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-rw-r--r--dhall_core/src/core.rs71
-rw-r--r--dhall_normalize/src/normalize.rs178
2 files changed, 107 insertions, 142 deletions
diff --git a/dhall_core/src/core.rs b/dhall_core/src/core.rs
index 6795c2c..675345e 100644
--- a/dhall_core/src/core.rs
+++ b/dhall_core/src/core.rs
@@ -231,6 +231,17 @@ impl<'i, S, A> From<Builtin> for Expr<'i, S, A> {
}
impl<'i, S, A> Expr<'i, S, A> {
+ pub fn map_shallow<T, F1, F2>(&self, map_expr: F1, map_note: F2) -> Expr<'i, T, A>
+ where
+ A: Clone,
+ T: Clone,
+ S: Clone,
+ F1: Fn(&Self) -> Expr<'i, T, A>,
+ F2: FnOnce(&S) -> T,
+ {
+ map_shallow(self, map_expr, map_note)
+ }
+
pub fn bool_lit(&self) -> Option<bool> {
match *self {
Expr::BoolLit(v) => Some(v),
@@ -628,16 +639,71 @@ fn add_ui(u: usize, i: isize) -> usize {
}
}
-pub fn map_record_value<'a, I, K, V, U, F>(it: I, f: F) -> BTreeMap<K, U>
+pub fn map_shallow<'i, S, T, A, F1, F2>(e: &Expr<'i, S, A>, map: F1, map_note: F2) -> Expr<'i, T, A>
+where
+ A: Clone,
+ S: Clone,
+ T: Clone,
+ F1: Fn(&Expr<'i, S, A>) -> Expr<'i, T, A>,
+ F2: FnOnce(&S) -> T,
+{
+ use crate::Expr::*;
+ let bxmap = |x: &Expr<'i, S, A>| -> Box<Expr<'i, T, A>> { bx(map(x)) };
+ let opt = |x| map_opt_box(x, &map);
+ match *e {
+ Const(k) => Const(k),
+ Var(v) => Var(v),
+ Lam(x, ref t, ref b) => Lam(x, bxmap(t), bxmap(b)),
+ Pi(x, ref t, ref b) => Pi(x, bxmap(t), bxmap(b)),
+ App(ref f, ref a) => App(bxmap(f), bxmap(a)),
+ Let(l, ref t, ref a, ref b) => Let(l, opt(t), bxmap(a), bxmap(b)),
+ Annot(ref x, ref t) => Annot(bxmap(x), bxmap(t)),
+ Builtin(v) => Builtin(v),
+ BoolLit(b) => BoolLit(b),
+ BoolIf(ref b, ref t, ref f) => BoolIf(bxmap(b), bxmap(t), bxmap(f)),
+ NaturalLit(n) => NaturalLit(n),
+ IntegerLit(n) => IntegerLit(n),
+ DoubleLit(n) => DoubleLit(n),
+ TextLit(ref t) => TextLit(t.clone()),
+ BinOp(o, ref x, ref y) => BinOp(o, bxmap(x), bxmap(y)),
+ ListLit(ref t, ref es) => {
+ let es = es.iter().map(&map).collect();
+ ListLit(opt(t), es)
+ }
+ OptionalLit(ref t, ref es) => {
+ let es = es.iter().map(&map).collect();
+ OptionalLit(opt(t), es)
+ }
+ Record(ref kts) => Record(map_record_value(kts, map)),
+ RecordLit(ref kvs) => RecordLit(map_record_value(kvs, map)),
+ Union(ref kts) => Union(map_record_value(kts, map)),
+ UnionLit(k, ref v, ref kvs) => {
+ UnionLit(k, bxmap(v), map_record_value(kvs, map))
+ }
+ Merge(ref x, ref y, ref t) => Merge(bxmap(x), bxmap(y), opt(t)),
+ Field(ref r, x) => Field(bxmap(r), x),
+ Note(ref n, ref e) => Note(map_note(n), bxmap(e)),
+ Embed(ref a) => Embed(a.clone()),
+ }
+}
+
+pub fn map_record_value<'a, I, K, V, U, F>(it: I, mut f: F) -> BTreeMap<K, U>
where
I: IntoIterator<Item = (&'a K, &'a V)>,
K: Eq + Ord + Copy + 'a,
V: 'a,
- F: Fn(&V) -> U,
+ F: FnMut(&V) -> U,
{
it.into_iter().map(|(&k, v)| (k, f(v))).collect()
}
+pub fn map_opt_box<T, U, F>(x: &Option<Box<T>>, f: F) -> Option<Box<U>>
+where
+ F: FnOnce(&T) -> U,
+{
+ x.as_ref().map(|x| x.as_ref()).map(f).map(bx)
+}
+
fn map_op2<T, U, V, F, G>(f: F, g: G, a: T, b: T) -> V
