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-rw-r--r--dhall/src/normalize.rs308
1 files changed, 165 insertions, 143 deletions
diff --git a/dhall/src/normalize.rs b/dhall/src/normalize.rs
index 5749989..1c90c77 100644
--- a/dhall/src/normalize.rs
+++ b/dhall/src/normalize.rs
@@ -59,190 +59,191 @@ impl<'a> Typed<'a> {
}
}
-fn apply_builtin(b: Builtin, args: Vec<Value>) -> Value {
+fn apply_builtin(b: Builtin, args: Vec<Thunk>) -> Value {
use dhall_core::Builtin::*;
use Value::*;
- let ret = match b {
- OptionalNone => improved_slice_patterns::match_vec!(args;
- [t] => EmptyOptionalLit(TypeThunk::from_whnf(t)),
- ),
- NaturalIsZero => improved_slice_patterns::match_vec!(args;
- [NaturalLit(n)] => BoolLit(n == 0),
- ),
- NaturalEven => improved_slice_patterns::match_vec!(args;
- [NaturalLit(n)] => BoolLit(n % 2 == 0),
- ),
- NaturalOdd => improved_slice_patterns::match_vec!(args;
- [NaturalLit(n)] => BoolLit(n % 2 != 0),
- ),
- NaturalToInteger => improved_slice_patterns::match_vec!(args;
- [NaturalLit(n)] => IntegerLit(n as isize),
- ),
- NaturalShow => improved_slice_patterns::match_vec!(args;
- [NaturalLit(n)] => {
- TextLit(vec![InterpolatedTextContents::Text(n.to_string())])
- }
- ),
- ListLength => improved_slice_patterns::match_vec!(args;
- [_, EmptyListLit(_)] => NaturalLit(0),
- [_, NEListLit(xs)] => NaturalLit(xs.len()),
- ),
- ListHead => improved_slice_patterns::match_vec!(args;
- [_, EmptyListLit(n)] => EmptyOptionalLit(n),
- [_, NEListLit(xs)] => {
- NEOptionalLit(xs.into_iter().next().unwrap())
+ // Return Ok((unconsumed args, returned value)), or Err(()) if value could not be produced.
+ let ret = match (b, args.as_slice()) {
+ (OptionalNone, [t, r..]) => {
+ Ok((r, EmptyOptionalLit(TypeThunk::from_thunk(t.clone()))))
+ }
+ (NaturalIsZero, [n, r..]) => match &*n.as_value() {
+ NaturalLit(n) => Ok((r, BoolLit(*n == 0))),
+ _ => Err(()),
+ },
+ (NaturalEven, [n, r..]) => match &*n.as_value() {
+ NaturalLit(n) => Ok((r, BoolLit(*n % 2 == 0))),
+ _ => Err(()),
+ },
+ (NaturalOdd, [n, r..]) => match &*n.as_value() {
+ NaturalLit(n) => Ok((r, BoolLit(*n % 2 != 0))),
+ _ => Err(()),
+ },
+ (NaturalToInteger, [n, r..]) => match &*n.as_value() {
+ NaturalLit(n) => Ok((r, IntegerLit(*n as isize))),
+ _ => Err(()),
+ },
+ (NaturalShow, [n, r..]) => match &*n.as_value() {
+ NaturalLit(n) => Ok((
+ r,
+ TextLit(vec![InterpolatedTextContents::Text(n.to_string())]),
+ )),
+ _ => Err(()),
+ },
+ (ListLength, [_, l, r..]) => match &*l.as_value() {
+ EmptyListLit(_) => Ok((r, NaturalLit(0))),
+ NEListLit(xs) => Ok((r, NaturalLit(xs.len()))),
+ _ => Err(()),
+ },
+ (ListHead, [_, l, r..]) => match &*l.as_value() {
+ EmptyListLit(n) => Ok((r, EmptyOptionalLit(n.clone()))),
+ NEListLit(xs) => {
+ Ok((r, NEOptionalLit(xs.iter().next().unwrap().clone())))
}
- ),
- ListLast => improved_slice_patterns::match_vec!(args;
- [_, EmptyListLit(n)] => EmptyOptionalLit(n),
- [_, NEListLit(xs)] => {
- NEOptionalLit(xs.into_iter().rev().next().unwrap())
+ _ => Err(()),
+ },
+ (ListLast, [_, l, r..]) => match &*l.as_value() {
+ EmptyListLit(n) => Ok((r, EmptyOptionalLit(n.clone()))),
+ NEListLit(xs) => {
+ Ok((r, NEOptionalLit(xs.iter().rev().next().unwrap().clone())))
}
- ),
- ListReverse => improved_slice_patterns::match_vec!(args;
- [_, EmptyListLit(n)] => EmptyListLit(n),
- [_, NEListLit(xs)] => {
- let mut xs = xs;
- xs.reverse();
- NEListLit(xs)
+ _ => Err(()),
+ },
+ (ListReverse, [_, l, r..]) => match &*l.as_value() {
