3 files changed, 92 insertions, 206 deletions

diff --git a/crates/hir_ty/src/traits/chalk/interner.rs b/crates/hir_ty/src/traits/chalk/interner.rs
index 54bd1c724..1dc3f497d 100644
--- a/crates/hir_ty/src/traits/chalk/interner.rs
+++ b/crates/hir_ty/src/traits/chalk/interner.rs
@@ -12,7 +12,6 @@ pub struct Interner;
 
 pub(crate) type AssocTypeId = chalk_ir::AssocTypeId<Interner>;
 pub(crate) type AssociatedTyDatum = chalk_solve::rust_ir::AssociatedTyDatum<Interner>;
-pub(crate) type ForeignDefId = chalk_ir::ForeignDefId<Interner>;
 pub(crate) type TraitId = chalk_ir::TraitId<Interner>;
 pub(crate) type TraitDatum = chalk_solve::rust_ir::TraitDatum<Interner>;
 pub(crate) type AdtId = chalk_ir::AdtId<Interner>;
@@ -21,7 +20,6 @@ pub(crate) type ImplId = chalk_ir::ImplId<Interner>;
 pub(crate) type ImplDatum = chalk_solve::rust_ir::ImplDatum<Interner>;
 pub(crate) type AssociatedTyValueId = chalk_solve::rust_ir::AssociatedTyValueId<Interner>;
 pub(crate) type AssociatedTyValue = chalk_solve::rust_ir::AssociatedTyValue<Interner>;
-pub(crate) type FnDefId = chalk_ir::FnDefId<Interner>;
 pub(crate) type FnDefDatum = chalk_solve::rust_ir::FnDefDatum<Interner>;
 pub(crate) type OpaqueTyId = chalk_ir::OpaqueTyId<Interner>;
 pub(crate) type OpaqueTyDatum = chalk_solve::rust_ir::OpaqueTyDatum<Interner>;
diff --git a/crates/hir_ty/src/traits/chalk/mapping.rs b/crates/hir_ty/src/traits/chalk/mapping.rs
index 3a08b67e9..6a8b6752e 100644
--- a/crates/hir_ty/src/traits/chalk/mapping.rs
+++ b/crates/hir_ty/src/traits/chalk/mapping.rs
@@ -3,10 +3,7 @@
 //! Chalk (in both directions); plus some helper functions for more specialized
 //! conversions.
 
-use chalk_ir::{
-    cast::Cast, fold::shift::Shift, interner::HasInterner, LifetimeData, PlaceholderIndex,
-    UniverseIndex,
-};
+use chalk_ir::{cast::Cast, fold::shift::Shift, interner::HasInterner, LifetimeData};
 use chalk_solve::rust_ir;
 
 use base_db::salsa::InternKey;
@@ -14,10 +11,11 @@ use hir_def::{AssocContainerId, GenericDefId, Lookup, TypeAliasId};
 
 use crate::{
     db::HirDatabase,
+    from_assoc_type_id,
     primitive::UintTy,
     traits::{Canonical, Obligation},
-    AliasTy, CallableDefId, FnPointer, FnSig, GenericPredicate, InEnvironment, OpaqueTy,
-    OpaqueTyId, ProjectionPredicate, ProjectionTy, Scalar, Substs, TraitEnvironment, TraitRef, Ty,
+    AliasTy, CallableDefId, FnPointer, GenericPredicate, InEnvironment, OpaqueTy,
+    ProjectionPredicate, ProjectionTy, Scalar, Substs, TraitRef, Ty,
 };
 
