 100644
--- a/dhall/src/phase/typecheck.rs
+++ b/dhall/src/phase/typecheck.rs
@@ -378,8 +378,8 @@ fn type_with(
v.clone()
};
- let v = type_with(ctx, v)?.normalize();
- let e = type_with(&ctx.insert_value(x, v.clone()), e.clone())?;
+ let v = type_with(ctx, v)?;
+ let e = type_with(&ctx.insert_value(x, v.clone())?, e.clone())?;
Ok(RetType(e.get_type()?.into_owned()))
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-24 13:48:56 +0000