diff options
| -rw-r--r-- | dhall/src/typecheck.rs | 79 |
1 files changed, 38 insertions, 41 deletions
diff --git a/dhall/src/typecheck.rs b/dhall/src/typecheck.rs index a9b9d7d..22d3c42 100644 --- a/dhall/src/typecheck.rs +++ b/dhall/src/typecheck.rs @@ -6,7 +6,7 @@ use crate::normalize::normalize; use dhall_core; use dhall_core::context::Context; use dhall_core::*; -use dhall_generator::dhall_expr; +use dhall_generator as dhall; use self::TypeMessage::*; @@ -112,31 +112,31 @@ where go::<S, T>(&mut ctx, eL0, eR0) } -fn type_of_builtin<S>(b: Builtin) -> SubExpr<S, X> { +fn type_of_builtin<S>(b: Builtin) -> Expr<S, X> { use dhall_core::Builtin::*; match b { - Bool | Natural | Integer | Double | Text => dhall_expr!(Type), - List | Optional => dhall_expr!( + Bool | Natural | Integer | Double | Text => dhall::expr!(Type), + List | Optional => dhall::expr!( Type -> Type ), - NaturalFold => dhall_expr!( + NaturalFold => dhall::expr!( Natural -> forall (natural: Type) -> forall (succ: natural -> natural) -> forall (zero: natural) -> natural ), - NaturalBuild => dhall_expr!( + NaturalBuild => dhall::expr!( (forall (natural: Type) -> forall (succ: natural -> natural) -> forall (zero: natural) -> natural) -> Natural ), - NaturalIsZero | NaturalEven | NaturalOdd => dhall_expr!( + NaturalIsZero | NaturalEven | NaturalOdd => dhall::expr!( Natural -> Bool ), - ListBuild => dhall_expr!( + ListBuild => dhall::expr!( forall (a: Type) -> (forall (list: Type) -> forall (cons: a -> list -> list) -> @@ -144,7 +144,7 @@ fn type_of_builtin<S>(b: Builtin) -> SubExpr<S, X> { list) -> List a ), - ListFold => dhall_expr!( + ListFold => dhall::expr!( forall (a: Type) -> List a -> forall (list: Type) -> @@ -152,19 +152,19 @@ fn type_of_builtin<S>(b: Builtin) -> SubExpr<S, X> { forall (nil: list) -> list ), - ListLength => dhall_expr!(forall (a: Type) -> List a -> Natural), + ListLength => dhall::expr!(forall (a: Type) -> List a -> Natural), ListHead | ListLast => { - dhall_expr!(forall (a: Type) -> List a -> Optional a) + dhall::expr!(forall (a: Type) -> List a -> Optional a) } - ListIndexed => dhall_expr!( + ListIndexed => dhall::expr!( forall (a: Type) -> List a -> List { index: Natural, value: a } ), - ListReverse => dhall_expr!( + ListReverse => dhall::expr!( forall (a: Type) -> List a -> List a ), - OptionalFold => dhall_expr!( + OptionalFold => dhall::expr!( forall (a: Type) -> Optional a -> forall (optional: Type) -> @@ -205,22 +205,20 @@ where _ => Err(mkerr(msg)), }; - match e.as_ref() { + let ret = match e.as_ref() { Const(c) => axiom(*c).map(Const), - Var(V(x, n)) => { - return ctx - .lookup(x, *n) - .cloned() - .ok_or_else(|| mkerr(UnboundVariable)) - } + Var(V(x, n)) => match ctx.lookup(x, *n) { + Some(e) => Ok(e.unroll()), + None => Err(mkerr(UnboundVariable)), + }, Lam(x, tA, b) => { let ctx2 = ctx .insert(x.clone(), tA.clone()) .map(|e| shift(1, &V(x.clone(), 0), e)); let tB = normalized_type_with(&ctx2, b.clone())?; - let p = rc(Pi(x.clone(), tA.clone(), tB)); - let _ = type_with(ctx, p.clone())?; - return Ok(p); + let p = Pi(x.clone(), tA.clone(), tB); + let _ = normalized_type_with(ctx, rc(p.clone()))?; + Ok(p) } Pi(x, tA, tB) => { let tA2 = normalized_type_with(ctx, tA.clone())?; @@ -267,7 +265,7 @@ where let tA2 = normalized_type_with(ctx, a.clone())?; if prop_equal(tA.as_ref(), tA2.as_ref()) { let vx0 = &V(x.clone(), 0); - return Ok(subst_shift(vx0, &a, &tB)); + Ok(subst_shift(vx0, &a, &tB).unroll()) } else { Err(mkerr(TypeMismatch(f.clone(), tA.clone(), a.clone(), tA2))) } @@ -296,16 +294,16 @@ where return Err(mkerr(NoDependentLet(tR, tB))); } - return Ok(tB); + Ok(tB.unroll()) } Annot(x, t) => { // This is mainly just to check that `t` is not `Kind` - let _ = type_with(ctx, t.clone())?; + let _ = normalized_type_with(ctx, t.clone())?; let t2 = normalized_type_with(ctx, x.clone())?; let t = normalize(t.clone()); if prop_equal(t.as_ref(), t2.as_ref()) { - return Ok(t.clone()); + Ok(t.unroll()) } else { Err(mkerr(AnnotMismatch(x.clone(), t, t2))) } @@ -340,13 +338,13 @@ where tz, ))); } - return Ok(ty); + Ok(ty.unroll()) } EmptyListLit(t) => { let s = normalized_type_with(ctx, t.clone())?; ensure_is_type(s, InvalidListType(t.clone()))?; let t = normalize(SubExpr::clone(t)); - return Ok(dhall_expr!(List t)); + Ok(dhall::expr!(List t)) } NEListLit(xs) => { let mut iter = xs.iter().enumerate(); @@ -360,19 +358,19 @@ where return Err(mkerr(InvalidListElement(i, t, x.clone(), t2))); } } - return Ok(dhall_expr!(List t)); + Ok(dhall::expr!(List t)) } EmptyOptionalLit(t) => { let s = normalized_type_with(ctx, t.clone())?; ensure_is_type(s, InvalidOptionalType(t.clone()))?; let t = normalize(t.clone()); - return Ok(dhall_expr!(Optional t)); + Ok(dhall::expr!(Optional t)) } NEOptionalLit(x) => { let t = normalized_type_with(ctx, x.clone())?; let s = normalized_type_with(ctx, t.clone())?; ensure_is_type(s, InvalidOptionalType(t.clone()))?; - return Ok(dhall_expr!(Optional t)); + Ok(dhall::expr!(Optional t)) } RecordType(kts) => { for (k, t) in kts { @@ -396,15 +394,14 @@ where Field(r, x) => { let t = normalized_type_with(ctx, r.clone())?; match t.as_ref() { - RecordType(kts) => { - return kts.get(x).cloned().ok_or_else(|| { - mkerr(MissingField(x.clone(), t.clone())) - }) - } + RecordType(kts) => match kts.get(x) { + Some(e) => Ok(e.unroll()), + None => Err(mkerr(MissingField(x.clone(), t.clone()))), + }, _ => Err(mkerr(NotARecord(x.clone(), r.clone(), t.clone()))), } } - Builtin(b) => return Ok(type_of_builtin(*b)), + Builtin(b) => Ok(type_of_builtin(*b)), BoolLit(_) => Ok(Builtin(Bool)), NaturalLit(_) => Ok(Builtin(Natural)), IntegerLit(_) => Ok(Builtin(Integer)), @@ -437,8 +434,8 @@ where } Embed(p) => match *p {}, _ => panic!("Unimplemented typecheck case: {:?}", e), - } - .map(rc) + }?; + Ok(rc(ret)) } pub fn normalized_type_with<S>( |