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-rw-r--r--dhall_syntax/src/core/visitor.rs210
1 files changed, 71 insertions, 139 deletions
diff --git a/dhall_syntax/src/core/visitor.rs b/dhall_syntax/src/core/visitor.rs
index 1377849..dd539e3 100644
--- a/dhall_syntax/src/core/visitor.rs
+++ b/dhall_syntax/src/core/visitor.rs
@@ -16,41 +16,37 @@ pub trait GenericVisitor<Input, Return>: Sized {
/// or just one, and Rust is ok with either. See for example TraverseRefVisitor
/// and TraverseEmbedVisitor.
/// This is very generic. For a more legible trait, see ExprFInFallibleVisitor
-pub trait ExprFVeryGenericVisitor<'a, Ret, SE1, L1, E1>: Sized {
+pub trait ExprFVeryGenericVisitor<'a, Ret, SE1, E1>: Sized {
type Error;
type SE2;
- type L2;
type E2;
fn visit_subexpr(
&mut self,
subexpr: &'a SE1,
) -> Result<Self::SE2, Self::Error>;
- fn visit_label(&mut self, label: &'a L1) -> Result<Self::L2, Self::Error>;
- fn visit_binder(
+ fn visit_subexpr_under_binder(
self,
- label: &'a L1,
+ label: &'a Label,
subexpr: &'a SE1,
- ) -> Result<(Self::L2, Self::SE2), Self::Error>;
+ ) -> Result<Self::SE2, Self::Error>;
fn visit_embed_squash(self, embed: &'a E1) -> Result<Ret, Self::Error>;
// Called with the result of the map, in the non-embed case.
// Useful to change the result type, and/or avoid some loss of info
fn visit_resulting_exprf(
- result: ExprF<Self::SE2, Self::L2, Self::E2>,
+ result: ExprF<Self::SE2, Self::E2>,
) -> Result<Ret, Self::Error>;
}
-impl<'a, T, Ret, SE1, L1, E1>
- GenericVisitor<&'a ExprF<SE1, L1, E1>, Result<Ret, T::Error>> for T
+impl<'a, T, Ret, SE1, E1>
+ GenericVisitor<&'a ExprF<SE1, E1>, Result<Ret, T::Error>> for T
where
- L1: Ord,
- T::L2: Ord,
- T: ExprFVeryGenericVisitor<'a, Ret, SE1, L1, E1>,
+ T: ExprFVeryGenericVisitor<'a, Ret, SE1, E1>,
{
- fn visit(self, input: &'a ExprF<SE1, L1, E1>) -> Result<Ret, T::Error> {
+ fn visit(self, input: &'a ExprF<SE1, E1>) -> Result<Ret, T::Error> {
fn vec<'a, T, U, Err, F: FnMut(&'a T) -> Result<U, Err>>(
x: &'a [T],
f: F,
@@ -66,32 +62,28 @@ where
None => None,
})
}
- fn vecmap<'a, V, Ret, SE, L, E>(
- x: &'a Vec<(L, SE)>,
+ fn vecmap<'a, V, Ret, SE, E>(
+ x: &'a Vec<(Label, SE)>,
mut v: V,
- ) -> Result<Vec<(V::L2, V::SE2)>, V::Error>
+ ) -> Result<Vec<(Label, V::SE2)>, V::Error>
where
- L: Ord,
- V::L2: Ord,
- V: ExprFVeryGenericVisitor<'a, Ret, SE, L, E>,
+ V: ExprFVeryGenericVisitor<'a, Ret, SE, E>,
{
x.iter()
- .map(|(k, x)| Ok((v.visit_label(k)?, v.visit_subexpr(x)?)))
+ .map(|(k, x)| Ok((k.clone(), v.visit_subexpr(x)?)))