+ EmptyListLit(n) => Ok((r, EmptyListLit(n.clone()))),
+ NEListLit(xs) => {
+ Ok((r, NEListLit(xs.iter().rev().cloned().collect())))
}
- ),
- ListIndexed => improved_slice_patterns::match_vec!(args;
- [_, EmptyListLit(t)] => {
+ _ => Err(()),
+ },
+ (ListIndexed, [_, l, r..]) => match &*l.as_value() {
+ EmptyListLit(t) => {
let mut kts = BTreeMap::new();
kts.insert(
"index".into(),
- TypeThunk::from_whnf(
- Value::from_builtin(Natural)
- ),
+ TypeThunk::from_whnf(Value::from_builtin(Natural)),
);
- kts.insert("value".into(), t);
- EmptyListLit(TypeThunk::from_whnf(RecordType(kts)))
- },
- [_, NEListLit(xs)] => {
+ kts.insert("value".into(), t.clone());
+ Ok((r, EmptyListLit(TypeThunk::from_whnf(RecordType(kts)))))
+ }
+ NEListLit(xs) => {
let xs = xs
- .into_iter()
+ .iter()
.enumerate()
.map(|(i, e)| {
let i = NaturalLit(i);
let mut kvs = BTreeMap::new();
kvs.insert("index".into(), Thunk::from_whnf(i));
- kvs.insert("value".into(), e);
+ kvs.insert("value".into(), e.clone());
Thunk::from_whnf(RecordLit(kvs))
})
.collect();
- NEListLit(xs)
+ Ok((r, NEListLit(xs)))
}
- ),
- ListBuild => improved_slice_patterns::match_vec!(args;
+ _ => Err(()),
+ },
+ (ListBuild, [t, f, r..]) => match &*f.as_value() {
// fold/build fusion
- [_, Value::AppliedBuiltin(ListFold, args)] => {
- let mut args = args;
+ Value::AppliedBuiltin(ListFold, args) => {
if args.len() >= 2 {
- args.remove(1)
+ Ok((r, args[1].to_value()))
} else {
// Do we really need to handle this case ?
unimplemented!()
}
- },
- [t, g] => g
- .app(Value::from_builtin(List).app(t.clone()))
- .app(ListConsClosure(TypeThunk::from_whnf(t.clone()), None))
- .app(EmptyListLit(TypeThunk::from_whnf(t))),
- ),
- ListFold => improved_slice_patterns::match_vec!(args;
- // fold/build fusion
- [_, Value::AppliedBuiltin(ListBuild, args)] => {
- let mut args = args;
- if args.len() >= 2 {
- args.remove(1)
- } else {
- unimplemented!()
- }
- },
- [_, EmptyListLit(_), _, _, nil] => nil,
- [_, NEListLit(xs), _, cons, nil] => {
- let mut v = nil;
- for x in xs.into_iter().rev() {
- v = cons.clone().app_thunk(x).app(v);
- }
- v
}
- ),
- OptionalBuild => improved_slice_patterns::match_vec!(args;
- // fold/build fusion
- [_, Value::AppliedBuiltin(OptionalFold, args)] => {
- let mut args = args;
- if args.len() >= 2 {
- args.remove(1)
- } else {
- unimplemented!()
+ _ => Ok((
+ r,
+ f.app_val(Value::from_builtin(List).app_thunk(t.clone()))
+ .app_val(ListConsClosure(
+ TypeThunk::from_thunk(t.clone()),
+ None,
+ ))
+ .app_val(EmptyListLit(TypeThunk::from_thunk(t.clone()))),
+ )),
+ },
+ (ListFold, [_, l, _, cons, nil, r..]) => match &*l.as_value() {
+ EmptyListLit(_) => Ok((r, nil.to_value())),
+ NEListLit(xs) => {
+ let mut v = nil.clone();
+ for x in xs.iter().rev() {
+ v = cons
+ .clone()
+ .app_thunk(x.clone())
+ .app_thunk(v)
+ .into_thunk();
}
- },
- [t, g] => g
- .app(Value::from_builtin(Optional).app(t.clone()))
- .app(OptionalSomeClosure(TypeThunk::from_whnf(t.clone())))
- .app(EmptyOptionalLit(TypeThunk::from_whnf(t))),
- ),
- OptionalFold => improved_slice_patterns::match_vec!(args;
+ Ok((r, v.to_value()))
+ }
+ _ => Err(()),
+ },
+ (OptionalBuild, [t, f, r..]) => match &*f.as_value() {
// fold/build fusion
- [_, Value::AppliedBuiltin(OptionalBuild, args)] => {
- let mut args = args;
+ Value::AppliedBuiltin(OptionalFold, args) => {
if args.len() >= 2 {
- args.remove(1)
+ Ok((r, args[1].to_value()))
} else {
+ // Do we really need to handle this case ?