where
F: FnOnce(U, U) -> V,
@@ -916,4 +982,3 @@ where
{
map_op2(f, |x| bx(subst(v, e, x)), a, b)
}
-
diff --git a/dhall_normalize/src/normalize.rs b/dhall_normalize/src/normalize.rs
index 2068ae3..0e46ee0 100644
--- a/dhall_normalize/src/normalize.rs
+++ b/dhall_normalize/src/normalize.rs
@@ -1,7 +1,7 @@
#![allow(non_snake_case)]
-use std::fmt;
use dhall_core::core::*;
use dhall_generator::dhall;
+use std::fmt;
/// Reduce an expression to its normal form, performing beta reduction
///
@@ -22,18 +22,20 @@ where
use dhall_core::Builtin::*;
use dhall_core::Expr::*;
match *e {
- Const(k) => Const(k),
- Var(v) => Var(v),
- Lam(x, ref tA, ref b) => {
- let tA2 = normalize(tA);
- let b2 = normalize(b);
- Lam(x, bx(tA2), bx(b2))
- }
- Pi(x, ref tA, ref tB) => {
- let tA2 = normalize(tA);
- let tB2 = normalize(tB);
- pi(x, tA2, tB2)
+ // Matches that don't normalize everything right away
+ Let(f, _, ref r, ref b) => {
+ let r2 = shift::<_, S, _>(1, V(f, 0), r);
+ let b2 = subst(V(f, 0), &r2, b);
+ let b3 = shift::<_, T, _>(-1, V(f, 0), &b2);
+ normalize(&b3)
}
+ BoolIf(ref b, ref t, ref f) => match normalize(b) {
+ BoolLit(true) => normalize(t),
+ BoolLit(false) => normalize(f),
+ b2 => BoolIf(bx(b2), bx(normalize(t)), bx(normalize(f))),
+ },
+ Annot(ref x, _) => normalize(x),
+ Note(_, ref e) => normalize(e),
App(ref f, ref a) => match normalize::<S, T, A>(f) {
Lam(x, _A, b) => {
// Beta reduce
@@ -144,135 +146,33 @@ where
(f2, a2) => app(f2, a2),
},
},
- Let(f, _, ref r, ref b) => {
- let r2 = shift::<_, S, _>(1, V(f, 0), r);
- let b2 = subst(V(f, 0), &r2, b);
- let b3 = shift::<_, T, _>(-1, V(f, 0), &b2);
- normalize(&b3)
- }
- Annot(ref x, _) => normalize(x),
- Builtin(v) => Builtin(v),
- BoolLit(b) => BoolLit(b),
- BinOp(BoolAnd, ref x, ref y) => with_binop(
- BoolAnd,
- Expr::bool_lit,
- |xn, yn| BoolLit(xn && yn),
- normalize(x),
- normalize(y),
- ),
- BinOp(BoolOr, ref x, ref y) => with_binop(
- BoolOr,
- Expr::bool_lit,
- |xn, yn| BoolLit(xn || yn),
- normalize(x),
- normalize(y),
- ),
- BinOp(BoolEQ, ref x, ref y) => with_binop(
- BoolEQ,
- Expr::bool_lit,
- |xn, yn| BoolLit(xn == yn),
- normalize(x),
- normalize(y),
- ),
- BinOp(BoolNE, ref x, ref y) => with_binop(
- BoolNE,
- Expr::bool_lit,
- |xn, yn| BoolLit(xn != yn),
- normalize(x),
- normalize(y),
- ),
- BoolIf(ref b, ref t, ref f) => match normalize(b) {
- BoolLit(true) => normalize(t),
- BoolLit(false) => normalize(f),
- b2 => BoolIf(bx(b2), bx(normalize(t)), bx(normalize(f))),
- },
- NaturalLit(n) => NaturalLit(n),
- BinOp(NaturalPlus, ref x, ref y) => with_binop(
- NaturalPlus,
- Expr::natural_lit,
- |xn, yn| NaturalLit(xn + yn),
- normalize(x),
- normalize(y),
- ),
- BinOp(NaturalTimes, ref x, ref y) => with_binop(
- NaturalTimes,
- Expr::natural_lit,
- |xn, yn| NaturalLit(xn * yn),
- normalize(x),
- normalize(y),
- ),
- IntegerLit(n) => IntegerLit(n),
- DoubleLit(n) => DoubleLit(n),
- TextLit(ref t) => TextLit(t.clone()),
- BinOp(TextAppend, ref x, ref y) => with_binop(