.collect()
}
- fn vecoptmap<'a, V, Ret, SE, L, E>(
- x: &'a Vec<(L, Option<SE>)>,
+ fn vecoptmap<'a, V, Ret, SE, E>(
+ x: &'a Vec<(Label, Option<SE>)>,
mut v: V,
- ) -> Result<Vec<(V::L2, Option<V::SE2>)>, V::Error>
+ ) -> Result<Vec<(Label, Option<V::SE2>)>, V::Error>
where
- L: Ord,
- V::L2: Ord,
- V: ExprFVeryGenericVisitor<'a, Ret, SE, L, E>,
+ V: ExprFVeryGenericVisitor<'a, Ret, SE, E>,
{
x.iter()
.map(|(k, x)| {
Ok((
- v.visit_label(k)?,
+ k.clone(),
match x {
Some(x) => Some(v.visit_subexpr(x)?),
None => None,
@@ -104,22 +96,22 @@ where
let mut v = self;
use crate::ExprF::*;
T::visit_resulting_exprf(match input {
- Var(V(l, n)) => Var(V(v.visit_label(l)?, *n)),
+ Var(v) => Var(v.clone()),
Lam(l, t, e) => {
let t = v.visit_subexpr(t)?;
- let (l, e) = v.visit_binder(l, e)?;
- Lam(l, t, e)
+ let e = v.visit_subexpr_under_binder(l, e)?;
+ Lam(l.clone(), t, e)
}
Pi(l, t, e) => {
let t = v.visit_subexpr(t)?;
- let (l, e) = v.visit_binder(l, e)?;
- Pi(l, t, e)
+ let e = v.visit_subexpr_under_binder(l, e)?;
+ Pi(l.clone(), t, e)
}
Let(l, t, a, e) => {
let t = opt(t, &mut |e| v.visit_subexpr(e))?;
let a = v.visit_subexpr(a)?;
- let (l, e) = v.visit_binder(l, e)?;
- Let(l, t, a, e)
+ let e = v.visit_subexpr_under_binder(l, e)?;
+ Let(l.clone(), t, a, e)
}
App(f, a) => App(v.visit_subexpr(f)?, v.visit_subexpr(a)?),
Annot(x, t) => Annot(v.visit_subexpr(x)?, v.visit_subexpr(t)?),
@@ -148,20 +140,16 @@ where
RecordType(kts) => RecordType(vecmap(kts, v)?),
RecordLit(kvs) => RecordLit(vecmap(kvs, v)?),
UnionType(kts) => UnionType(vecoptmap(kts, v)?),
- UnionLit(k, x, kts) => UnionLit(
- v.visit_label(k)?,
- v.visit_subexpr(x)?,
- vecoptmap(kts, v)?,
- ),
+ UnionLit(k, x, kts) => {
+ UnionLit(k.clone(), v.visit_subexpr(x)?, vecoptmap(kts, v)?)
+ }
Merge(x, y, t) => Merge(
v.visit_subexpr(x)?,
v.visit_subexpr(y)?,
opt(t, |e| v.visit_subexpr(e))?,
),
- Field(e, l) => Field(v.visit_subexpr(e)?, v.visit_label(l)?),
- Projection(e, ls) => {
- Projection(v.visit_subexpr(e)?, vec(ls, |l| v.visit_label(l))?)
- }
+ Field(e, l) => Field(v.visit_subexpr(e)?, l.clone()),
+ Projection(e, ls) => Projection(v.visit_subexpr(e)?, ls.clone()),
Embed(a) => return v.visit_embed_squash(a),
})
}
@@ -169,48 +157,35 @@ where
/// Like ExprFVeryGenericVisitor, but sets the return
/// type to ExprF<_>
-pub trait ExprFFallibleVisitor<'a, SE1, SE2, L1, L2, E1, E2>: Sized {
+pub trait ExprFFallibleVisitor<'a, SE1, SE2, E1, E2>: Sized {
type Error;
fn visit_subexpr(&mut self, subexpr: &'a SE1) -> Result<SE2, Self::Error>;
- fn visit_label(&mut self, label: &'a L1) -> Result<L2, Self::Error>;
fn visit_embed(self, embed: &'a E1) -> Result<E2, Self::Error>;
fn visit_subexpr_under_binder(
mut self,
- _label: &'a L1,
+ _label: &'a Label,
subexpr: &'a SE1,
) -> Result<SE2, Self::Error> {
self.visit_subexpr(subexpr)
}
- fn visit_binder(
- mut self,
- label: &'a L1,
- subexpr: &'a SE1,
- ) -> Result<(L2, SE2), Self::Error> {
- Ok((
- self.visit_label(label)?,
- self.visit_subexpr_under_binder(label, subexpr)?,
- ))
- }
-
fn visit_embed_squash(
self,
embed: &'a E1,
- ) -> Result<ExprF<SE2, L2, E2>, Self::Error> {
+ ) -> Result<ExprF<SE2, E2>, Self::Error> {
Ok(ExprF::Embed(self.visit_embed(embed)?))