 use super::interner::*;
@@ -26,71 +24,60 @@ use super::*;
 impl ToChalk for Ty {
     type Chalk = chalk_ir::Ty<Interner>;
     fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::Ty<Interner> {
-        match self {
-            Ty::Ref(m, parameters) => ref_to_chalk(db, m, parameters),
-            Ty::Array(parameters) => array_to_chalk(db, parameters),
-            Ty::Function(FnPointer { sig: FnSig { variadic }, substs, .. }) => {
+        match self.into_inner() {
+            TyKind::Ref(m, ty) => ref_to_chalk(db, m, ty),
+            TyKind::Array(ty) => array_to_chalk(db, ty),
+            TyKind::Function(FnPointer { sig, substs, .. }) => {
                 let substitution = chalk_ir::FnSubst(substs.to_chalk(db).shifted_in(&Interner));
                 chalk_ir::TyKind::Function(chalk_ir::FnPointer {
                     num_binders: 0,
-                    sig: chalk_ir::FnSig { abi: (), safety: chalk_ir::Safety::Safe, variadic },
+                    sig,
                     substitution,
                 })
                 .intern(&Interner)
             }
-            Ty::AssociatedType(type_alias, substs) => {
-                let assoc_type = TypeAliasAsAssocType(type_alias);
-                let assoc_type_id = assoc_type.to_chalk(db);
+            TyKind::AssociatedType(assoc_type_id, substs) => {
                 let substitution = substs.to_chalk(db);
                 chalk_ir::TyKind::AssociatedType(assoc_type_id, substitution).intern(&Interner)
             }
 
-            Ty::OpaqueType(impl_trait_id, substs) => {
-                let id = impl_trait_id.to_chalk(db);
+            TyKind::OpaqueType(id, substs) => {
                 let substitution = substs.to_chalk(db);
                 chalk_ir::TyKind::OpaqueType(id, substitution).intern(&Interner)
             }
 
-            Ty::ForeignType(type_alias) => {
-                let foreign_type = TypeAliasAsForeignType(type_alias);
-                let foreign_type_id = foreign_type.to_chalk(db);
-                chalk_ir::TyKind::Foreign(foreign_type_id).intern(&Interner)
-            }
+            TyKind::ForeignType(id) => chalk_ir::TyKind::Foreign(id).intern(&Interner),
 
-            Ty::Scalar(scalar) => chalk_ir::TyKind::Scalar(scalar).intern(&Interner),
+            TyKind::Scalar(scalar) => chalk_ir::TyKind::Scalar(scalar).intern(&Interner),
 
-            Ty::Tuple(cardinality, substs) => {
+            TyKind::Tuple(cardinality, substs) => {
                 let substitution = substs.to_chalk(db);
                 chalk_ir::TyKind::Tuple(cardinality.into(), substitution).intern(&Interner)
             }
-            Ty::Raw(mutability, substs) => {
-                let ty = substs[0].clone().to_chalk(db);
+            TyKind::Raw(mutability, ty) => {
+                let ty = ty.to_chalk(db);
                 chalk_ir::TyKind::Raw(mutability, ty).intern(&Interner)
             }
-            Ty::Slice(substs) => {
-                chalk_ir::TyKind::Slice(substs[0].clone().to_chalk(db)).intern(&Interner)
-            }
-            Ty::Str => chalk_ir::TyKind::Str.intern(&Interner),
-            Ty::FnDef(callable_def, substs) => {
-                let id = callable_def.to_chalk(db);
+            TyKind::Slice(ty) => chalk_ir::TyKind::Slice(ty.to_chalk(db)).intern(&Interner),
+            TyKind::Str => chalk_ir::TyKind::Str.intern(&Interner),
+            TyKind::FnDef(id, substs) => {
                 let substitution = substs.to_chalk(db);
                 chalk_ir::TyKind::FnDef(id, substitution).intern(&Interner)
             }
-            Ty::Never => chalk_ir::TyKind::Never.intern(&Interner),
+            TyKind::Never => chalk_ir::TyKind::Never.intern(&Interner),
 
