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authorNadrieril2019-04-14 14:17:15 +0200
committerNadrieril2019-04-14 14:17:15 +0200
commit6d6626b79710d11d1de4a8c479b67287e758df59 (patch)
tree49a28e9ddde7ee6768e88c7aec944c20804f7353
parentd53893de0b45bbe56b3e5825ba6e979485cc1d75 (diff)
Rewrite map methods with Visitor traits
Closes #69
Diffstat (limited to '')
-rw-r--r--dhall_core/src/core.rs144
-rw-r--r--dhall_core/src/lib.rs1
-rw-r--r--dhall_core/src/visitor.rs226
3 files changed, 261 insertions, 110 deletions
diff --git a/dhall_core/src/core.rs b/dhall_core/src/core.rs
index 1de363c..fe53bb2 100644
--- a/dhall_core/src/core.rs
+++ b/dhall_core/src/core.rs
@@ -1,8 +1,10 @@
#![allow(non_snake_case)]
-use crate::*;
use std::collections::BTreeMap;
use std::rc::Rc;
+use crate::visitor::{TraverseRefSimpleVisitor, TraverseRefVisitor};
+use crate::*;
+
pub type Integer = isize;
pub type Natural = usize;
pub type Double = NaiveDouble;
@@ -209,8 +211,8 @@ impl<S, A> Expr<S, A> {
T: Clone,
S: Clone,
F1: Fn(&Self) -> Expr<T, B>,
- F2: FnOnce(&S) -> T,
- F3: FnOnce(&A) -> B,
+ F2: Fn(&S) -> T,
+ F3: Fn(&A) -> B,
F4: Fn(&Label) -> Label,
{
self.map_ref(
@@ -340,13 +342,13 @@ impl<SE, L, N, E> ExprF<SE, L, N, E> {
}
}
- fn traverse_ref<'a, SE2, L2, N2, E2, Err, F1, F2, F3, F4, F5>(
+ pub fn traverse_ref<'a, SE2, L2, N2, E2, Err, F1, F2, F3, F4, F5>(
&'a self,
- map_subexpr: F1,
- map_under_binder: F2,
- map_note: F3,
- map_embed: F4,
- mut map_label: F5,
+ visit_subexpr: F1,
+ visit_under_binder: F2,
+ visit_note: F3,
+ visit_embed: F4,
+ visit_label: F5,
) -> Result<ExprF<SE2, L2, N2, E2>, Err>
where
L: Ord,
@@ -357,95 +359,30 @@ impl<SE, L, N, E> ExprF<SE, L, N, E> {
F4: FnOnce(&'a E) -> Result<E2, Err>,
F5: FnMut(&'a L) -> Result<L2, Err>,
{
- let mut map = map_subexpr;
- fn vec<'a, T, U, Err, F: FnMut(&'a T) -> Result<U, Err>>(
- x: &'a Vec<T>,
- f: F,
- ) -> Result<Vec<U>, Err> {
- x.iter().map(f).collect()
- }
- fn opt<'a, T, U, Err, F: FnOnce(&'a T) -> Result<U, Err>>(
- x: &'a Option<T>,
- f: F,
- ) -> Result<Option<U>, Err> {
- Ok(match x {
- Some(x) => Some(f(x)?),
- None => None,
- })
- }
- fn btmap<'a, K, L, T, U, Err, FK, FV>(
- x: &'a BTreeMap<K, T>,
- mut fk: FK,
- mut fv: FV,
- ) -> Result<BTreeMap<L, U>, Err>
- where
- K: Ord,
- L: Ord,
- FK: FnMut(&'a K) -> Result<L, Err>,
- FV: FnMut(&'a T) -> Result<U, Err>,
- {
- x.into_iter().map(|(k, v)| Ok((fk(k)?, fv(v)?))).collect()
- }
-
- use crate::ExprF::*;
- Ok(match self {
- Var(V(l, n)) => Var(V(map_label(l)?, *n)),
- Lam(l, t, b) => {
- let b = map_under_binder(&l, b)?;
- Lam(map_label(l)?, map(t)?, b)
- }
- Pi(l, t, b) => {
- let b = map_under_binder(&l, b)?;
- Pi(map_label(l)?, map(t)?, b)
- }
- Let(l, t, a, b) => {
- let b = map_under_binder(&l, b)?;
- Let(map_label(l)?, opt(t, &mut map)?, map(a)?, b)