}
}
-impl<'a, T, SE1, SE2, L1, L2, E1, E2>
- ExprFVeryGenericVisitor<'a, ExprF<SE2, L2, E2>, SE1, L1, E1> for T
+impl<'a, T, SE1, SE2, E1, E2>
+ ExprFVeryGenericVisitor<'a, ExprF<SE2, E2>, SE1, E1> for T
where
- T: ExprFFallibleVisitor<'a, SE1, SE2, L1, L2, E1, E2>,
+ T: ExprFFallibleVisitor<'a, SE1, SE2, E1, E2>,
{
type Error = T::Error;
type SE2 = SE2;
- type L2 = L2;
type E2 = E2;
fn visit_subexpr(
@@ -220,127 +195,105 @@ where
self.visit_subexpr(subexpr)
}
- fn visit_label(&mut self, label: &'a L1) -> Result<Self::L2, Self::Error> {
- self.visit_label(label)
- }
-
- fn visit_binder(
+ fn visit_subexpr_under_binder(
self,
- label: &'a L1,
+ label: &'a Label,
subexpr: &'a SE1,
- ) -> Result<(Self::L2, Self::SE2), Self::Error> {
- self.visit_binder(label, subexpr)
+ ) -> Result<Self::SE2, Self::Error> {
+ self.visit_subexpr_under_binder(label, subexpr)
}
fn visit_embed_squash(
self,
embed: &'a E1,
- ) -> Result<ExprF<SE2, L2, E2>, Self::Error> {
+ ) -> Result<ExprF<SE2, E2>, Self::Error> {
self.visit_embed_squash(embed)
}
// Called with the result of the map, in the non-embed case.
// Useful to change the result type, and/or avoid some loss of info
fn visit_resulting_exprf(
- result: ExprF<Self::SE2, Self::L2, Self::E2>,
- ) -> Result<ExprF<SE2, L2, E2>, Self::Error> {
+ result: ExprF<Self::SE2, Self::E2>,
+ ) -> Result<ExprF<SE2, E2>, Self::Error> {
Ok(result)
}
}
/// Like ExprFFallibleVisitor, but without the error handling.