-            Ty::Closure(def, expr, substs) => {
-                let closure_id = db.intern_closure((def, expr));
+            TyKind::Closure(closure_id, substs) => {
                 let substitution = substs.to_chalk(db);
-                chalk_ir::TyKind::Closure(closure_id.into(), substitution).intern(&Interner)
+                chalk_ir::TyKind::Closure(closure_id, substitution).intern(&Interner)
             }
 
-            Ty::Adt(adt_id, substs) => {
+            TyKind::Adt(adt_id, substs) => {
                 let substitution = substs.to_chalk(db);
                 chalk_ir::TyKind::Adt(adt_id, substitution).intern(&Interner)
             }
-            Ty::Alias(AliasTy::Projection(proj_ty)) => {
-                let associated_ty_id = TypeAliasAsAssocType(proj_ty.associated_ty).to_chalk(db);
-                let substitution = proj_ty.parameters.to_chalk(db);
+            TyKind::Alias(AliasTy::Projection(proj_ty)) => {
+                let associated_ty_id = proj_ty.associated_ty_id;
+                let substitution = proj_ty.substitution.to_chalk(db);
                 chalk_ir::AliasTy::Projection(chalk_ir::ProjectionTy {
                     associated_ty_id,
                     substitution,
@@ -98,17 +85,17 @@ impl ToChalk for Ty {
                 .cast(&Interner)
                 .intern(&Interner)
             }
-            Ty::Placeholder(id) => {
-                let interned_id = db.intern_type_param_id(id);
-                PlaceholderIndex {
-                    ui: UniverseIndex::ROOT,
-                    idx: interned_id.as_intern_id().as_usize(),
-                }
-                .to_ty::<Interner>(&Interner)
-            }
-            Ty::BoundVar(idx) => chalk_ir::TyKind::BoundVar(idx).intern(&Interner),
-            Ty::InferenceVar(..) => panic!("uncanonicalized infer ty"),
-            Ty::Dyn(predicates) => {
+            TyKind::Alias(AliasTy::Opaque(opaque_ty)) => {
+                let opaque_ty_id = opaque_ty.opaque_ty_id;
+                let substitution = opaque_ty.substitution.to_chalk(db);
+                chalk_ir::AliasTy::Opaque(chalk_ir::OpaqueTy { opaque_ty_id, substitution })
+                    .cast(&Interner)
+                    .intern(&Interner)
+            }
+            TyKind::Placeholder(idx) => idx.to_ty::<Interner>(&Interner),
+            TyKind::BoundVar(idx) => chalk_ir::TyKind::BoundVar(idx).intern(&Interner),
+            TyKind::InferenceVar(..) => panic!("uncanonicalized infer ty"),
+            TyKind::Dyn(predicates) => {
                 let where_clauses = chalk_ir::QuantifiedWhereClauses::from_iter(
                     &Interner,
                     predicates.iter().filter(|p| !p.is_error()).cloned().map(|p| p.to_chalk(db)),
@@ -119,43 +106,30 @@ impl ToChalk for Ty {
                 };
                 chalk_ir::TyKind::Dyn(bounded_ty).intern(&Interner)
             }
-            Ty::Alias(AliasTy::Opaque(opaque_ty)) => {
-                let opaque_ty_id = opaque_ty.opaque_ty_id.to_chalk(db);
-                let substitution = opaque_ty.parameters.to_chalk(db);
-                chalk_ir::TyKind::Alias(chalk_ir::AliasTy::Opaque(chalk_ir::OpaqueTy {
-                    opaque_ty_id,
-                    substitution,
-                }))
-                .intern(&Interner)
-            }
-            Ty::Unknown => chalk_ir::TyKind::Error.intern(&Interner),
+            TyKind::Unknown => chalk_ir::TyKind::Error.intern(&Interner),
