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-rw-r--r--dhall/src/normalize.rs180
1 files changed, 69 insertions, 111 deletions
diff --git a/dhall/src/normalize.rs b/dhall/src/normalize.rs
index d02dd80..e88cc7b 100644
--- a/dhall/src/normalize.rs
+++ b/dhall/src/normalize.rs
@@ -1,6 +1,5 @@
#![allow(non_snake_case)]
use std::collections::BTreeMap;
-use std::fmt;
use dhall_core::context::Context;
use dhall_core::*;
@@ -26,59 +25,40 @@ impl<'a> Typed<'a> {
}
}
-fn apply_builtin<N, E>(b: Builtin, args: &[Expr<N, E>]) -> WhatNext<N, E>
-where
- N: fmt::Debug + Clone,
- E: fmt::Debug + Clone,
-{
+fn apply_builtin(b: Builtin, args: &[WHNF]) -> WhatNext<X, X> {
+ let args: Vec<_> = args
+ .iter()
+ .map(|val| val.clone().normalize_to_expr().unroll())
+ .collect();
use dhall_core::Builtin::*;
use dhall_core::ExprF::*;
use WhatNext::*;
- let (ret, rest) = match (b, args) {
- (OptionalNone, [t, rest..]) => (rc(EmptyOptionalLit(t.roll())), rest),
- (NaturalIsZero, [NaturalLit(n), rest..]) => {
- (rc(BoolLit(*n == 0)), rest)
+ let ret = match (b, args.as_slice()) {
+ (OptionalNone, [t]) => rc(EmptyOptionalLit(t.roll())),
+ (NaturalIsZero, [NaturalLit(n)]) => rc(BoolLit(*n == 0)),
+ (NaturalEven, [NaturalLit(n)]) => rc(BoolLit(*n % 2 == 0)),
+ (NaturalOdd, [NaturalLit(n)]) => rc(BoolLit(*n % 2 != 0)),
+ (NaturalToInteger, [NaturalLit(n)]) => rc(IntegerLit(*n as isize)),
+ (NaturalShow, [NaturalLit(n)]) => rc(TextLit(n.to_string().into())),
+ (ListLength, [_, EmptyListLit(_)]) => rc(NaturalLit(0)),
+ (ListLength, [_, NEListLit(ys)]) => rc(NaturalLit(ys.len())),
+ (ListHead, [_, EmptyListLit(t)]) => rc(EmptyOptionalLit(t.clone())),
+ (ListHead, [_, NEListLit(ys)]) => {
+ rc(NEOptionalLit(ys.first().unwrap().clone()))
}
- (NaturalEven, [NaturalLit(n), rest..]) => {
- (rc(BoolLit(*n % 2 == 0)), rest)
+ (ListLast, [_, EmptyListLit(t)]) => rc(EmptyOptionalLit(t.clone())),
+ (ListLast, [_, NEListLit(ys)]) => {
+ rc(NEOptionalLit(ys.last().unwrap().clone()))
}
- (NaturalOdd, [NaturalLit(n), rest..]) => {
- (rc(BoolLit(*n % 2 != 0)), rest)
- }
- (NaturalToInteger, [NaturalLit(n), rest..]) => {
- (rc(IntegerLit(*n as isize)), rest)
- }
- (NaturalShow, [NaturalLit(n), rest..]) => {
- (rc(TextLit(n.to_string().into())), rest)
- }
- (ListLength, [_, EmptyListLit(_), rest..]) => (rc(NaturalLit(0)), rest),
- (ListLength, [_, NEListLit(ys), rest..]) => {
- (rc(NaturalLit(ys.len())), rest)
- }
- (ListHead, [_, EmptyListLit(t), rest..]) => {
- (rc(EmptyOptionalLit(t.clone())), rest)
- }
- (ListHead, [_, NEListLit(ys), rest..]) => {
- (rc(NEOptionalLit(ys.first().unwrap().clone())), rest)
- }
- (ListLast, [_, EmptyListLit(t), rest..]) => {
