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-rw-r--r--dhall/src/phase/mod.rs131
-rw-r--r--dhall/src/phase/typecheck.rs28
2 files changed, 43 insertions, 116 deletions
diff --git a/dhall/src/phase/mod.rs b/dhall/src/phase/mod.rs
index 0faf6dd..c8a8ffd 100644
--- a/dhall/src/phase/mod.rs
+++ b/dhall/src/phase/mod.rs
@@ -10,7 +10,7 @@ use crate::core::value::{AlphaVar, Value};
use crate::error::{Error, ImportError, TypeError, TypeMessage};
use resolve::ImportRoot;
-use typecheck::{const_to_typed, type_of_const};
+use typecheck::type_of_const;
pub(crate) mod binary;
pub(crate) mod normalize;
@@ -32,10 +32,13 @@ pub(crate) struct Resolved(pub(crate) ResolvedSubExpr);
/// A typed expression
#[derive(Debug, Clone)]
pub(crate) enum Typed {
- // The `Sort` higher-kinded type; it doesn't have a type
- Sort,
- // Any other value, along with (optionally) its type
+ // Any value, along with (optionally) its type
Value(Thunk, Option<Type>),
+ // One of the base higher-kinded typed.
+ // Used to avoid storing the same tower ot Type->Kind->Sort
+ // over and over again. Also enables having Sort as a type
+ // even though it doesn't itself have a type.
+ Const(Const),
}
/// A normalized expression.
@@ -58,14 +61,7 @@ pub struct SimpleType(pub(crate) NormalizedSubExpr);
/// This includes [SimpleType]s but also higher-kinded expressions like
/// `Type`, `Kind` and `{ x: Type }`.
#[derive(Debug, Clone, PartialEq, Eq)]
-pub struct Type(pub(crate) TypeInternal);
-
-#[derive(Debug, Clone)]
-pub(crate) enum TypeInternal {
- Const(Const),
- /// This must not contain a Const value.
- Typed(Box<Typed>),
-}
+pub struct Type(pub(crate) Box<Typed>);
impl Parsed {
pub fn parse_file(f: &Path) -> Result<Parsed, Error> {
@@ -116,7 +112,7 @@ impl Typed {
/// leave ill-typed sub-expressions unevaluated.
pub fn normalize(self) -> Normalized {
match &self {
- Typed::Sort => {}
+ Typed::Const(_) => {}
Typed::Value(thunk, _) => {
thunk.normalize_nf();
}
@@ -130,12 +126,15 @@ impl Typed {
pub(crate) fn from_thunk_untyped(th: Thunk) -> Self {
Typed::Value(th, None)
}
+ pub(crate) fn from_const(c: Const) -> Self {
+ Typed::Const(c)
+ }
// TODO: Avoid cloning if possible
pub(crate) fn to_value(&self) -> Value {
match self {
Typed::Value(th, _) => th.to_value(),
- Typed::Sort => Value::Const(Const::Sort),
+ Typed::Const(c) => Value::Const(*c),
}
}
pub(crate) fn to_expr(&self) -> NormalizedSubExpr {
@@ -147,17 +146,15 @@ impl Typed {
pub(crate) fn to_thunk(&self) -> Thunk {
match self {
Typed::Value(th, _) => th.clone(),
- Typed::Sort => Thunk::from_value(Value::Const(Const::Sort)),
+ Typed::Const(c) => Thunk::from_value(Value::Const(*c)),
}
}
+ // Deprecated
pub(crate) fn to_type(&self) -> Type {
- match self {
- Typed::Sort => Type(TypeInternal::Const(Const::Sort)),
- Typed::Value(th, _) => match &*th.as_value() {
- Value::Const(c) => Type(TypeInternal::Const(*c)),
- _ => Type(TypeInternal::Typed(Box::new(self.clone()))),
- },
- }
+ self.clone().into_type()
+ }