- }
- App(f, args) => App(map(f)?, vec(args, map)?),
- Annot(x, t) => Annot(map(x)?, map(t)?),
- Const(k) => Const(*k),
- Builtin(v) => Builtin(*v),
- BoolLit(b) => BoolLit(*b),
- NaturalLit(n) => NaturalLit(*n),
- IntegerLit(n) => IntegerLit(*n),
- DoubleLit(n) => DoubleLit(*n),
- TextLit(t) => TextLit(t.traverse_ref(map)?),
- BinOp(o, x, y) => BinOp(*o, map(x)?, map(y)?),
- BoolIf(b, t, f) => BoolIf(map(b)?, map(t)?, map(f)?),
- EmptyListLit(t) => EmptyListLit(map(t)?),
- NEListLit(es) => NEListLit(vec(es, map)?),
- EmptyOptionalLit(t) => EmptyOptionalLit(map(t)?),
- NEOptionalLit(e) => NEOptionalLit(map(e)?),
- RecordType(kts) => RecordType(btmap(kts, map_label, map)?),
- RecordLit(kvs) => RecordLit(btmap(kvs, map_label, map)?),
- UnionType(kts) => UnionType(btmap(kts, map_label, map)?),
- UnionLit(k, v, kvs) => {
- UnionLit(map_label(k)?, map(v)?, btmap(kvs, map_label, map)?)
- }
- Merge(x, y, t) => Merge(map(x)?, map(y)?, opt(t, map)?),
- Field(e, l) => Field(map(e)?, map_label(l)?),
- Projection(e, ls) => Projection(map(e)?, vec(ls, map_label)?),
- Note(n, e) => Note(map_note(n)?, map(e)?),
- Embed(a) => Embed(map_embed(a)?),
+ self.visit(TraverseRefVisitor {
+ visit_subexpr,
+ visit_under_binder,
+ visit_note,
+ visit_embed,
+ visit_label,
})
}
pub fn map_ref<'a, SE2, L2, N2, E2, F1, F2, F3, F4, F5>(
&'a self,
mut map_subexpr: F1,
- map_under_binder: F2,
- map_note: F3,
- map_embed: F4,
+ mut map_under_binder: F2,
+ mut map_note: F3,
+ mut map_embed: F4,
mut map_label: F5,
) -> ExprF<SE2, L2, N2, E2>
where
L: Ord,
L2: Ord,
F1: FnMut(&'a SE) -> SE2,
- F2: FnOnce(&'a L, &'a SE) -> SE2,
- F3: FnOnce(&'a N) -> N2,
- F4: FnOnce(&'a E) -> E2,
+ F2: FnMut(&'a L, &'a SE) -> SE2,
+ F3: FnMut(&'a N) -> N2,
+ F4: FnMut(&'a E) -> E2,
F5: FnMut(&'a L) -> L2,
{
trivial_result(self.traverse_ref(
@@ -457,44 +394,31 @@ impl<SE, L, N, E> ExprF<SE, L, N, E> {
))
}
- pub fn map_ref_simple<'a, SE2, F1>(
+ pub fn traverse_ref_simple<'a, SE2, Err, F1>(
&'a self,
- map_subexpr: F1,
- ) -> ExprF<SE2, L, N, E>
+ visit_subexpr: F1,
+ ) -> Result<ExprF<SE2, L, N, E>, Err>
where
- L: Ord,
- L: Clone,
+ L: Ord + Clone,
N: Clone,
E: Clone,
- F1: Fn(&'a SE) -> SE2,
+ F1: FnMut(&'a SE) -> Result<SE2, Err>,
{
- self.map_ref(
- &map_subexpr,
- |_, e| map_subexpr(e),
- N::clone,
- E::clone,
- L::clone,
- )
+ self.visit(TraverseRefSimpleVisitor { visit_subexpr })
}
- pub fn traverse_ref_simple<'a, SE2, Err, F1>(
+ pub fn map_ref_simple<'a, SE2, F1>(
&'a self,
map_subexpr: F1,
- ) -> Result<ExprF<SE2, L, N, E>, Err>
+ ) -> ExprF<SE2, L, N, E>
where
L: Ord,
L: Clone,
N: Clone,
E: Clone,
- F1: Fn(&'a SE) -> Result<SE2, Err>,
+ F1: Fn(&'a SE) -> SE2,
{
- self.traverse_ref(
- &map_subexpr,
- |_, e| map_subexpr(e),
- |x| Ok(N::clone(x)),
- |x| Ok(E::clone(x)),
