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-rw-r--r--dhall/src/syntax/ast/expr.rs84
-rw-r--r--dhall/src/syntax/ast/visitor.rs42
-rw-r--r--dhall/src/syntax/binary/decode.rs2
l---------dhall/src/syntax/text/dhall.abnf1
-rw-r--r--dhall/src/syntax/text/dhall.pest.visibility (renamed from dhall/src/dhall.pest.visibility)0
-rw-r--r--dhall/src/syntax/text/parser.rs4
-rw-r--r--dhall/src/syntax/text/printer.rs2
7 files changed, 52 insertions, 83 deletions
diff --git a/dhall/src/syntax/ast/expr.rs b/dhall/src/syntax/ast/expr.rs
index 68cb524..28a0aee 100644
--- a/dhall/src/syntax/ast/expr.rs
+++ b/dhall/src/syntax/ast/expr.rs
@@ -24,7 +24,7 @@ pub enum Const {
/// The `Int` field is a DeBruijn index.
/// See dhall-lang/standard/semantics.md for details
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct V<Label>(pub Label, pub usize);
+pub struct V(pub Label, pub usize);
// Definition order must match precedence order for
// pretty-printing to work correctly
@@ -112,7 +112,7 @@ pub enum ExprKind<SubExpr, Embed> {
Const(Const),
/// `x`
/// `x@n`
- Var(V<Label>),
+ Var(V),
/// `λ(x : A) -> b`
Lam(Label, SubExpr, SubExpr),
/// `A -> B`
@@ -174,29 +174,38 @@ pub enum ExprKind<SubExpr, Embed> {
}
impl<SE, E> ExprKind<SE, E> {
+ pub fn traverse_ref_maybe_binder<'a, SE2, Err>(
+ &'a self,
+ visit: impl FnMut(Option<&'a Label>, &'a SE) -> Result<SE2, Err>,
+ ) -> Result<ExprKind<SE2, E>, Err>
+ where
+ E: Clone,
+ {
+ visitor::TraverseRefMaybeBinderVisitor(visit).visit(self)
+ }
+
pub fn traverse_ref_with_special_handling_of_binders<'a, SE2, Err>(
&'a self,
- visit_subexpr: impl FnMut(&'a SE) -> Result<SE2, Err>,
- visit_under_binder: impl FnOnce(&'a Label, &'a SE) -> Result<SE2, Err>,
+ mut visit_subexpr: impl FnMut(&'a SE) -> Result<SE2, Err>,
+ mut visit_under_binder: impl FnMut(&'a Label, &'a SE) -> Result<SE2, Err>,
) -> Result<ExprKind<SE2, E>, Err>
where
E: Clone,
{
- visitor::TraverseRefWithBindersVisitor {
- visit_subexpr,
- visit_under_binder,
- }
- .visit(self)
+ self.traverse_ref_maybe_binder(|l, x| match l {
+ None => visit_subexpr(x),
+ Some(l) => visit_under_binder(l, x),
+ })
}
- fn traverse_ref<'a, SE2, Err>(
+ pub(crate) fn traverse_ref<'a, SE2, Err>(
&'a self,
- visit_subexpr: impl FnMut(&'a SE) -> Result<SE2, Err>,
+ mut visit_subexpr: impl FnMut(&'a SE) -> Result<SE2, Err>,
) -> Result<ExprKind<SE2, E>, Err>
where
E: Clone,
{
- visitor::TraverseRefVisitor { visit_subexpr }.visit(self)
+ self.traverse_ref_maybe_binder(|_, e| visit_subexpr(e))
}
fn traverse_mut<'a, Err>(
@@ -206,6 +215,16 @@ impl<SE, E> ExprKind<SE, E> {
visitor::TraverseMutVisitor { visit_subexpr }.visit(self)
}
+ pub fn map_ref_maybe_binder<'a, SE2>(
+ &'a self,
+ mut map: impl FnMut(Option<&'a Label>, &'a SE) -> SE2,
+ ) -> ExprKind<SE2, E>
+ where
+ E: Clone,
+ {
+ trivial_result(self.traverse_ref_maybe_binder(|l, x| Ok(map(l, x))))
+ }
+
pub fn map_ref_with_special_handling_of_binders<'a, SE2>(
&'a self,
mut map_subexpr: impl FnMut(&'a SE) -> SE2,
@@ -214,10 +233,10 @@ impl<SE, E> ExprKind<SE, E> {
where
E: Clone,
{
- trivial_result(self.traverse_ref_with_special_handling_of_binders(
- |x| Ok(map_subexpr(x)),
- |l, x| Ok(map_under_binder(l, x)),
- ))
+ self.map_ref_maybe_binder(|l, x| match l {
+ None => map_subexpr(x),
+ Some(l) => map_under_binder(l, x),
+ })
}
pub fn map_ref<'a, SE2>(
@@ -227,7 +246,7 @@ impl<SE, E> ExprKind<SE, E> {
where
E: Clone,
{
- trivial_result(self.traverse_ref(|x| Ok(map_subexpr(x))))
+ self.map_ref_maybe_binder(|_, e| map_subexpr(e))
}
pub fn map_mut<'a>(&'a mut self, mut map_subexpr: impl FnMut(&'a mut SE)) {
@@ -295,22 +314,6 @@ impl<E> Expr<E> {
}
}
-impl<Label: PartialEq + Clone> V<Label> {
- pub fn shift(&self, delta: isize, var: &V<Label>) -> Option<Self> {
- let V(x, n) = var;
- let V(y, m) = self;
- Some(if x == y && n <= m {
- V(y.clone(), add_ui(*m, delta)?)
