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-rw-r--r--dhall/src/syntax/ast/visitor.rs30
1 files changed, 12 insertions, 18 deletions
diff --git a/dhall/src/syntax/ast/visitor.rs b/dhall/src/syntax/ast/visitor.rs
index c09b8d4..fc90efd 100644
--- a/dhall/src/syntax/ast/visitor.rs
+++ b/dhall/src/syntax/ast/visitor.rs
@@ -10,11 +10,10 @@ use crate::syntax::*;
/// preventing exactly this ! So we have to be more clever. The visitor pattern allows us to have
/// only one mutable thing the whole time: the visitor itself. The visitor can then carry around
/// multiple closures or just one, and Rust is ok with either. See for example TraverseRefVisitor.
-pub trait ExprKindVisitor<'a, SE1, SE2, E1, E2>: Sized {
+pub trait ExprKindVisitor<'a, SE1, SE2>: Sized {
type Error;
fn visit_subexpr(&mut self, subexpr: &'a SE1) -> Result<SE2, Self::Error>;
- fn visit_embed(self, embed: &'a E1) -> Result<E2, Self::Error>;
fn visit_subexpr_under_binder(
mut self,
@@ -26,18 +25,18 @@ pub trait ExprKindVisitor<'a, SE1, SE2, E1, E2>: Sized {
fn visit(
self,
- input: &'a ExprKind<SE1, E1>,
- ) -> Result<ExprKind<SE2, E2>, Self::Error> {
+ input: &'a ExprKind<SE1>,
+ ) -> Result<ExprKind<SE2>, Self::Error> {
visit_ref(self, input)
}
}
-fn visit_ref<'a, V, SE1, SE2, E1, E2>(
+fn visit_ref<'a, V, SE1, SE2>(
mut v: V,
- input: &'a ExprKind<SE1, E1>,
-) -> Result<ExprKind<SE2, E2>, V::Error>
+ input: &'a ExprKind<SE1>,
+) -> Result<ExprKind<SE2>, V::Error>
where
- V: ExprKindVisitor<'a, SE1, SE2, E1, E2>,
+ V: ExprKindVisitor<'a, SE1, SE2>,
{
fn vec<'a, T, U, Err, F: FnMut(&'a T) -> Result<U, Err>>(
x: &'a [T],
@@ -54,27 +53,27 @@ where
None => None,
})
}
- fn dupmap<'a, V, SE1, SE2, E1, E2, T>(
+ fn dupmap<'a, V, SE1, SE2, T>(
x: impl IntoIterator<Item = (&'a Label, &'a SE1)>,
mut v: V,
) -> Result<T, V::Error>
where
SE1: 'a,
T: FromIterator<(Label, SE2)>,
- V: ExprKindVisitor<'a, SE1, SE2, E1, E2>,
+ V: ExprKindVisitor<'a, SE1, SE2>,
{
x.into_iter()
.map(|(k, x)| Ok((k.clone(), v.visit_subexpr(x)?)))
.collect()
}
- fn optdupmap<'a, V, SE1, SE2, E1, E2, T>(
+ fn optdupmap<'a, V, SE1, SE2, T>(
x: impl IntoIterator<Item = (&'a Label, &'a Option<SE1>)>,
mut v: V,
) -> Result<T, V::Error>
where
SE1: 'a,
T: FromIterator<(Label, Option<SE2>)>,
- V: ExprKindVisitor<'a, SE1, SE2, E1, E2>,
+ V: ExprKindVisitor<'a, SE1, SE2>,
{
x.into_iter()
.map(|(k, x)| {
@@ -147,17 +146,15 @@ where
}
Assert(e) => Assert(v.visit_subexpr(e)?),
Import(i) => Import(i.traverse_ref(|e| v.visit_subexpr(e))?),
- Embed(a) => Embed(v.visit_embed(a)?),
})
}
pub struct TraverseRefMaybeBinderVisitor<F>(pub F);
-impl<'a, SE, E, SE2, Err, F> ExprKindVisitor<'a, SE, SE2, E, E>
+impl<'a, SE, SE2, Err, F> ExprKindVisitor<'a, SE, SE2>
for TraverseRefMaybeBinderVisitor<F>
where
SE: 'a,
- E: 'a + Clone,
F: FnMut(Option<&'a Label>, &'a SE) -> Result<SE2, Err>,
{
type Error = Err;
@@ -172,7 +169,4 @@ where
) -> Result<SE2, Self::Error> {
(self.0)(Some(label), subexpr)
}
- fn visit_embed(self, embed: &'a E) -> Result<E, Self::Error> {
- Ok(embed.clone())
- }
}