         }
     }
     fn from_chalk(db: &dyn HirDatabase, chalk: chalk_ir::Ty<Interner>) -> Self {
         match chalk.data(&Interner).kind.clone() {
-            chalk_ir::TyKind::Error => Ty::Unknown,
-            chalk_ir::TyKind::Array(ty, _size) => Ty::Array(Substs::single(from_chalk(db, ty))),
-            chalk_ir::TyKind::Placeholder(idx) => {
-                assert_eq!(idx.ui, UniverseIndex::ROOT);
-                let interned_id = crate::db::GlobalTypeParamId::from_intern_id(
-                    crate::salsa::InternId::from(idx.idx),
-                );
-                Ty::Placeholder(db.lookup_intern_type_param_id(interned_id))
-            }
+            chalk_ir::TyKind::Error => TyKind::Unknown,
+            chalk_ir::TyKind::Array(ty, _size) => TyKind::Array(from_chalk(db, ty)),
+            chalk_ir::TyKind::Placeholder(idx) => TyKind::Placeholder(idx),
             chalk_ir::TyKind::Alias(chalk_ir::AliasTy::Projection(proj)) => {
-                let associated_ty =
-                    from_chalk::<TypeAliasAsAssocType, _>(db, proj.associated_ty_id).0;
+                let associated_ty = proj.associated_ty_id;
                 let parameters = from_chalk(db, proj.substitution);
-                Ty::Alias(AliasTy::Projection(ProjectionTy { associated_ty, parameters }))
+                TyKind::Alias(AliasTy::Projection(ProjectionTy {
+                    associated_ty_id: associated_ty,
+                    substitution: parameters,
+                }))
             }
             chalk_ir::TyKind::Alias(chalk_ir::AliasTy::Opaque(opaque_ty)) => {
-                let impl_trait_id = from_chalk(db, opaque_ty.opaque_ty_id);
+                let opaque_ty_id = opaque_ty.opaque_ty_id;
                 let parameters = from_chalk(db, opaque_ty.substitution);
-                Ty::Alias(AliasTy::Opaque(OpaqueTy { opaque_ty_id: impl_trait_id, parameters }))
+                TyKind::Alias(AliasTy::Opaque(OpaqueTy { opaque_ty_id, substitution: parameters }))
             }
             chalk_ir::TyKind::Function(chalk_ir::FnPointer {
                 num_binders,
-                sig: chalk_ir::FnSig { variadic, .. },
+                sig,
                 substitution,
                 ..
             }) => {
@@ -164,14 +138,10 @@ impl ToChalk for Ty {
                     db,
                     substitution.0.shifted_out(&Interner).expect("fn ptr should have no binders"),
                 );
-                Ty::Function(FnPointer {
-                    num_args: (substs.len() - 1),
-                    sig: FnSig { variadic },
-                    substs,
-                })
+                TyKind::Function(FnPointer { num_args: (substs.len() - 1), sig, substs })
             }
-            chalk_ir::TyKind::BoundVar(idx) => Ty::BoundVar(idx),
-            chalk_ir::TyKind::InferenceVar(_iv, _kind) => Ty::Unknown,
+            chalk_ir::TyKind::BoundVar(idx) => TyKind::BoundVar(idx),
+            chalk_ir::TyKind::InferenceVar(_iv, _kind) => TyKind::Unknown,
             chalk_ir::TyKind::Dyn(where_clauses) => {
                 assert_eq!(where_clauses.bounds.binders.len(&Interner), 1);
                 let predicates = where_clauses
@@ -180,49 +150,41 @@ impl ToChalk for Ty {
                     .iter(&Interner)
                     .map(|c| from_chalk(db, c.clone()))
                     .collect();
-                Ty::Dyn(predicates)
+                TyKind::Dyn(predicates)
             }
 