- } else {
- V(y.clone(), *m)
- })
- }
-
- pub fn over_binder(&self, x: &Label) -> Option<Self> {
- self.shift(-1, &V(x.clone(), 0))
- }
-}
-
pub fn trivial_result<T>(x: Result<T, !>) -> T {
match x {
Ok(x) => x,
@@ -318,16 +321,6 @@ pub fn trivial_result<T>(x: Result<T, !>) -> T {
}
}
-/// Add an isize to an usize
-/// Returns `None` on over/underflow
-fn add_ui(u: usize, i: isize) -> Option<usize> {
- Some(if i < 0 {
- u.checked_sub(i.checked_neg()? as usize)?
- } else {
- u.checked_add(i as usize)?
- })
-}
-
impl PartialEq for NaiveDouble {
fn eq(&self, other: &Self) -> bool {
self.0.to_bits() == other.0.to_bits()
@@ -357,9 +350,8 @@ impl From<NaiveDouble> for f64 {
}
}
-/// This is only for the specific `Label` type, not generic
-impl From<Label> for V<Label> {
- fn from(x: Label) -> V<Label> {
+impl From<Label> for V {
+ fn from(x: Label) -> V {
V(x, 0)
}
}
diff --git a/dhall/src/syntax/ast/visitor.rs b/dhall/src/syntax/ast/visitor.rs
index 424048b..6a1ce7d 100644
--- a/dhall/src/syntax/ast/visitor.rs
+++ b/dhall/src/syntax/ast/visitor.rs
@@ -1,6 +1,7 @@
-use crate::syntax::*;
use std::iter::FromIterator;
+use crate::syntax::*;
+
/// 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
@@ -295,51 +296,26 @@ where
Ok(())
}
-pub struct TraverseRefWithBindersVisitor<F1, F2> {
- pub visit_subexpr: F1,
- pub visit_under_binder: F2,
-}
+pub struct TraverseRefMaybeBinderVisitor<F>(pub F);
-impl<'a, SE, E, SE2, Err, F1, F2> ExprKindVisitor<'a, SE, SE2, E, E>
- for TraverseRefWithBindersVisitor<F1, F2>
+impl<'a, SE, E, SE2, Err, F> ExprKindVisitor<'a, SE, SE2, E, E>
+ for TraverseRefMaybeBinderVisitor<F>
where
SE: 'a,
E: 'a + Clone,
- F1: FnMut(&'a SE) -> Result<SE2, Err>,
- F2: FnOnce(&'a Label, &'a SE) -> Result<SE2, Err>,
+ F: FnMut(Option<&'a Label>, &'a SE) -> Result<SE2, Err>,
{
type Error = Err;
fn visit_subexpr(&mut self, subexpr: &'a SE) -> Result<SE2, Self::Error> {
- (self.visit_subexpr)(subexpr)
+ (self.0)(None, subexpr)
}
fn visit_subexpr_under_binder(
- self,
+ mut self,
label: &'a Label,
subexpr: &'a SE,
) -> Result<SE2, Self::Error> {
- (self.visit_under_binder)(label, subexpr)
- }
- fn visit_embed(self, embed: &'a E) -> Result<E, Self::Error> {
- Ok(embed.clone())
- }
-}
-
-pub struct TraverseRefVisitor<F1> {
- pub visit_subexpr: F1,
-}
-
-impl<'a, SE, E, SE2, Err, F1> ExprKindVisitor<'a, SE, SE2, E, E>
- for TraverseRefVisitor<F1>
-where
- SE: 'a,
- E: 'a + Clone,
- F1: FnMut(&'a SE) -> Result<SE2, Err>,
-{
- type Error = Err;
-
- fn visit_subexpr(&mut self, subexpr: &'a SE) -> Result<SE2, Self::Error> {
- (self.visit_subexpr)(subexpr)
+ (self.0)(Some(label), subexpr)
}