+ pub(crate) fn into_type(self) -> Type {
+ Type(Box::new(self))
}
pub(crate) fn get_type(&self) -> Result<Cow<'_, Type>, TypeError> {
@@ -167,23 +164,17 @@ impl Typed {
&TypecheckContext::new(),
TypeMessage::Untyped,
)),
- Typed::Sort => {
- Err(TypeError::new(&TypecheckContext::new(), TypeMessage::Sort))
- }
+ Typed::Const(c) => Ok(Cow::Owned(type_of_const(*c)?)),
}
}
- pub(crate) fn const_sort() -> Self {
- Typed::Sort
- }
-
pub(crate) fn shift(&self, delta: isize, var: &AlphaVar) -> Self {
match self {
Typed::Value(th, t) => Typed::Value(
th.shift(delta, var),
t.as_ref().map(|x| x.shift(delta, var)),
),
- Typed::Sort => Typed::Sort,
+ Typed::Const(c) => Typed::Const(*c),
}
}
@@ -193,14 +184,14 @@ impl Typed {
th.subst_shift(var, val),
t.as_ref().map(|x| x.subst_shift(var, val)),
),
- Typed::Sort => Typed::Sort,
+ Typed::Const(c) => Typed::Const(*c),
}
}
}
impl Type {
pub(crate) fn to_normalized(&self) -> Normalized {
- self.0.to_normalized()
+ self.0.clone().normalize()
}
pub(crate) fn to_expr(&self) -> NormalizedSubExpr {
self.0.to_expr()
@@ -209,80 +200,37 @@ impl Type {
self.0.to_value()
}
pub(crate) fn as_const(&self) -> Option<Const> {
- self.0.as_const()
+ // TODO: avoid clone
+ match &self.to_value() {
+ Value::Const(c) => Some(*c),
+ _ => None,
+ }
}
pub(crate) fn internal_whnf(&self) -> Option<Value> {
- self.0.whnf()
+ Some(self.to_value())
}
pub(crate) fn get_type(&self) -> Result<Cow<'_, Type>, TypeError> {
self.0.get_type()
}
pub(crate) fn const_sort() -> Self {
- Type(TypeInternal::Const(Const::Sort))
+ Type::from_const(Const::Sort)
}
pub(crate) fn const_kind() -> Self {
- Type(TypeInternal::Const(Const::Kind))
+ Type::from_const(Const::Kind)
}
pub(crate) fn const_type() -> Self {
- Type(TypeInternal::Const(Const::Type))
- }
-
- pub(crate) fn shift(&self, delta: isize, var: &AlphaVar) -> Self {
- Type(self.0.shift(delta, var))
+ Type::from_const(Const::Type)
}
- pub(crate) fn subst_shift(&self, var: &AlphaVar, val: &Typed) -> Self {
- Type(self.0.subst_shift(var, val))
+ pub(crate) fn from_const(c: Const) -> Self {
+ Type(Box::new(Typed::from_const(c)))
}
-}
-impl TypeInternal {
- pub(crate) fn to_typed(&self) -> Typed {
- match self {
- TypeInternal::Typed(e) => e.as_ref().clone(),
- TypeInternal::Const(c) => const_to_typed(*c),
- }
- }
- pub(crate) fn to_normalized(&self) -> Normalized {
- self.to_typed().normalize()
- }
- pub(crate) fn to_expr(&self) -> NormalizedSubExpr {
- self.to_normalized().to_expr()
- }
- pub(crate) fn to_value(&self) -> Value {
- self.to_typed().to_value()
- }
- pub(crate) fn get_type(&self) -> Result<Cow<'_, Type>, TypeError> {
- Ok(match self {
- TypeInternal::Typed(e) => e.get_type()?,
- TypeInternal::Const(c) => Cow::Owned(type_of_const(*c)?),
- })
- }
- pub(crate) fn as_const(&self) -> Option<Const> {
- match self {
- TypeInternal::Const(c) => Some(*c),
- _ => None,
- }
- }
- pub(crate) fn whnf(&self) -> Option<Value> {
- match self {
- TypeInternal::Typed(e) => Some(e.to_value()),
- _ => None,
- }
- }