- (rc(EmptyOptionalLit(t.clone())), rest)
- }
- (ListLast, [_, NEListLit(ys), rest..]) => {
- (rc(NEOptionalLit(ys.last().unwrap().clone())), rest)
- }
- (ListReverse, [_, EmptyListLit(t), rest..]) => {
- (rc(EmptyListLit(t.clone())), rest)
- }
- (ListReverse, [_, NEListLit(ys), rest..]) => {
+ (ListReverse, [_, EmptyListLit(t)]) => rc(EmptyListLit(t.clone())),
+ (ListReverse, [_, NEListLit(ys)]) => {
let ys = ys.iter().rev().cloned().collect();
- (rc(NEListLit(ys)), rest)
+ rc(NEListLit(ys))
}
- (ListIndexed, [_, EmptyListLit(t), rest..]) => (
- dhall::subexpr!([] : List ({ index : Natural, value : t })),
- rest,
- ),
- (ListIndexed, [_, NEListLit(xs), rest..]) => {
+ (ListIndexed, [_, EmptyListLit(t)]) => {
+ dhall::subexpr!([] : List ({ index : Natural, value : t }))
+ }
+ (ListIndexed, [_, NEListLit(xs)]) => {
let xs = xs
.iter()
.cloned()
@@ -88,9 +68,9 @@ where
dhall::subexpr!({ index = i, value = e })
})
.collect();
- (rc(NEListLit(xs)), rest)
+ rc(NEListLit(xs))
}
- (ListBuild, [a0, g, rest..]) => {
+ (ListBuild, [a0, g]) => {
'ret: {
// if let App(f2, args2) = g {
// if let (Builtin(ListFold), [_, x, rest_inner..]) =
@@ -106,18 +86,15 @@ where
let a0 = a0.roll();
let a1 = shift0(1, &"x".into(), &a0);
let g = g.roll();
- break 'ret (
- dhall::subexpr!(
- g
- (List a0)
- (λ(x : a0) -> λ(xs : List a1) -> [ x ] # xs)
- ([] : List a0)
- ),
- rest,
+ break 'ret dhall::subexpr!(
+ g
+ (List a0)
+ (λ(x : a0) -> λ(xs : List a1) -> [ x ] # xs)
+ ([] : List a0)
);
}
}
- (OptionalBuild, [a0, g, rest..]) => {
+ (OptionalBuild, [a0, g]) => {
'ret: {
// if let App(f2, args2) = g {
// if let (Builtin(OptionalFold), [_, x, rest_inner..]) =
@@ -132,75 +109,64 @@ where
// };
let a0 = a0.roll();
let g = g.roll();
- break 'ret (
- dhall::subexpr!(
- g
- (Optional a0)
- (λ(x: a0) -> Some x)
- (None a0)
- ),
- rest,
+ break 'ret dhall::subexpr!(
+ g
+ (Optional a0)
+ (λ(x: a0) -> Some x)
+ (None a0)
);
}
}
- (ListFold, [_, EmptyListLit(_), _, _, nil, rest..]) => {
- (nil.roll(), rest)
- }
- (ListFold, [_, NEListLit(xs), _, cons, nil, rest..]) => (
+ (ListFold, [_, EmptyListLit(_), _, _, nil]) => nil.roll(),
+ (ListFold, [_, NEListLit(xs), _, cons, nil]) => {
xs.iter().rev().fold(nil.roll(), |acc, x| {
let x = x.clone();
let acc = acc.clone();
let cons = cons.roll();
dhall::subexpr!(cons x acc)
- }),
- rest,
- ),
+ })
+ }
// // fold/build fusion
// (ListFold, [_, App(box Builtin(ListBuild), [_, x, rest..]), rest..]) => {
// normalize_whnf(&App(bx(x.clone()), rest.to_vec()))
// }
- (OptionalFold, [_, NEOptionalLit(x), _, just, _, rest..]) => {
+ (OptionalFold, [_, NEOptionalLit(x), _, just, _]) => {
let x = x.clone();