- TextAppend,
- Expr::text_lit,
- |xt, yt| TextLit(xt + &yt),
- normalize(x),
- normalize(y),
- ),
- BinOp(ListAppend, ref x, ref y) => {
- match (normalize(x), normalize(y)) {
- (ListLit(t1, xs), ListLit(t2, ys)) => {
- // Drop type annotation if the result is not empty
- let t = if xs.len() == 0 && ys.len() == 0 {
- t1.or(t2)
- } else {
- None
- };
- let xs = xs.into_iter();
- let ys = ys.into_iter();
- ListLit(t, xs.chain(ys).collect())
- }
- (x, y) => BinOp(ListAppend, bx(x), bx(y)),
+
+ // Normalize everything else before matching
+ ref e => match e.map_shallow(normalize, |_| unreachable!()) {
+ BinOp(BoolAnd, box BoolLit(x), box BoolLit(y)) => BoolLit(x && y),
+ BinOp(BoolOr, box BoolLit(x), box BoolLit(y)) => BoolLit(x || y),
+ BinOp(BoolEQ, box BoolLit(x), box BoolLit(y)) => BoolLit(x == y),
+ BinOp(BoolNE, box BoolLit(x), box BoolLit(y)) => BoolLit(x != y),
+ BinOp(NaturalPlus, box NaturalLit(x), box NaturalLit(y)) => NaturalLit(x + y),
+ BinOp(NaturalTimes, box NaturalLit(x), box NaturalLit(y)) => NaturalLit(x * y),
+ BinOp(TextAppend, box TextLit(x), box TextLit(y)) => TextLit(x + &y),
+ BinOp(ListAppend, box ListLit(t1, xs), box ListLit(t2, ys)) => {
+ // Drop type annotation if the result is nonempty
+ let t = if xs.len() == 0 && ys.len() == 0 {
+ t1.or(t2)
+ } else {
+ None
+ };
+ let xs = xs.into_iter();
+ let ys = ys.into_iter();
+ ListLit(t, xs.chain(ys).collect())
}
- },
- ListLit(ref t, ref es) => {
- let t2 = t.as_ref().map(|x| x.as_ref()).map(normalize).map(bx);
- let es2 = es.iter().map(normalize).collect();
- ListLit(t2, es2)
- }
- OptionalLit(ref t, ref es) => {
- let t2 = t.as_ref().map(|x| x.as_ref()).map(normalize).map(bx);
- let es2 = es.iter().map(normalize).collect();
- OptionalLit(t2, es2)
- }
- Record(ref kts) => Record(map_record_value(kts, normalize)),
- RecordLit(ref kvs) => RecordLit(map_record_value(kvs, normalize)),
- Union(ref kts) => Union(map_record_value(kts, normalize)),
- UnionLit(k, ref v, ref kvs) => {
- UnionLit(k, bx(normalize(v)), map_record_value(kvs, normalize))
- }
- Merge(ref _x, ref _y, ref _t) => unimplemented!(),
- Field(ref r, x) => match normalize(r) {
- RecordLit(kvs) => match kvs.get(x) {
- Some(r2) => normalize(r2),
- None => {
- Field(bx(RecordLit(map_record_value(&kvs, normalize))), x)
- }
+ Merge(_x, _y, _t) => unimplemented!(),
+ Field(box RecordLit(kvs), x) => match kvs.get(x) {
+ Some(r) => r.clone(),
+ None => Field(bx(RecordLit(kvs)), x),
},
- r2 => Field(bx(r2), x),
+ e => e,
},
- Note(_, ref e) => normalize(e),
- Embed(ref a) => Embed(a.clone()),
- ref e => unimplemented!("{:?}", e),
- }
-}
-
-fn with_binop<'a, S, A, U, Get, Set>(
- op: BinOp,
- get: Get,
- set: Set,
- x: Expr<'a, S, A>,
- y: Expr<'a, S, A>,
-) -> Expr<'a, S, A>
-where
- Get: Fn(&Expr<'a, S, A>) -> Option<U>,
- Set: FnOnce(U, U) -> Expr<'a, S, A>,
-{
- if let (Some(xv), Some(yv)) = (get(&x), get(&y)) {
- set(xv, yv)
- } else {
- Expr::BinOp(op, bx(x), bx(y))
}
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-26 20:14:03 +0000