diff options
Diffstat (limited to 'dhall/src/syntax/ast/visitor.rs')
-rw-r--r-- | dhall/src/syntax/ast/visitor.rs | 47 |
1 files changed, 24 insertions, 23 deletions
diff --git a/dhall/src/syntax/ast/visitor.rs b/dhall/src/syntax/ast/visitor.rs index b76d037..b557995 100644 --- a/dhall/src/syntax/ast/visitor.rs +++ b/dhall/src/syntax/ast/visitor.rs @@ -1,7 +1,7 @@ use crate::syntax::*; use std::iter::FromIterator; -/// A visitor trait that can be used to traverse `ExprF`s. We need this pattern so that Rust lets +/// A visitor trait that can be used to traverse `ExprKind`s. We need this pattern so that Rust lets /// us have as much mutability as we can. /// For example, `traverse_ref_with_special_handling_of_binders` cannot be made using only /// `traverse_ref`, because `traverse_ref` takes a `FnMut` so we would need to pass multiple @@ -9,7 +9,7 @@ use std::iter::FromIterator; /// 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 ExprFVisitor<'a, SE1, SE2, E1, E2>: Sized { +pub trait ExprKindVisitor<'a, SE1, SE2, E1, E2>: Sized { type Error; fn visit_subexpr(&mut self, subexpr: &'a SE1) -> Result<SE2, Self::Error>; @@ -25,14 +25,14 @@ pub trait ExprFVisitor<'a, SE1, SE2, E1, E2>: Sized { fn visit( self, - input: &'a ExprF<SE1, E1>, - ) -> Result<ExprF<SE2, E2>, Self::Error> { + input: &'a ExprKind<SE1, E1>, + ) -> Result<ExprKind<SE2, E2>, Self::Error> { visit_ref(self, input) } } -/// Like `ExprFVisitor`, but by mutable reference -pub trait ExprFMutVisitor<'a, SE, E>: Sized { +/// Like `ExprKindVisitor`, but by mutable reference +pub trait ExprKindMutVisitor<'a, SE, E>: Sized { type Error; fn visit_subexpr(&mut self, subexpr: &'a mut SE) @@ -49,17 +49,17 @@ pub trait ExprFMutVisitor<'a, SE, E>: Sized { self.visit_subexpr(subexpr) } - fn visit(self, input: &'a mut ExprF<SE, E>) -> Result<(), Self::Error> { + fn visit(self, input: &'a mut ExprKind<SE, E>) -> Result<(), Self::Error> { visit_mut(self, input) } } fn visit_ref<'a, V, SE1, SE2, E1, E2>( mut v: V, - input: &'a ExprF<SE1, E1>, -) -> Result<ExprF<SE2, E2>, V::Error> + input: &'a ExprKind<SE1, E1>, +) -> Result<ExprKind<SE2, E2>, V::Error> where - V: ExprFVisitor<'a, SE1, SE2, E1, E2>, + V: ExprKindVisitor<'a, SE1, SE2, E1, E2>, { fn vec<'a, T, U, Err, F: FnMut(&'a T) -> Result<U, Err>>( x: &'a [T], @@ -83,7 +83,7 @@ where where SE1: 'a, T: FromIterator<(Label, SE2)>, - V: ExprFVisitor<'a, SE1, SE2, E1, E2>, + V: ExprKindVisitor<'a, SE1, SE2, E1, E2>, { x.into_iter() .map(|(k, x)| Ok((k.clone(), v.visit_subexpr(x)?))) @@ -96,7 +96,7 @@ where where SE1: 'a, T: FromIterator<(Label, Option<SE2>)>, - V: ExprFVisitor<'a, SE1, SE2, E1, E2>, + V: ExprKindVisitor<'a, SE1, SE2, E1, E2>, { x.into_iter() .map(|(k, x)| { @@ -111,7 +111,7 @@ where .collect() } - use crate::syntax::ExprF::*; + use crate::syntax::ExprKind::*; Ok(match input { Var(v) => Var(v.clone()), Lam(l, t, e) => { @@ -172,14 +172,14 @@ where fn visit_mut<'a, V, SE, E>( mut v: V, - input: &'a mut ExprF<SE, E>, + input: &'a mut ExprKind<SE, E>, ) -> Result<(), V::Error> where - V: ExprFMutVisitor<'a, SE, E>, + V: ExprKindMutVisitor<'a, SE, E>, { fn vec<'a, V, SE, E>(v: &mut V, x: &'a mut Vec<SE>) -> Result<(), V::Error> where - V: ExprFMutVisitor<'a, SE, E>, + V: ExprKindMutVisitor<'a, SE, E>, { for x in x { v.visit_subexpr(x)?; @@ -191,7 +191,7 @@ where x: &'a mut Option<SE>, ) -> Result<(), V::Error> where - V: ExprFMutVisitor<'a, SE, E>, + V: ExprKindMutVisitor<'a, SE, E>, { if let Some(x) = x { v.visit_subexpr(x)?; @@ -204,7 +204,7 @@ where ) -> Result<(), V::Error> where SE: 'a, - V: ExprFMutVisitor<'a, SE, E>, + V: ExprKindMutVisitor<'a, SE, E>, { for (_, x) in x { v.visit_subexpr(x)?; @@ -217,7 +217,7 @@ where ) -> Result<(), V::Error> where SE: 'a, - V: ExprFMutVisitor<'a, SE, E>, + V: ExprKindMutVisitor<'a, SE, E>, { for (_, x) in x { opt(&mut v, x)?; @@ -225,7 +225,7 @@ where Ok(()) } - use crate::syntax::ExprF::*; + use crate::syntax::ExprKind::*; match input { Var(_) | Const(_) | Builtin(_) | BoolLit(_) | NaturalLit(_) | IntegerLit(_) | DoubleLit(_) => {} @@ -293,7 +293,7 @@ pub struct TraverseRefWithBindersVisitor<F1, F2> { pub visit_under_binder: F2, } -impl<'a, SE, E, SE2, Err, F1, F2> ExprFVisitor<'a, SE, SE2, E, E> +impl<'a, SE, E, SE2, Err, F1, F2> ExprKindVisitor<'a, SE, SE2, E, E> for TraverseRefWithBindersVisitor<F1, F2> where SE: 'a, @@ -322,7 +322,7 @@ pub struct TraverseRefVisitor<F1> { pub visit_subexpr: F1, } -impl<'a, SE, E, SE2, Err, F1> ExprFVisitor<'a, SE, SE2, E, E> +impl<'a, SE, E, SE2, Err, F1> ExprKindVisitor<'a, SE, SE2, E, E> for TraverseRefVisitor<F1> where SE: 'a, @@ -343,7 +343,8 @@ pub struct TraverseMutVisitor<F1> { pub visit_subexpr: F1, } -impl<'a, SE, E, Err, F1> ExprFMutVisitor<'a, SE, E> for TraverseMutVisitor<F1> +impl<'a, SE, E, Err, F1> ExprKindMutVisitor<'a, SE, E> + for TraverseMutVisitor<F1> where SE: 'a, E: 'a, |