let just = just.roll();
- (dhall::subexpr!(just x), rest)
+ dhall::subexpr!(just x)
}
- (OptionalFold, [_, EmptyOptionalLit(_), _, _, nothing, rest..]) => {
- (nothing.roll(), rest)
+ (OptionalFold, [_, EmptyOptionalLit(_), _, _, nothing]) => {
+ nothing.roll()
}
// // fold/build fusion
// (OptionalFold, [_, App(box Builtin(OptionalBuild), [_, x, rest..]), rest..]) => {
// normalize_whnf(&App(bx(x.clone()), rest.to_vec()))
// }
- (NaturalBuild, [g, rest..]) => {
- 'ret: {
- // if let App(f2, args2) = g {
- // if let (Builtin(NaturalFold), [x, rest_inner..]) =
- // (f2.as_ref(), args2.as_slice())
- // {
- // // fold/build fusion
- // break 'ret (
- // rc(App(x.clone(), rest_inner.to_vec())),
- // rest,
- // );
- // }
- // };
- let g = g.roll();
- break 'ret (
- dhall::subexpr!(g Natural (λ(x : Natural) -> x + 1) 0),
- rest,
- );
- }
- }
- (NaturalFold, [NaturalLit(0), _, _, zero, rest..]) => {
- (zero.roll(), rest)
+ (NaturalBuild, [g]) => {
+ // 'ret: {
+ // if let App(f2, args2) = g {
+ // if let (Builtin(NaturalFold), [x, rest_inner..]) =
+ // (f2.as_ref(), args2.as_slice())
+ // {
+ // // fold/build fusion
+ // break 'ret (
+ // rc(App(x.clone(), rest_inner.to_vec())),
+ // rest,
+ // );
+ // }
+ // };
+ // }
+ let g = g.roll();
+ dhall::subexpr!(g Natural (λ(x : Natural) -> x + 1) 0)
}
- (NaturalFold, [NaturalLit(n), t, succ, zero, rest..]) => {
+ (NaturalFold, [NaturalLit(0), _, _, zero]) => zero.roll(),
+ (NaturalFold, [NaturalLit(n), t, succ, zero]) => {
let fold = rc(Builtin(NaturalFold));
let n = rc(NaturalLit(n - 1));
let t = t.roll();
let succ = succ.roll();
let zero = zero.roll();
- (dhall::subexpr!(succ (fold n t succ zero)), rest)
+ dhall::subexpr!(succ (fold n t succ zero))
}
// (NaturalFold, Some(App(f2, args2)), _) => {
// match (f2.as_ref(), args2.as_slice()) {
@@ -213,11 +179,7 @@ where
// }
_ => return DoneAsIs,
};
- // Put the remaining arguments back and eval again. In most cases
- // ret will not be of a form that can be applied, so this won't go very deep.
- // In lots of cases, there are no remaining args so this cann will just return ret.
- let rest = rest.iter().map(ExprF::roll);
- Continue(rest.fold(ret, |acc, e| rc(ExprF::App(acc, e))).unroll())
+ Continue(ret.unroll())
}
// #[derive(Debug, Clone)]
@@ -403,11 +365,7 @@ impl Closure {
}
Closure::AppliedBuiltin(ctx, b, mut args) => {
args.push(val);
- let args_unrolled: Vec<_> = args
- .iter()
- .map(|val| val.clone().normalize_to_expr().unroll())
- .collect();
- match apply_builtin(b, &args_unrolled).into_value(&ctx) {
+ match apply_builtin(b, &args).into_value(&ctx) {
Some(v) => v,
None => {
WHNF::Closure(Closure::AppliedBuiltin(ctx, b, args))