fn visit_embed(self, embed: &'a E) -> Result<E, Self::Error> {
Ok(embed.clone())
diff --git a/dhall/src/syntax/binary/decode.rs b/dhall/src/syntax/binary/decode.rs
index c18deb5..52b699c 100644
--- a/dhall/src/syntax/binary/decode.rs
+++ b/dhall/src/syntax/binary/decode.rs
@@ -3,13 +3,13 @@ use serde_cbor::value::value as cbor;
use std::iter::FromIterator;
use crate::error::DecodeError;
-use crate::semantics::phase::DecodedExpr;
use crate::syntax;
use crate::syntax::{
Expr, ExprKind, FilePath, FilePrefix, Hash, ImportLocation, ImportMode,
Integer, InterpolatedText, Label, Natural, Scheme, Span, UnspannedExpr,
URL, V,
};
+use crate::DecodedExpr;
pub(crate) fn decode(data: &[u8]) -> Result<DecodedExpr, DecodeError> {
match serde_cbor::de::from_slice(data) {
diff --git a/dhall/src/syntax/text/dhall.abnf b/dhall/src/syntax/text/dhall.abnf
new file mode 120000
index 0000000..4a95034
--- /dev/null
+++ b/dhall/src/syntax/text/dhall.abnf
@@ -0,0 +1 @@
+../../../../dhall-lang/standard/dhall.abnf \ No newline at end of file
diff --git a/dhall/src/dhall.pest.visibility b/dhall/src/syntax/text/dhall.pest.visibility
index 03a000b..03a000b 100644
--- a/dhall/src/dhall.pest.visibility
+++ b/dhall/src/syntax/text/dhall.pest.visibility
diff --git a/dhall/src/syntax/text/parser.rs b/dhall/src/syntax/text/parser.rs
index ef1471f..2ec63e2 100644
--- a/dhall/src/syntax/text/parser.rs
+++ b/dhall/src/syntax/text/parser.rs
@@ -5,7 +5,6 @@ use std::rc::Rc;
use pest_consume::{match_nodes, Parser};
-use crate::semantics::phase::Normalized;
use crate::syntax;
use crate::syntax::map::{DupTreeMap, DupTreeSet};
use crate::syntax::ExprKind::*;
@@ -14,6 +13,7 @@ use crate::syntax::{
InterpolatedText, InterpolatedTextContents, Label, NaiveDouble, Natural,
Scheme, Span, UnspannedExpr, URL, V,
};
+use crate::Normalized;
// This file consumes the parse tree generated by pest and turns it into
// our own AST. All those custom macros should eventually moved into
@@ -422,7 +422,7 @@ impl DhallParser {
))
}
- fn variable(input: ParseInput) -> ParseResult<V<Label>> {
+ fn variable(input: ParseInput) -> ParseResult<V> {
Ok(match_nodes!(input.into_children();
[label(l), natural_literal(idx)] => V(l, idx),
[label(l)] => V(l, 0),
diff --git a/dhall/src/syntax/text/printer.rs b/dhall/src/syntax/text/printer.rs
index 96f4c2a..06dd70f 100644
--- a/dhall/src/syntax/text/printer.rs
+++ b/dhall/src/syntax/text/printer.rs
@@ -496,7 +496,7 @@ impl Display for Scheme {
}
}
-impl<Label: Display> Display for V<Label> {
+impl Display for V {
fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
let V(x, n) = self;
x.fmt(f)?;
generated by cgit v1.2.3 (git 2.25.1) at 2025-01-12 18:22:57 +0000