1 files changed, 48 insertions, 40 deletions

diff --git a/crates/hir_ty/src/lower.rs b/crates/hir_ty/src/lower.rs
index 99b0ecf3b..1b5843d48 100644
--- a/crates/hir_ty/src/lower.rs
+++ b/crates/hir_ty/src/lower.rs
@@ -8,6 +8,7 @@
 use std::{iter, sync::Arc};
 
 use base_db::CrateId;
+use chalk_ir::Mutability;
 use hir_def::{
     adt::StructKind,
     builtin_type::BuiltinType,
@@ -31,9 +32,9 @@ use crate::{
         all_super_trait_refs, associated_type_by_name_including_super_traits, generics,
         make_mut_slice, variant_data,
     },
-    Binders, BoundVar, DebruijnIndex, FnSig, GenericPredicate, OpaqueTy, OpaqueTyId, PolyFnSig,
-    ProjectionPredicate, ProjectionTy, ReturnTypeImplTrait, ReturnTypeImplTraits, Substs,
-    TraitEnvironment, TraitRef, Ty, TypeCtor, TypeWalk,
+    AliasTy, Binders, BoundVar, CallableSig, DebruijnIndex, FnPointer, FnSig, GenericPredicate,
+    OpaqueTy, OpaqueTyId, PolyFnSig, ProjectionPredicate, ProjectionTy, ReturnTypeImplTrait,
+    ReturnTypeImplTraits, Substs, TraitEnvironment, TraitRef, Ty, TypeWalk,
 };
 
 #[derive(Debug)]
@@ -145,13 +146,10 @@ impl Ty {
     pub fn from_hir_ext(ctx: &TyLoweringContext<'_>, type_ref: &TypeRef) -> (Self, Option<TypeNs>) {
         let mut res = None;
         let ty = match type_ref {
-            TypeRef::Never => Ty::simple(TypeCtor::Never),
+            TypeRef::Never => Ty::Never,
             TypeRef::Tuple(inner) => {
                 let inner_tys: Arc<[Ty]> = inner.iter().map(|tr| Ty::from_hir(ctx, tr)).collect();
-                Ty::apply(
-                    TypeCtor::Tuple { cardinality: inner_tys.len() as u16 },
-                    Substs(inner_tys),
-                )
+                Ty::Tuple(inner_tys.len(), Substs(inner_tys))
             }
             TypeRef::Path(path) => {
                 let (ty, res_) = Ty::from_hir_path(ctx, path);
@@ -160,30 +158,31 @@ impl Ty {
             }
             TypeRef::RawPtr(inner, mutability) => {
                 let inner_ty = Ty::from_hir(ctx, inner);
-                Ty::apply_one(TypeCtor::RawPtr(*mutability), inner_ty)
+                Ty::Raw(lower_to_chalk_mutability(*mutability), Substs::single(inner_ty))
             }
             TypeRef::Array(inner) => {
                 let inner_ty = Ty::from_hir(ctx, inner);
-                Ty::apply_one(TypeCtor::Array, inner_ty)
+                Ty::Array(Substs::single(inner_ty))
             }
             TypeRef::Slice(inner) => {
                 let inner_ty = Ty::from_hir(ctx, inner);
-                Ty::apply_one(TypeCtor::Slice, inner_ty)
+                Ty::Slice(Substs::single(inner_ty))
             }
             TypeRef::Reference(inner, _, mutability) => {
                 let inner_ty = Ty::from_hir(ctx, inner);
-                Ty::apply_one(TypeCtor::Ref(*mutability), inner_ty)
+                Ty::Ref(lower_to_chalk_mutability(*mutability), Substs::single(inner_ty))
             }
             TypeRef::Placeholder => Ty::Unknown,
             TypeRef::Fn(params, is_varargs) => {
-                let sig = Substs(params.iter().map(|tr| Ty::from_hir(ctx, tr)).collect());
-                Ty::apply(
-                    TypeCtor::FnPtr { num_args: sig.len() as u16 - 1, is_varargs: *is_varargs },
-                    sig,
-                )
+                let substs = Substs(params.iter().map(|tr| Ty::from_hir(ctx, tr)).collect());
+                Ty::Function(FnPointer {
+                    num_args: substs.len() - 1,
+                    sig: FnSig { variadic: *is_varargs },
+                    substs,
+                })
             }
             TypeRef::DynTrait(bounds) => {
-                let self_ty = Ty::Bound(BoundVar::new(DebruijnIndex::INNERMOST, 0));
+                let self_ty = Ty::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, 0));
                 let predicates = ctx.with_shifted_in(DebruijnIndex::ONE, |ctx| {
                     bounds
                         .iter()
@@ -227,7 +226,10 @@ impl Ty {
                         let impl_trait_id = OpaqueTyId::ReturnTypeImplTrait(func, idx);
                         let generics = generics(ctx.db.upcast(), func.into());
                         let parameters = Substs::bound_vars(&generics, ctx.in_binders);
-                        Ty::Opaque(OpaqueTy { opaque_ty_id: impl_trait_id, parameters })
+                        Ty::Alias(AliasTy::Opaque(OpaqueTy {
+                            opaque_ty_id: impl_trait_id,
+                            parameters,
+                        }))
                     }
                     ImplTraitLoweringMode::Param => {
                         let idx = ctx.impl_trait_counter.get();
@@ -258,7 +260,7 @@ impl Ty {
                             } else {
                                 (0, 0, 0, 0)
                             };
-                        Ty::Bound(BoundVar::new(
+                        Ty::BoundVar(BoundVar::new(
                             ctx.in_binders,
                             idx as usize + parent_params + self_params + list_params,
                         ))
@@ -330,7 +332,7 @@ impl Ty {
             TypeNs::TraitId(trait_) => {
                 // if this is a bare dyn Trait, we'll directly put the required ^0 for the self type in there
                 let self_ty = if remaining_segments.len() == 0 {
-                    Some(Ty::Bound(BoundVar::new(DebruijnIndex::INNERMOST, 0)))
+                    Some(Ty::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, 0)))
                 } else {
                     None
                 };
@@ -346,10 +348,10 @@ impl Ty {
                     match found {
                         Some((super_trait_ref, associated_ty)) => {
                             // FIXME handle type parameters on the segment
-                            Ty::Projection(ProjectionTy {
+                            Ty::Alias(AliasTy::Projection(ProjectionTy {
                                 associated_ty,
                                 parameters: super_trait_ref.substs,
-                            })
+                            }))
                         }
                         None => {
                             // FIXME: report error (associated type not found)
@@ -373,7 +375,7 @@ impl Ty {
                     TypeParamLoweringMode::Placeholder => Ty::Placeholder(param_id),
                     TypeParamLoweringMode::Variable => {
                         let idx = generics.param_idx(param_id).expect("matching generics");
-                        Ty::Bound(BoundVar::new(ctx.in_binders, idx))
+                        Ty::BoundVar(BoundVar::new(ctx.in_binders, idx))
                     }
                 }
             }
@@ -414,7 +416,6 @@ impl Ty {
             // FIXME: report error
             TypeNs::EnumVariantId(_) => return (Ty::Unknown, None),
         };
-
         Ty::from_type_relative_path(ctx, ty, Some(resolution), remaining_segments)
     }
 