-            chalk_ir::TyKind::Adt(adt_id, subst) => Ty::Adt(adt_id, from_chalk(db, subst)),
-            chalk_ir::TyKind::AssociatedType(type_id, subst) => Ty::AssociatedType(
-                from_chalk::<TypeAliasAsAssocType, _>(db, type_id).0,
-                from_chalk(db, subst),
-            ),
+            chalk_ir::TyKind::Adt(adt_id, subst) => TyKind::Adt(adt_id, from_chalk(db, subst)),
+            chalk_ir::TyKind::AssociatedType(type_id, subst) => {
+                TyKind::AssociatedType(type_id, from_chalk(db, subst))
+            }
 
             chalk_ir::TyKind::OpaqueType(opaque_type_id, subst) => {
-                Ty::OpaqueType(from_chalk(db, opaque_type_id), from_chalk(db, subst))
+                TyKind::OpaqueType(opaque_type_id, from_chalk(db, subst))
             }
 
-            chalk_ir::TyKind::Scalar(scalar) => Ty::Scalar(scalar),
+            chalk_ir::TyKind::Scalar(scalar) => TyKind::Scalar(scalar),
             chalk_ir::TyKind::Tuple(cardinality, subst) => {
-                Ty::Tuple(cardinality, from_chalk(db, subst))
+                TyKind::Tuple(cardinality, from_chalk(db, subst))
             }
-            chalk_ir::TyKind::Raw(mutability, ty) => {
-                Ty::Raw(mutability, Substs::single(from_chalk(db, ty)))
-            }
-            chalk_ir::TyKind::Slice(ty) => Ty::Slice(Substs::single(from_chalk(db, ty))),
+            chalk_ir::TyKind::Raw(mutability, ty) => TyKind::Raw(mutability, from_chalk(db, ty)),
+            chalk_ir::TyKind::Slice(ty) => TyKind::Slice(from_chalk(db, ty)),
             chalk_ir::TyKind::Ref(mutability, _lifetime, ty) => {
-                Ty::Ref(mutability, Substs::single(from_chalk(db, ty)))
+                TyKind::Ref(mutability, from_chalk(db, ty))
             }
-            chalk_ir::TyKind::Str => Ty::Str,
-            chalk_ir::TyKind::Never => Ty::Never,
+            chalk_ir::TyKind::Str => TyKind::Str,
+            chalk_ir::TyKind::Never => TyKind::Never,
 
             chalk_ir::TyKind::FnDef(fn_def_id, subst) => {
-                Ty::FnDef(from_chalk(db, fn_def_id), from_chalk(db, subst))
+                TyKind::FnDef(fn_def_id, from_chalk(db, subst))
             }
 
-            chalk_ir::TyKind::Closure(id, subst) => {
-                let id: crate::db::ClosureId = id.into();
-                let (def, expr) = db.lookup_intern_closure(id);
-                Ty::Closure(def, expr, from_chalk(db, subst))
-            }
+            chalk_ir::TyKind::Closure(id, subst) => TyKind::Closure(id, from_chalk(db, subst)),
 
-            chalk_ir::TyKind::Foreign(foreign_def_id) => {
-                Ty::ForeignType(from_chalk::<TypeAliasAsForeignType, _>(db, foreign_def_id).0)
-            }
+            chalk_ir::TyKind::Foreign(foreign_def_id) => TyKind::ForeignType(foreign_def_id),
             chalk_ir::TyKind::Generator(_, _) => unimplemented!(), // FIXME
             chalk_ir::TyKind::GeneratorWitness(_, _) => unimplemented!(), // FIXME
         }
+        .intern(&Interner)
     }
 }
 
@@ -231,17 +193,17 @@ impl ToChalk for Ty {
 fn ref_to_chalk(
     db: &dyn HirDatabase,
     mutability: chalk_ir::Mutability,
-    subst: Substs,
+    ty: Ty,
 ) -> chalk_ir::Ty<Interner> {
-    let arg = subst[0].clone().to_chalk(db);
+    let arg = ty.to_chalk(db);
     let lifetime = LifetimeData::Static.intern(&Interner);
     chalk_ir::TyKind::Ref(mutability, lifetime, arg).intern(&Interner)
 }
 
