diff options
Diffstat (limited to 'dhall/src')
| -rw-r--r-- | dhall/src/normalize.rs | 86 |
1 files changed, 64 insertions, 22 deletions
diff --git a/dhall/src/normalize.rs b/dhall/src/normalize.rs index f3b0979..7a92d35 100644 --- a/dhall/src/normalize.rs +++ b/dhall/src/normalize.rs @@ -78,7 +78,7 @@ fn apply_builtin(b: Builtin, args: Vec<WHNF>) -> WHNF { let ret = match b { OptionalNone => improved_slice_patterns::match_vec!(args; - [t] => EmptyOptionalLit(Thunk::from_whnf(t)), + [t] => EmptyOptionalLit(TypeThunk::from_whnf(t)), ), NaturalIsZero => improved_slice_patterns::match_vec!(args; [NaturalLit(n)] => BoolLit(n == 0), @@ -126,12 +126,12 @@ fn apply_builtin(b: Builtin, args: Vec<WHNF>) -> WHNF { let mut kts = BTreeMap::new(); kts.insert( "index".into(), - Thunk::from_whnf( + TypeThunk::from_whnf( WHNF::from_builtin(Natural) ), ); kts.insert("value".into(), t); - EmptyListLit(Thunk::from_whnf(RecordType(kts))) + EmptyListLit(TypeThunk::from_whnf(RecordType(kts))) }, [_, NEListLit(xs)] => { let xs = xs @@ -161,8 +161,8 @@ fn apply_builtin(b: Builtin, args: Vec<WHNF>) -> WHNF { }, [t, g] => g .app(WHNF::from_builtin(List).app(t.clone())) - .app(ListConsClosure(Thunk::from_whnf(t.clone()), None)) - .app(EmptyListLit(Thunk::from_whnf(t))), + .app(ListConsClosure(TypeThunk::from_whnf(t.clone()), None)) + .app(EmptyListLit(TypeThunk::from_whnf(t))), ), ListFold => improved_slice_patterns::match_vec!(args; // fold/build fusion @@ -195,8 +195,8 @@ fn apply_builtin(b: Builtin, args: Vec<WHNF>) -> WHNF { }, [t, g] => g .app(WHNF::from_builtin(Optional).app(t.clone())) - .app(OptionalSomeClosure(Thunk::from_whnf(t.clone()))) - .app(EmptyOptionalLit(Thunk::from_whnf(t))), + .app(OptionalSomeClosure(TypeThunk::from_whnf(t.clone()))) + .app(EmptyOptionalLit(TypeThunk::from_whnf(t))), ), OptionalFold => improved_slice_patterns::match_vec!(args; // fold/build fusion @@ -347,22 +347,22 @@ pub(crate) enum WHNF { Lam(Label, Thunk, (NormalizationContext, InputSubExpr)), AppliedBuiltin(Builtin, Vec<WHNF>), /// `λ(x: a) -> Some x` - OptionalSomeClosure(Thunk), + OptionalSomeClosure(TypeThunk), /// `λ(x : a) -> λ(xs : List a) -> [ x ] # xs` /// `λ(xs : List a) -> [ x ] # xs` - ListConsClosure(Thunk, Option<Thunk>), + ListConsClosure(TypeThunk, Option<Thunk>), /// `λ(x : Natural) -> x + 1` NaturalSuccClosure, BoolLit(bool), NaturalLit(Natural), IntegerLit(Integer), - EmptyOptionalLit(Thunk), + EmptyOptionalLit(TypeThunk), NEOptionalLit(Thunk), - EmptyListLit(Thunk), + EmptyListLit(TypeThunk), NEListLit(Vec<Thunk>), RecordLit(BTreeMap<Label, Thunk>), - RecordType(BTreeMap<Label, Thunk>), + RecordType(BTreeMap<Label, TypeThunk>), UnionType(NormalizationContext, BTreeMap<Label, Option<InputSubExpr>>), UnionConstructor( NormalizationContext, @@ -569,11 +569,13 @@ impl WHNF { | WHNF::BoolLit(_) | WHNF::NaturalLit(_) | WHNF::IntegerLit(_) => {} - WHNF::EmptyOptionalLit(n) - | WHNF::NEOptionalLit(n) - | WHNF::OptionalSomeClosure(n) - | WHNF::EmptyListLit(n) => { - n.shift(delta, var); + WHNF::EmptyOptionalLit(tth) + | WHNF::OptionalSomeClosure(tth) + | WHNF::EmptyListLit(tth) => { + tth.shift(delta, var); + } + WHNF::NEOptionalLit(th) => { + th.shift(delta, var); } WHNF::Lam(x, t, (_, e)) => { t.shift(delta, var); @@ -595,7 +597,12 @@ impl WHNF { x.shift(delta, var); } } - WHNF::RecordLit(kvs) | WHNF::RecordType(kvs) => { + WHNF::RecordLit(kvs) => { + for x in kvs.values_mut() { + x.shift(delta, var); + } + } + WHNF::RecordType(kvs) => { for x in kvs.values_mut() { x.shift(delta, var); } @@ -634,11 +641,11 @@ pub(crate) enum Thunk { } impl Thunk { - fn new(ctx: NormalizationContext, e: InputSubExpr) -> Thunk { + fn new(ctx: NormalizationContext, e: InputSubExpr) -> Self { Thunk::Unnormalized(ctx, e) } - fn from_whnf(v: WHNF) -> Thunk { + fn from_whnf(v: WHNF) -> Self { Thunk::Normalized(Box::new(v)) } @@ -657,6 +664,39 @@ impl Thunk { } } +/// A thunk in type position. +#[derive(Debug, Clone)] +pub(crate) enum TypeThunk { + Thunk(Thunk), + // Type(Type<'static>), +} + +impl TypeThunk { + fn new(ctx: NormalizationContext, e: InputSubExpr) -> Self { + TypeThunk::from_thunk(Thunk::new(ctx, e)) + } + + fn from_thunk(th: Thunk) -> Self { + TypeThunk::Thunk(th) + } + + fn from_whnf(v: WHNF) -> Self { + TypeThunk::from_thunk(Thunk::from_whnf(v)) + } + + fn normalize(self) -> WHNF { + match self { + TypeThunk::Thunk(th) => th.normalize(), + } + } + + fn shift(&mut self, delta: isize, var: &V<Label>) { + match self { + TypeThunk::Thunk(th) => th.shift(delta, var), + } + } +} + /// Reduces the imput expression to WHNF. See doc on `WHNF` for details. fn normalize_whnf(ctx: NormalizationContext, expr: InputSubExpr) -> WHNF { match expr.as_ref() { @@ -680,13 +720,15 @@ fn normalize_whnf(ctx: NormalizationContext, expr: InputSubExpr) -> WHNF { ExprF::BoolLit(b) => WHNF::BoolLit(*b), ExprF::NaturalLit(n) => WHNF::NaturalLit(*n), ExprF::OldOptionalLit(None, e) => { - WHNF::EmptyOptionalLit(Thunk::new(ctx, e.clone())) + WHNF::EmptyOptionalLit(TypeThunk::new(ctx, e.clone())) } ExprF::OldOptionalLit(Some(e), _) => { WHNF::NEOptionalLit(Thunk::new(ctx, e.clone())) } ExprF::SomeLit(e) => WHNF::NEOptionalLit(Thunk::new(ctx, e.clone())), - ExprF::EmptyListLit(e) => WHNF::EmptyListLit(Thunk::new(ctx, e.clone())), + ExprF::EmptyListLit(e) => { + WHNF::EmptyListLit(TypeThunk::new(ctx, e.clone())) + } ExprF::NEListLit(elts) => WHNF::NEListLit( elts.iter() .map(|e| Thunk::new(ctx.clone(), e.clone())) |