unimplemented!()
}
- },
- [_, EmptyOptionalLit(_), _, _, nothing] => {
- nothing
- },
- [_, NEOptionalLit(x), _, just, _] => {
- just.app_thunk(x)
}
- ),
- NaturalBuild => improved_slice_patterns::match_vec!(args;
- // fold/build fusion
- [Value::AppliedBuiltin(NaturalFold, args)] => {
- let mut args = args;
- if args.len() >= 1 {
- args.remove(0)
- } else {
- unimplemented!()
- }
- },
- [g] => g
- .app(Value::from_builtin(Natural))
- .app(NaturalSuccClosure)
- .app(NaturalLit(0)),
- ),
- NaturalFold => improved_slice_patterns::match_vec!(args;
+ _ => Ok((
+ r,
+ f.app_val(Value::from_builtin(Optional).app_thunk(t.clone()))
+ .app_val(OptionalSomeClosure(TypeThunk::from_thunk(
+ t.clone(),
+ )))
+ .app_val(EmptyOptionalLit(TypeThunk::from_thunk(
+ t.clone(),
+ ))),
+ )),
+ },
+ (OptionalFold, [_, v, _, just, nothing, r..]) => match &*v.as_value() {
+ EmptyOptionalLit(_) => Ok((r, nothing.to_value())),
+ NEOptionalLit(x) => Ok((r, just.app_thunk(x.clone()))),
+ _ => Err(()),
+ },
+ (NaturalBuild, [f, r..]) => match &*f.as_value() {
// fold/build fusion
- [Value::AppliedBuiltin(NaturalBuild, args)] => {
- let mut args = args;
+ Value::AppliedBuiltin(NaturalFold, args) => {
if args.len() >= 1 {
- args.remove(0)
+ Ok((r, args[0].to_value()))
} else {
+ // Do we really need to handle this case ?
unimplemented!()
}
- },
- [NaturalLit(0), _, _, zero] => zero,
- [NaturalLit(n), t, succ, zero] => {
+ }
+ _ => Ok((
+ r,
+ f.app_val(Value::from_builtin(Natural))
+ .app_val(NaturalSuccClosure)
+ .app_val(NaturalLit(0)),
+ )),
+ },
+ (NaturalFold, [n, t, succ, zero, r..]) => match &*n.as_value() {
+ NaturalLit(0) => Ok((r, zero.to_value())),
+ NaturalLit(n) => {
let fold = Value::from_builtin(NaturalFold)
.app(NaturalLit(n - 1))
- .app(t)
- .app(succ.clone())
- .app(zero);
- succ.app(fold)
- },
- ),
- _ => Err(args),
+ .app_thunk(t.clone())
+ .app_thunk(succ.clone())
+ .app_thunk(zero.clone());
+ Ok((r, succ.app_val(fold)))
+ }
+ _ => Err(()),
+ },
+ _ => Err(()),
};
-
match ret {
- Ok(x) => x,
- Err(args) => AppliedBuiltin(b, args),
+ Ok((unconsumed_args, mut v)) => {
+ let n_consumed_args = args.len() - unconsumed_args.len();
+ for x in args.into_iter().skip(n_consumed_args) {
+ v = v.app_thunk(x);
+ }
+ v
+ }
+ Err(()) => AppliedBuiltin(b, args),
}
}
@@ -337,7 +338,7 @@ impl NormalizationContext {
pub(crate) enum Value {
/// Closures
Lam(Label, Thunk, Thunk),
- AppliedBuiltin(Builtin, Vec<Value>),
+ AppliedBuiltin(Builtin, Vec<Thunk>),
/// `λ(x: a) -> Some x`
OptionalSomeClosure(TypeThunk),
/// `λ(x : a) -> λ(xs : List a) -> [ x ] # xs`
@@ -671,6 +672,11 @@ impl Value {
/// Apply to a value
pub(crate) fn app(self, val: Value) -> Value {
+ self.app_val(val)
+ }
+
+ /// Apply to a value
+ pub(crate) fn app_val(self, val: Value) -> Value {
self.app_thunk(val.into_thunk())
}
@@ -692,7 +698,7 @@ impl Value {
e.subst_shift(&V(x, 0), &val).normalize_whnf().clone()
}
Value::AppliedBuiltin(b, mut args) => {
- args.push(th.normalize_whnf().clone());
+ args.push(th.clone());
apply_builtin(b, args)
}
Value::OptionalSomeClosure(_) => Value::NEOptionalLit(th),
@@ -1136,6 +1142,22 @@ mod thunk {
self.normalize_nf().normalize_to_expr()
}
+ pub(crate) fn as_value(&self) -> Ref<Value> {
+ self.normalize_whnf()
+ }
+
+ pub(crate) fn to_value(&self) -> Value {
+ self.normalize_whnf().clone()
+ }
+
+ pub(crate) fn app_val(&self, val: Value) -> Value {
+ self.to_value().app(val)
+ }
+
+ pub(crate) fn app_thunk(&self, th: Thunk) -> Value {
+ self.to_value().app_thunk(th)
+ }
+
pub(crate) fn shift(&self, delta: isize, var: &V<Label>) -> Self {
self.0.borrow().shift(delta, var).into_thunk()
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-23 05:27:30 +0000