- |x| Ok(L::clone(x)),
- )
+ trivial_result(self.traverse_ref_simple(|x| Ok(map_subexpr(x))))
}
// pub fn zip<SE2, L2, N2, E2>(
@@ -552,7 +476,7 @@ impl<N, E> SubExpr<N, E> {
) -> Self
where
F1: FnMut(&'a Self) -> Self,
- F2: FnOnce(&'a Label, &'a Self) -> Self,
+ F2: FnMut(&'a Label, &'a Self) -> Self,
{
match self.as_ref() {
ExprF::Embed(_) => SubExpr::clone(self),
diff --git a/dhall_core/src/lib.rs b/dhall_core/src/lib.rs
index 887f29e..62c0ecd 100644
--- a/dhall_core/src/lib.rs
+++ b/dhall_core/src/lib.rs
@@ -20,3 +20,4 @@ pub use crate::printer::*;
mod parser;
pub use crate::parser::*;
pub mod context;
+pub mod visitor;
diff --git a/dhall_core/src/visitor.rs b/dhall_core/src/visitor.rs
new file mode 100644
index 0000000..1b50e46
--- /dev/null
+++ b/dhall_core/src/visitor.rs
@@ -0,0 +1,226 @@
+use std::collections::BTreeMap;
+
+use crate::*;
+
+pub trait ExprVisitor<'a, SE1, SE2, L1, L2, N1, N2, 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_note(self, note: &'a N1) -> Result<N2, Self::Error>;
+ fn visit_embed(self, embed: &'a E1) -> Result<E2, Self::Error>;
+
+ fn visit_subexpr_under_binder(
+ mut self,
+ _label: &'a L1,
+ 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, N2, E2>, Self::Error> {
+ Ok(ExprF::Embed(self.visit_embed(embed)?))
+ }
+
+ fn visit_note_squash(
+ mut self,
+ note: &'a N1,
+ subexpr: &'a SE1,
+ ) -> Result<ExprF<SE2, L2, N2, E2>, Self::Error> {
+ let subexpr = self.visit_subexpr(subexpr)?;
+ let note = self.visit_note(note)?;
+ Ok(ExprF::Note(note, subexpr))
+ }
+}
+
+impl<SE, L, N, E> ExprF<SE, L, N, E> {
+ pub fn visit<'a, V, SE2, L2, N2, E2>(
+ &'a self,
+ mut v: V,
+ ) -> Result<ExprF<SE2, L2, N2, E2>, V::Error>
+ where
+ L: Ord,
+ L2: Ord,
+ V: ExprVisitor<'a, SE, SE2, L, L2, N, N2, E, E2>,
+ {
+ fn vec<'a, T, U, Err, F: FnMut(&'a T) -> Result<U, Err>>(
+ x: &'a Vec<T>,
+ f: F,
+ ) -> Result<Vec<U>, Err> {
+ x.iter().map(f).collect()
+ }
+ fn opt<'a, T, U, Err, F: FnOnce(&'a T) -> Result<U, Err>>(
+ x: &'a Option<T>,
+ f: F,
+ ) -> Result<Option<U>, Err> {
+ Ok(match x {
+ Some(x) => Some(f(x)?),
+ None => None,
+ })
+ }
+ fn btmap<'a, V, SE, L, N, E, SE2, L2, N2, E2>(
+ x: &'a BTreeMap<L, SE>,
+ mut v: V,
+ ) -> Result<BTreeMap<L2, SE2>, V::Error>
+ where
+ L: Ord,
+ L2: Ord,
+ V: ExprVisitor<'a, SE, SE2, L, L2, N, N2, E, E2>,
+ {
+ x.into_iter()
+ .map(|(k, x)| Ok((v.visit_label(k)?, v.visit_subexpr(x)?)))
+ .collect()
+ }
+
+ use crate::ExprF::*;
+ Ok(match self {
+ Var(V(l, n)) => Var(V(v.visit_label(l)?, *n)),
+ Lam(l, t, e) => {
+ let t = v.visit_subexpr(t)?;
+ let (l, e) = v.visit_binder(l, e)?;
+ Lam(l, 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(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)
+ }
+ App(f, args) => {
+ App(v.visit_subexpr(f)?, vec(args, |e| v.visit_subexpr(e))?)