-pub trait ExprFInFallibleVisitor<'a, SE1, SE2, L1, L2, E1, E2>: Sized {
+pub trait ExprFInFallibleVisitor<'a, SE1, SE2, E1, E2>: Sized {
fn visit_subexpr(&mut self, subexpr: &'a SE1) -> SE2;
- fn visit_label(&mut self, label: &'a L1) -> L2;
fn visit_embed(self, embed: &'a E1) -> E2;
fn visit_subexpr_under_binder(
mut self,
- _label: &'a L1,
+ _label: &'a Label,
subexpr: &'a SE1,
) -> SE2 {
self.visit_subexpr(subexpr)
}
- fn visit_binder(mut self, label: &'a L1, subexpr: &'a SE1) -> (L2, SE2) {
- (
- self.visit_label(label),
- self.visit_subexpr_under_binder(label, subexpr),
- )
- }
-
- fn visit_embed_squash(self, embed: &'a E1) -> ExprF<SE2, L2, E2> {
+ fn visit_embed_squash(self, embed: &'a E1) -> ExprF<SE2, E2> {
ExprF::Embed(self.visit_embed(embed))
}
}
struct InfallibleWrapper<T>(T);
-impl<'a, T, SE1, SE2, L1, L2, E1, E2>
- ExprFFallibleVisitor<'a, SE1, SE2, L1, L2, E1, E2> for InfallibleWrapper<T>
+impl<'a, T, SE1, SE2, E1, E2> ExprFFallibleVisitor<'a, SE1, SE2, E1, E2>
+ for InfallibleWrapper<T>
where
- T: ExprFInFallibleVisitor<'a, SE1, SE2, L1, L2, E1, E2>,
+ T: ExprFInFallibleVisitor<'a, SE1, SE2, E1, E2>,
{
type Error = X;
fn visit_subexpr(&mut self, subexpr: &'a SE1) -> Result<SE2, Self::Error> {
Ok(self.0.visit_subexpr(subexpr))
}
- fn visit_label(&mut self, label: &'a L1) -> Result<L2, Self::Error> {
- Ok(self.0.visit_label(label))
- }
fn visit_embed(self, embed: &'a E1) -> Result<E2, Self::Error> {
Ok(self.0.visit_embed(embed))
}
- fn visit_binder(
+ fn visit_subexpr_under_binder(
self,
- label: &'a L1,
+ label: &'a Label,
subexpr: &'a SE1,
- ) -> Result<(L2, SE2), Self::Error> {
- Ok(self.0.visit_binder(label, subexpr))
+ ) -> Result<SE2, Self::Error> {
+ Ok(self.0.visit_subexpr_under_binder(label, subexpr))
}
fn visit_embed_squash(
self,
embed: &'a E1,
- ) -> Result<ExprF<SE2, L2, E2>, Self::Error> {
+ ) -> Result<ExprF<SE2, E2>, Self::Error> {
Ok(self.0.visit_embed_squash(embed))
}
}
-impl<'a, T, SE1, SE2, L1, L2, E1, E2>
- GenericVisitor<&'a ExprF<SE1, L1, E1>, ExprF<SE2, L2, E2>> for T
+impl<'a, T, SE1, SE2, E1, E2> GenericVisitor<&'a ExprF<SE1, E1>, ExprF<SE2, E2>>
+ for T
where
- L1: Ord,
- L2: Ord,
- T: ExprFInFallibleVisitor<'a, SE1, SE2, L1, L2, E1, E2>,
+ T: ExprFInFallibleVisitor<'a, SE1, SE2, E1, E2>,
{
- fn visit(self, input: &'a ExprF<SE1, L1, E1>) -> ExprF<SE2, L2, E2> {
+ fn visit(self, input: &'a ExprF<SE1, E1>) -> ExprF<SE2, E2> {
trivial_result(InfallibleWrapper(self).visit(input))
}
}
-pub struct TraverseRefWithBindersVisitor<F1, F2, F4, F5> {
+pub struct TraverseRefWithBindersVisitor<F1, F2, F4> {
pub visit_subexpr: F1,
pub visit_under_binder: F2,
pub visit_embed: F4,
- pub visit_label: F5,
}
-impl<'a, SE, L, E, SE2, L2, E2, Err, F1, F2, F4, F5>
- ExprFFallibleVisitor<'a, SE, SE2, L, L2, E, E2>
- for TraverseRefWithBindersVisitor<F1, F2, F4, F5>
+impl<'a, SE, E, SE2, E2, Err, F1, F2, F4>
+ ExprFFallibleVisitor<'a, SE, SE2, E, E2>
+ for TraverseRefWithBindersVisitor<F1, F2, F4>
where