@@ -472,10 +473,10 @@ impl Ty {
                         // associated_type_shorthand_candidates does not do that
                         let substs = substs.shift_bound_vars(ctx.in_binders);
                         // FIXME handle type parameters on the segment
-                        return Some(Ty::Projection(ProjectionTy {
+                        return Some(Ty::Alias(AliasTy::Projection(ProjectionTy {
                             associated_ty,
                             parameters: substs,
-                        }));
+                        })));
                     }
 
                     None
@@ -676,7 +677,7 @@ impl GenericPredicate {
                             TypeParamLoweringMode::Placeholder => Ty::Placeholder(param_id),
                             TypeParamLoweringMode::Variable => {
                                 let idx = generics.param_idx(param_id).expect("matching generics");
-                                Ty::Bound(BoundVar::new(DebruijnIndex::INNERMOST, idx))
+                                Ty::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, idx))
                             }
                         }
                     }
@@ -750,7 +751,7 @@ fn assoc_type_bindings_from_type_bound<'a>(
                 preds.extend(GenericPredicate::from_type_bound(
                     ctx,
                     bound,
-                    Ty::Projection(projection_ty.clone()),
+                    Ty::Alias(AliasTy::Projection(projection_ty.clone())),
                 ));
             }
             preds
@@ -760,7 +761,7 @@ fn assoc_type_bindings_from_type_bound<'a>(
 impl ReturnTypeImplTrait {
     fn from_hir(ctx: &TyLoweringContext, bounds: &[TypeBound]) -> Self {
         mark::hit!(lower_rpit);
-        let self_ty = Ty::Bound(BoundVar::new(DebruijnIndex::INNERMOST, 0));
+        let self_ty = Ty::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, 0));
         let predicates = ctx.with_shifted_in(DebruijnIndex::ONE, |ctx| {
             bounds
                 .iter()
@@ -984,7 +985,7 @@ pub(crate) fn generic_defaults_query(
             // Each default can only refer to previous parameters.
             ty.walk_mut_binders(
                 &mut |ty, binders| match ty {
-                    Ty::Bound(BoundVar { debruijn, index }) if *debruijn == binders => {
+                    Ty::BoundVar(BoundVar { debruijn, index }) if *debruijn == binders => {
                         if *index >= idx {
                             // type variable default referring to parameter coming
                             // after it. This is forbidden (FIXME: report
@@ -1017,7 +1018,7 @@ fn fn_sig_for_fn(db: &dyn HirDatabase, def: FunctionId) -> PolyFnSig {
     let ret = Ty::from_hir(&ctx_ret, &data.ret_type);
     let generics = generics(db.upcast(), def.into());
     let num_binders = generics.len();
-    Binders::new(num_binders, FnSig::from_params_and_return(params, ret, data.is_varargs))
+    Binders::new(num_binders, CallableSig::from_params_and_return(params, ret, data.is_varargs))
 }
 
