diff options
Diffstat (limited to 'dhall/src')
| -rw-r--r-- | dhall/src/normalize.rs | 120 |
1 files changed, 96 insertions, 24 deletions
diff --git a/dhall/src/normalize.rs b/dhall/src/normalize.rs index 5766766..d02dd80 100644 --- a/dhall/src/normalize.rs +++ b/dhall/src/normalize.rs @@ -244,15 +244,26 @@ where /// little as possible, but just enough to know the first constructor of the normal form. This is /// identical to full normalization for simple types like integers, but for e.g. a record literal /// this means knowing just the field names. +/// +/// Each variant captures the relevant contexts when it is constructed. Conceptually each +/// subexpression has its own context, but in practise contexts can be shared when sensible, to +/// avoid unnecessary allocations. #[derive(Debug, Clone)] enum WHNF { Closure(Closure), BoolLit(bool), NaturalLit(Natural), + EmptyOptionalLit(NormalizationContext, InputSubExpr), + NEOptionalLit(NormalizationContext, InputSubExpr), EmptyListLit(NormalizationContext, InputSubExpr), NEListLit(Vec<(NormalizationContext, Vec<InputSubExpr>)>), RecordLit(NormalizationContext, BTreeMap<Label, InputSubExpr>), UnionType(NormalizationContext, BTreeMap<Label, Option<InputSubExpr>>), + UnionLit( + Label, + Box<WHNF>, + (NormalizationContext, BTreeMap<Label, Option<InputSubExpr>>), + ), Expr(OutputSubExpr), } @@ -263,6 +274,12 @@ impl WHNF { WHNF::Closure(c) => c.normalize_to_expr(), WHNF::BoolLit(b) => rc(ExprF::BoolLit(b)), WHNF::NaturalLit(n) => rc(ExprF::NaturalLit(n)), + WHNF::EmptyOptionalLit(ctx, e) => rc(ExprF::EmptyOptionalLit( + normalize_whnf(&ctx, e).normalize_to_expr(), + )), + WHNF::NEOptionalLit(ctx, e) => rc(ExprF::NEOptionalLit( + normalize_whnf(&ctx, e).normalize_to_expr(), + )), WHNF::EmptyListLit(ctx, e) => rc(ExprF::EmptyListLit( normalize_whnf(&ctx, e).normalize_to_expr(), )), @@ -282,8 +299,8 @@ impl WHNF { }) .collect(), )), - WHNF::UnionType(ctx, kvs) => rc(ExprF::UnionType( - kvs.into_iter() + WHNF::UnionType(ctx, kts) => rc(ExprF::UnionType( + kts.into_iter() .map(|(k, v)| { ( k, @@ -294,6 +311,20 @@ impl WHNF { }) .collect(), )), + WHNF::UnionLit(l, v, (kts_ctx, kts)) => rc(ExprF::UnionLit( + l, + v.normalize_to_expr(), + kts.into_iter() + .map(|(k, v)| { + ( + k, + v.map(|v| { + normalize_whnf(&kts_ctx, v).normalize_to_expr() + }), + ) + }) + .collect(), + )), WHNF::Expr(e) => e, } } @@ -304,6 +335,12 @@ impl WHNF { WHNF::Expr(e) => WHNF::Expr(shift0(delta, label, &e)), WHNF::BoolLit(b) => WHNF::BoolLit(b), WHNF::NaturalLit(n) => WHNF::NaturalLit(n), + WHNF::EmptyOptionalLit(ctx, e) => { + WHNF::EmptyOptionalLit(ctx, shift0(delta, label, &e)) + } + WHNF::NEOptionalLit(ctx, e) => { + WHNF::NEOptionalLit(ctx, shift0(delta, label, &e)) + } WHNF::EmptyListLit(ctx, e) => { WHNF::EmptyListLit(ctx, shift0(delta, label, &e)) } @@ -325,12 +362,22 @@ impl WHNF { .map(|(k, v)| (k, shift0(delta, label, &v))) .collect(), ), - WHNF::UnionType(ctx, kvs) => WHNF::UnionType( + WHNF::UnionType(ctx, kts) => WHNF::UnionType( ctx, - kvs.into_iter() + kts.into_iter() .map(|(k, v)| (k, v.map(|v| shift0(delta, label, &v)))) .collect(), ), + WHNF::UnionLit(l, v, (kts_ctx, kts)) => WHNF::UnionLit( + l, + Box::new(v.shift0(delta, label)), + ( + kts_ctx, + kts.into_iter() + .map(|(k, v)| (k, v.map(|v| shift0(delta, label, &v)))) + .collect(), + ), + ), } } } @@ -368,18 +415,7 @@ impl Closure { } } Closure::UnionConstructor(ctx, l, kts) => { - let kts = kts - .into_iter() - .map(|(k, v)| { - ( - k, - v.map(|v| { - normalize_whnf(&ctx, v).normalize_to_expr() - }), - ) - }) - .collect(); - WHNF::Expr(rc(ExprF::UnionLit(l, val.normalize_to_expr(), kts))) + WHNF::UnionLit(l, Box::new(val), (ctx, kts)) } } } @@ -522,10 +558,17 @@ fn reval(ctx: &NormalizationContext, expr: OutputSubExpr) -> WHNF { } ExprF::BoolLit(b) => WHNF::BoolLit(b), ExprF::NaturalLit(n) => WHNF::NaturalLit(n), + ExprF::EmptyOptionalLit(e) => WHNF::EmptyOptionalLit(ctx.clone(), e), + ExprF::NEOptionalLit(e) => WHNF::NEOptionalLit(ctx.clone(), e), ExprF::EmptyListLit(e) => WHNF::EmptyListLit(ctx.clone(), e), ExprF::NEListLit(elts) => WHNF::NEListLit(vec![(ctx.clone(), elts)]), ExprF::RecordLit(kvs) => WHNF::RecordLit(ctx.clone(), kvs), ExprF::UnionType(kvs) => WHNF::UnionType(ctx.clone(), kvs), + ExprF::UnionLit(l, x, kts) => WHNF::UnionLit( + l, + Box::new(normalize_whnf(ctx, x)), + (ctx.clone(), kts), + ), _ => WHNF::Expr(expr), } } @@ -554,6 +597,18 @@ fn normalize_whnf(ctx: &NormalizationContext, expr: InputSubExpr) -> WHNF { } ExprF::BoolLit(b) => return WHNF::BoolLit(*b), ExprF::NaturalLit(n) => return WHNF::NaturalLit(*n), + ExprF::OldOptionalLit(None, t) => { + return WHNF::EmptyOptionalLit(ctx.clone(), t.clone()) + } + ExprF::OldOptionalLit(Some(x), _) => { + return WHNF::NEOptionalLit(ctx.clone(), x.clone()) + } + ExprF::EmptyOptionalLit(e) => { + return WHNF::EmptyOptionalLit(ctx.clone(), e.clone()) + } + ExprF::NEOptionalLit(e) => { + return WHNF::NEOptionalLit(ctx.clone(), e.clone()) + } ExprF::EmptyListLit(e) => { return WHNF::EmptyListLit(ctx.clone(), e.clone()) } @@ -566,6 +621,13 @@ fn normalize_whnf(ctx: &NormalizationContext, expr: InputSubExpr) -> WHNF { ExprF::UnionType(kvs) => { return WHNF::UnionType(ctx.clone(), kvs.clone()) } + ExprF::UnionLit(l, x, kts) => { + return WHNF::UnionLit( + l.clone(), + Box::new(normalize_whnf(ctx, x.clone())), + (ctx.clone(), kts.clone()), + ) + } ExprF::BoolIf(b, e1, e2) => { let b = normalize_whnf(ctx, b.clone()); match b { @@ -687,6 +749,22 @@ fn normalize_last_layer( t, ), }, + Merge( + WHNF::RecordLit(record_ctx, mut handlers), + WHNF::UnionLit(l, v, (kts_ctx, kts)), + t, + ) => match handlers.remove(&l) { + Some(h) => { + let h = normalize_whnf(&kts_ctx, h); + return normalize_last_layer(ctx, App(h, *v)); + } + // Return ownership + None => Merge( + WHNF::RecordLit(record_ctx, handlers), + WHNF::UnionLit(l, v, (kts_ctx, kts)), + t, + ), + }, expr => expr, }; @@ -705,8 +783,7 @@ fn normalize_last_layer( BoolIf(BoolLit(_), _, _) => unreachable!(), // TODO: interpolation // TextLit(t) => - OldOptionalLit(None, t) => Done(EmptyOptionalLit(t.roll())), - OldOptionalLit(Some(x), _) => Done(NEOptionalLit(x.roll())), + OldOptionalLit(_, _) => unreachable!(), BinOp(BoolAnd, BoolLit(_), BoolLit(_)) => unreachable!(), BinOp(BoolOr, BoolLit(_), BoolLit(_)) => unreachable!(), BinOp(BoolEQ, BoolLit(_), BoolLit(_)) => unreachable!(), @@ -717,12 +794,7 @@ fn normalize_last_layer( BinOp(ListAppend, EmptyListLit(_), _) => unreachable!(), BinOp(ListAppend, _, EmptyListLit(_)) => unreachable!(), BinOp(ListAppend, NEListLit(_), NEListLit(_)) => unreachable!(), - Merge(RecordLit(handlers), UnionLit(l, v, _), _) => { - match handlers.get(&l) { - Some(h) => Continue(App(h.clone(), v.clone())), - None => DoneAsIs, - } - } + Merge(RecordLit(_), UnionLit(_, _, _), _) => unreachable!(), Field(RecordLit(_), _) => unreachable!(), Field(UnionType(_), _) => unreachable!(), Projection(_, ls) if ls.is_empty() => unreachable!(), |