 /// We currently don't model constants, but Chalk does. So, we have to insert a
 /// fake constant here, because Chalks built-in logic may expect it to be there.
-fn array_to_chalk(db: &dyn HirDatabase, subst: Substs) -> chalk_ir::Ty<Interner> {
-    let arg = subst[0].clone().to_chalk(db);
+fn array_to_chalk(db: &dyn HirDatabase, ty: Ty) -> chalk_ir::Ty<Interner> {
+    let arg = ty.to_chalk(db);
     let usize_ty = chalk_ir::TyKind::Scalar(Scalar::Uint(UintTy::Usize)).intern(&Interner);
     let const_ = chalk_ir::ConstData {
         ty: usize_ty,
@@ -298,21 +260,6 @@ impl ToChalk for hir_def::TraitId {
     }
 }
 
-impl ToChalk for OpaqueTyId {
-    type Chalk = chalk_ir::OpaqueTyId<Interner>;
-
-    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::OpaqueTyId<Interner> {
-        db.intern_impl_trait_id(self).into()
-    }
-
-    fn from_chalk(
-        db: &dyn HirDatabase,
-        opaque_ty_id: chalk_ir::OpaqueTyId<Interner>,
-    ) -> OpaqueTyId {
-        db.lookup_intern_impl_trait_id(opaque_ty_id.into())
-    }
-}
-
 impl ToChalk for hir_def::ImplId {
     type Chalk = ImplId;
 
@@ -337,34 +284,6 @@ impl ToChalk for CallableDefId {
     }
 }
 
-pub(crate) struct TypeAliasAsAssocType(pub(crate) TypeAliasId);
-
-impl ToChalk for TypeAliasAsAssocType {
-    type Chalk = AssocTypeId;
-
-    fn to_chalk(self, _db: &dyn HirDatabase) -> AssocTypeId {
-        chalk_ir::AssocTypeId(self.0.as_intern_id())
-    }
-
-    fn from_chalk(_db: &dyn HirDatabase, assoc_type_id: AssocTypeId) -> TypeAliasAsAssocType {
-        TypeAliasAsAssocType(InternKey::from_intern_id(assoc_type_id.0))
-    }
-}
-
-pub(crate) struct TypeAliasAsForeignType(pub(crate) TypeAliasId);
-
-impl ToChalk for TypeAliasAsForeignType {
-    type Chalk = ForeignDefId;
-
-    fn to_chalk(self, _db: &dyn HirDatabase) -> ForeignDefId {
-        chalk_ir::ForeignDefId(self.0.as_intern_id())
-    }
-
-    fn from_chalk(_db: &dyn HirDatabase, foreign_def_id: ForeignDefId) -> TypeAliasAsForeignType {
-        TypeAliasAsForeignType(InternKey::from_intern_id(foreign_def_id.0))
-    }
-}
-
 pub(crate) struct TypeAliasAsValue(pub(crate) TypeAliasId);
 
 impl ToChalk for TypeAliasAsValue {
@@ -446,8 +365,8 @@ impl ToChalk for ProjectionTy {
 
     fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::ProjectionTy<Interner> {
         chalk_ir::ProjectionTy {
-            associated_ty_id: TypeAliasAsAssocType(self.associated_ty).to_chalk(db),
-            substitution: self.parameters.to_chalk(db),
+            associated_ty_id: self.associated_ty_id,
+            substitution: self.substitution.to_chalk(db),
         }
     }
 
@@ -456,12 +375,8 @@ impl ToChalk for ProjectionTy {
         projection_ty: chalk_ir::ProjectionTy<Interner>,
     ) -> ProjectionTy {
         ProjectionTy {
-            associated_ty: from_chalk::<TypeAliasAsAssocType, _>(
-                db,
-                projection_ty.associated_ty_id,
-            )
-            .0,
-            parameters: from_chalk(db, projection_ty.substitution),
+            associated_ty_id: projection_ty.associated_ty_id,
+            substitution: from_chalk(db, projection_ty.substitution),
         }
     }
 }
@@ -536,31 +451,6 @@ where
     }
 }
 