SE: 'a,
- L: 'a,
E: 'a,
- L: Ord,
- L2: Ord,
F1: FnMut(&'a SE) -> Result<SE2, Err>,
- F2: FnOnce(&'a L, &'a SE) -> Result<SE2, Err>,
+ F2: FnOnce(&'a Label, &'a SE) -> Result<SE2, Err>,
F4: FnOnce(&'a E) -> Result<E2, Err>,
- F5: FnMut(&'a L) -> Result<L2, Err>,
{
type Error = Err;
@@ -349,7 +302,7 @@ where
}
fn visit_subexpr_under_binder(
self,
- label: &'a L,
+ label: &'a Label,
subexpr: &'a SE,
) -> Result<SE2, Self::Error> {
(self.visit_under_binder)(label, subexpr)
@@ -357,29 +310,20 @@ where
fn visit_embed(self, embed: &'a E) -> Result<E2, Self::Error> {
(self.visit_embed)(embed)
}
- fn visit_label(&mut self, label: &'a L) -> Result<L2, Self::Error> {
- (self.visit_label)(label)
- }
}
-pub struct TraverseRefVisitor<F1, F3, F4> {
+pub struct TraverseRefVisitor<F1, F3> {
pub visit_subexpr: F1,
pub visit_embed: F3,
- pub visit_label: F4,
}
-impl<'a, SE, L, E, SE2, L2, E2, Err, F1, F3, F4>
- ExprFFallibleVisitor<'a, SE, SE2, L, L2, E, E2>
- for TraverseRefVisitor<F1, F3, F4>
+impl<'a, SE, E, SE2, E2, Err, F1, F3> ExprFFallibleVisitor<'a, SE, SE2, E, E2>
+ for TraverseRefVisitor<F1, F3>
where
SE: 'a,
- L: 'a,
E: 'a,
- L: Ord,
- L2: Ord,
F1: FnMut(&'a SE) -> Result<SE2, Err>,
F3: FnOnce(&'a E) -> Result<E2, Err>,
- F4: FnMut(&'a L) -> Result<L2, Err>,
{
type Error = Err;
@@ -389,15 +333,12 @@ where
fn visit_embed(self, embed: &'a E) -> Result<E2, Self::Error> {
(self.visit_embed)(embed)
}
- fn visit_label(&mut self, label: &'a L) -> Result<L2, Self::Error> {
- (self.visit_label)(label)
- }
}
pub struct TraverseEmbedVisitor<F1>(pub F1);
impl<'a, 'b, N, E, E2, Err, F1>
- ExprFFallibleVisitor<'a, SubExpr<N, E>, SubExpr<N, E2>, Label, Label, E, E2>
+ ExprFFallibleVisitor<'a, SubExpr<N, E>, SubExpr<N, E2>, E, E2>
for &'b mut TraverseEmbedVisitor<F1>
where
N: Clone + 'a,
@@ -414,15 +355,12 @@ where
fn visit_embed(self, embed: &'a E) -> Result<E2, Self::Error> {
(self.0)(embed)
}
- fn visit_label(&mut self, label: &'a Label) -> Result<Label, Self::Error> {
- Ok(Label::clone(label))
- }
}
pub struct NoteAbsurdVisitor;
impl<'a, 'b, N, E>
- ExprFInFallibleVisitor<'a, SubExpr<X, E>, SubExpr<N, E>, Label, Label, E, E>
+ ExprFInFallibleVisitor<'a, SubExpr<X, E>, SubExpr<N, E>, E, E>
for &'b mut NoteAbsurdVisitor
where
E: Clone + 'a,
@@ -433,15 +371,12 @@ where
fn visit_embed(self, embed: &'a E) -> E {
E::clone(embed)
}
- fn visit_label(&mut self, label: &'a Label) -> Label {
- Label::clone(label)
- }
}
pub struct AbsurdVisitor;
impl<'a, 'b, N, E>
- ExprFInFallibleVisitor<'a, SubExpr<X, X>, SubExpr<N, E>, Label, Label, X, E>
+ ExprFInFallibleVisitor<'a, SubExpr<X, X>, SubExpr<N, E>, X, E>
for &'b mut AbsurdVisitor
{
fn visit_subexpr(&mut self, subexpr: &'a SubExpr<X, X>) -> SubExpr<N, E> {
@@ -450,7 +385,4 @@ impl<'a, 'b, N, E>
fn visit_embed(self, embed: &'a X) -> E {
match *embed {}
}
- fn visit_label(&mut self, label: &'a Label) -> Label {
- Label::clone(label)
- }
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-01 11:46:44 +0000