pub(crate) fn shift(&self, delta: isize, var: &AlphaVar) -> Self {
- use TypeInternal::*;
- match self {
- Typed(e) => Typed(Box::new(e.shift(delta, var))),
- Const(c) => Const(*c),
- }
+ Type(Box::new(self.0.shift(delta, var)))
}
pub(crate) fn subst_shift(&self, var: &AlphaVar, val: &Typed) -> Self {
- use TypeInternal::*;
- match self {
- Typed(e) => Typed(Box::new(e.subst_shift(var, val))),
- Const(c) => Const(*c),
- }
+ Type(Box::new(self.0.subst_shift(var, val)))
}
}
@@ -349,13 +297,6 @@ impl PartialEq for Typed {
}
}
-impl Eq for TypeInternal {}
-impl PartialEq for TypeInternal {
- fn eq(&self, other: &Self) -> bool {
- self.to_normalized() == other.to_normalized()
- }
-}
-
impl Display for Typed {
fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
self.to_expr().fmt(f)
diff --git a/dhall/src/phase/typecheck.rs b/dhall/src/phase/typecheck.rs
index 42a4540..3e6986f 100644
--- a/dhall/src/phase/typecheck.rs
+++ b/dhall/src/phase/typecheck.rs
@@ -12,7 +12,7 @@ use crate::core::context::{NormalizationContext, TypecheckContext};
use crate::core::thunk::{Thunk, TypeThunk};
use crate::core::value::Value;
use crate::error::{TypeError, TypeMessage};
-use crate::phase::{Normalized, Resolved, Type, TypeInternal, Typed};
+use crate::phase::{Normalized, Resolved, Type, Typed};
macro_rules! ensure_equal {
($x:expr, $y:expr, $err:expr $(,)*) => {
@@ -97,7 +97,7 @@ impl TypeIntermediate {
TypeThunk::from_type(tb.clone()),
)
.into_thunk(),
- const_to_type(k),
+ Type::from_const(k),
)
}
TypeIntermediate::RecordType(ctx, kts) => {
@@ -127,7 +127,7 @@ impl TypeIntermediate {
.collect(),
)
.into_thunk(),
- const_to_type(k),
+ Type::from_const(k),
)
}
TypeIntermediate::UnionType(ctx, kts) => {
@@ -166,7 +166,7 @@ impl TypeIntermediate {
.collect(),
)
.into_thunk(),
- const_to_type(k),
+ Type::from_const(k),
)
}
TypeIntermediate::ListType(ctx, t) => {
@@ -178,7 +178,7 @@ impl TypeIntermediate {
Value::from_builtin(Builtin::List)
.app(t.to_value())
.into_thunk(),
- const_to_type(Const::Type),
+ Type::from_const(Const::Type),
)
}
TypeIntermediate::OptionalType(ctx, t) => {
@@ -190,7 +190,7 @@ impl TypeIntermediate {
Value::from_builtin(Builtin::Optional)
.app(t.to_value())
.into_thunk(),
- const_to_type(Const::Type),
+ Type::from_const(Const::Type),
)
}
})
@@ -217,20 +217,6 @@ where
eL0.borrow().to_value() == eR0.borrow().to_value()
}
-pub(crate) fn const_to_typed(c: Const) -> Typed {
- match c {
- Const::Sort => Typed::const_sort(),
- _ => Typed::from_thunk_and_type(
- Value::Const(c).into_thunk(),
- type_of_const(c).unwrap(),
- ),
- }
-}
-
-fn const_to_type(c: Const) -> Type {
- Type(TypeInternal::Const(c))
-}
-
pub(crate) fn type_of_const(c: Const) -> Result<Type, TypeError> {
match c {
Const::Type => Ok(Type::const_kind()),
@@ -647,7 +633,7 @@ fn type_last_layer(
// ))),
}
}
- Const(c) => Ok(RetTyped(const_to_typed(c))),
+ Const(c) => Ok(RetTyped(Typed::from_const(c))),
Builtin(b) => {
Ok(RetType(mktype(ctx, rc(type_of_builtin(b)).note_absurd())?))
}