 /// Build the declared type of a function. This should not need to look at the
@@ -1025,7 +1026,7 @@ fn fn_sig_for_fn(db: &dyn HirDatabase, def: FunctionId) -> PolyFnSig {
 fn type_for_fn(db: &dyn HirDatabase, def: FunctionId) -> Binders<Ty> {
     let generics = generics(db.upcast(), def.into());
     let substs = Substs::bound_vars(&generics, DebruijnIndex::INNERMOST);
-    Binders::new(substs.len(), Ty::apply(TypeCtor::FnDef(def.into()), substs))
+    Binders::new(substs.len(), Ty::FnDef(def.into(), substs))
 }
 
 /// Build the declared type of a const.
@@ -1057,7 +1058,7 @@ fn fn_sig_for_struct_constructor(db: &dyn HirDatabase, def: StructId) -> PolyFnS
     let params =
         fields.iter().map(|(_, field)| Ty::from_hir(&ctx, &field.type_ref)).collect::<Vec<_>>();
     let ret = type_for_adt(db, def.into());
-    Binders::new(ret.num_binders, FnSig::from_params_and_return(params, ret.value, false))
+    Binders::new(ret.num_binders, CallableSig::from_params_and_return(params, ret.value, false))
 }
 
 /// Build the type of a tuple struct constructor.
@@ -1068,7 +1069,7 @@ fn type_for_struct_constructor(db: &dyn HirDatabase, def: StructId) -> Binders<T
     }
     let generics = generics(db.upcast(), def.into());
     let substs = Substs::bound_vars(&generics, DebruijnIndex::INNERMOST);
-    Binders::new(substs.len(), Ty::apply(TypeCtor::FnDef(def.into()), substs))
+    Binders::new(substs.len(), Ty::FnDef(def.into(), substs))
 }
 
 fn fn_sig_for_enum_variant_constructor(db: &dyn HirDatabase, def: EnumVariantId) -> PolyFnSig {
@@ -1081,7 +1082,7 @@ fn fn_sig_for_enum_variant_constructor(db: &dyn HirDatabase, def: EnumVariantId)
     let params =
         fields.iter().map(|(_, field)| Ty::from_hir(&ctx, &field.type_ref)).collect::<Vec<_>>();
     let ret = type_for_adt(db, def.parent.into());
-    Binders::new(ret.num_binders, FnSig::from_params_and_return(params, ret.value, false))
+    Binders::new(ret.num_binders, CallableSig::from_params_and_return(params, ret.value, false))
 }
 
 /// Build the type of a tuple enum variant constructor.
@@ -1093,13 +1094,13 @@ fn type_for_enum_variant_constructor(db: &dyn HirDatabase, def: EnumVariantId) -
     }
     let generics = generics(db.upcast(), def.parent.into());
     let substs = Substs::bound_vars(&generics, DebruijnIndex::INNERMOST);
-    Binders::new(substs.len(), Ty::apply(TypeCtor::FnDef(def.into()), substs))
+    Binders::new(substs.len(), Ty::FnDef(def.into(), substs))
 }
 
 fn type_for_adt(db: &dyn HirDatabase, adt: AdtId) -> Binders<Ty> {
     let generics = generics(db.upcast(), adt.into());
     let substs = Substs::bound_vars(&generics, DebruijnIndex::INNERMOST);
-    Binders::new(substs.len(), Ty::apply(TypeCtor::Adt(adt), substs))
+    Binders::new(substs.len(), Ty::Adt(adt, substs))
 }
 
 fn type_for_type_alias(db: &dyn HirDatabase, t: TypeAliasId) -> Binders<Ty> {
@@ -1107,10 +1108,10 @@ fn type_for_type_alias(db: &dyn HirDatabase, t: TypeAliasId) -> Binders<Ty> {
     let resolver = t.resolver(db.upcast());
     let ctx =
         TyLoweringContext::new(db, &resolver).with_type_param_mode(TypeParamLoweringMode::Variable);
-    let substs = Substs::bound_vars(&generics, DebruijnIndex::INNERMOST);
     if db.type_alias_data(t).is_extern {
-        Binders::new(substs.len(), Ty::apply(TypeCtor::ForeignType(t), substs))
+        Binders::new(0, Ty::ForeignType(t))
     } else {
+        let substs = Substs::bound_vars(&generics, DebruijnIndex::INNERMOST);
         let type_ref = &db.type_alias_data(t).type_ref;
         let inner = Ty::from_hir(&ctx, type_ref.as_ref().unwrap_or(&TypeRef::Error));
         Binders::new(substs.len(), inner)
@@ -1259,3 +1260,10 @@ pub(crate) fn return_type_impl_traits(
         Some(Arc::new(Binders::new(num_binders, return_type_impl_traits)))
     }
 }
+
+pub(crate) fn lower_to_chalk_mutability(m: hir_def::type_ref::Mutability) -> Mutability {
+    match m {
+        hir_def::type_ref::Mutability::Shared => Mutability::Not,
+        hir_def::type_ref::Mutability::Mut => Mutability::Mut,
+    }
+}