+ }
+ Annot(x, t) => Annot(v.visit_subexpr(x)?, v.visit_subexpr(t)?),
+ Const(k) => Const(*k),
+ Builtin(v) => Builtin(*v),
+ BoolLit(b) => BoolLit(*b),
+ NaturalLit(n) => NaturalLit(*n),
+ IntegerLit(n) => IntegerLit(*n),
+ DoubleLit(n) => DoubleLit(*n),
+ TextLit(t) => TextLit(t.traverse_ref(|e| v.visit_subexpr(e))?),
+ BinOp(o, x, y) => {
+ BinOp(*o, v.visit_subexpr(x)?, v.visit_subexpr(y)?)
+ }
+ BoolIf(b, t, f) => BoolIf(
+ v.visit_subexpr(b)?,
+ v.visit_subexpr(t)?,
+ v.visit_subexpr(f)?,
+ ),
+ EmptyListLit(t) => EmptyListLit(v.visit_subexpr(t)?),
+ NEListLit(es) => NEListLit(vec(es, |e| v.visit_subexpr(e))?),
+ EmptyOptionalLit(t) => EmptyOptionalLit(v.visit_subexpr(t)?),
+ NEOptionalLit(e) => NEOptionalLit(v.visit_subexpr(e)?),
+ RecordType(kts) => RecordType(btmap(kts, v)?),
+ RecordLit(kvs) => RecordLit(btmap(kvs, v)?),
+ UnionType(kts) => UnionType(btmap(kts, v)?),
+ UnionLit(k, x, kvs) => {
+ UnionLit(v.visit_label(k)?, v.visit_subexpr(x)?, btmap(kvs, 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))?)
+ }
+ Note(n, e) => v.visit_note_squash(n, e)?,
+ Embed(a) => v.visit_embed_squash(a)?,
+ })
+ }
+}
+
+pub struct TraverseRefVisitor<F1, F2, F3, F4, F5> {
+ pub visit_subexpr: F1,
+ pub visit_under_binder: F2,
+ pub visit_note: F3,
+ pub visit_embed: F4,
+ pub visit_label: F5,
+}
+
+impl<'a, SE, L, N, E, SE2, L2, N2, E2, Err, F1, F2, F3, F4, F5>
+ ExprVisitor<'a, SE, SE2, L, L2, N, N2, E, E2>
+ for TraverseRefVisitor<F1, F2, F3, F4, F5>
+where
+ SE: 'a,
+ L: 'a,
+ N: 'a,
+ E: 'a,
+ L: Ord,
+ L2: Ord,
+ F1: FnMut(&'a SE) -> Result<SE2, Err>,
+ F2: FnOnce(&'a L, &'a SE) -> Result<SE2, Err>,
+ F3: FnOnce(&'a N) -> Result<N2, Err>,
+ F4: FnOnce(&'a E) -> Result<E2, Err>,
+ F5: FnMut(&'a L) -> Result<L2, Err>,
+{
+ type Error = Err;
+
+ fn visit_subexpr(&mut self, subexpr: &'a SE) -> Result<SE2, Self::Error> {
+ (self.visit_subexpr)(subexpr)
+ }
+ fn visit_subexpr_under_binder(
+ self,
+ label: &'a L,
+ subexpr: &'a SE,
+ ) -> Result<SE2, Self::Error> {
+ (self.visit_under_binder)(label, subexpr)
+ }
+ fn visit_note(self, note: &'a N) -> Result<N2, Self::Error> {
+ (self.visit_note)(note)
+ }
+ 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 TraverseRefSimpleVisitor<F1> {
+ pub visit_subexpr: F1,
+}
+
+impl<'a, SE, L, N, E, SE2, Err, F1> ExprVisitor<'a, SE, SE2, L, L, N, N, E, E>
+ for TraverseRefSimpleVisitor<F1>
+where
+ SE: 'a,
+ L: Ord + Clone + 'a,
+ N: Clone + 'a,
+ E: Clone + 'a,
+ 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)
+ }
+ fn visit_note(self, note: &'a N) -> Result<N, Self::Error> {
+ Ok(N::clone(note))
+ }
+ fn visit_embed(self, embed: &'a E) -> Result<E, Self::Error> {
+ Ok(E::clone(embed))
+ }
+ fn visit_label(&mut self, label: &'a L) -> Result<L, Self::Error> {
+ Ok(L::clone(label))
+ }
+}