-impl ToChalk for Arc<TraitEnvironment> {
-    type Chalk = chalk_ir::Environment<Interner>;
-
-    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::Environment<Interner> {
-        let mut clauses = Vec::new();
-        for pred in &self.predicates {
-            if pred.is_error() {
-                // for env, we just ignore errors
-                continue;
-            }
-            let program_clause: chalk_ir::ProgramClause<Interner> =
-                pred.clone().to_chalk(db).cast(&Interner);
-            clauses.push(program_clause.into_from_env_clause(&Interner));
-        }
-        chalk_ir::Environment::new(&Interner).add_clauses(&Interner, clauses)
-    }
-
-    fn from_chalk(
-        _db: &dyn HirDatabase,
-        _env: chalk_ir::Environment<Interner>,
-    ) -> Arc<TraitEnvironment> {
-        unimplemented!()
-    }
-}
-
 impl<T: ToChalk> ToChalk for InEnvironment<T>
 where
     T::Chalk: chalk_ir::interner::HasInterner<Interner = Interner>,
@@ -569,19 +459,16 @@ where
 
     fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::InEnvironment<T::Chalk> {
         chalk_ir::InEnvironment {
-            environment: self.environment.to_chalk(db),
+            environment: self.environment.env.clone(),
             goal: self.value.to_chalk(db),
         }
     }
 
     fn from_chalk(
-        db: &dyn HirDatabase,
-        in_env: chalk_ir::InEnvironment<T::Chalk>,
+        _db: &dyn HirDatabase,
+        _in_env: chalk_ir::InEnvironment<T::Chalk>,
     ) -> InEnvironment<T> {
-        InEnvironment {
-            environment: from_chalk(db, in_env.environment),
-            value: from_chalk(db, in_env.goal),
-        }
+        unimplemented!()
     }
 }
 
@@ -639,22 +526,24 @@ pub(super) fn generic_predicate_to_inline_bound(
             Some(rust_ir::InlineBound::TraitBound(trait_bound))
         }
         GenericPredicate::Projection(proj) => {
-            if &proj.projection_ty.parameters[0] != self_ty {
+            if &proj.projection_ty.substitution[0] != self_ty {
                 return None;
             }
-            let trait_ = match proj.projection_ty.associated_ty.lookup(db.upcast()).container {
+            let trait_ = match from_assoc_type_id(proj.projection_ty.associated_ty_id)
+                .lookup(db.upcast())
+                .container
+            {
                 AssocContainerId::TraitId(t) => t,
                 _ => panic!("associated type not in trait"),
             };
-            let args_no_self = proj.projection_ty.parameters[1..]
+            let args_no_self = proj.projection_ty.substitution[1..]
                 .iter()
                 .map(|ty| ty.clone().to_chalk(db).cast(&Interner))
                 .collect();
             let alias_eq_bound = rust_ir::AliasEqBound {
                 value: proj.ty.clone().to_chalk(db),
                 trait_bound: rust_ir::TraitBound { trait_id: trait_.to_chalk(db), args_no_self },
-                associated_ty_id: TypeAliasAsAssocType(proj.projection_ty.associated_ty)
-                    .to_chalk(db),
+                associated_ty_id: proj.projection_ty.associated_ty_id,
                 parameters: Vec::new(), // FIXME we don't support generic associated types yet
             };
             Some(rust_ir::InlineBound::AliasEqBound(alias_eq_bound))
diff --git a/crates/hir_ty/src/traits/chalk/tls.rs b/crates/hir_ty/src/traits/chalk/tls.rs
index 75b16172e..8892a63a9 100644
--- a/crates/hir_ty/src/traits/chalk/tls.rs
+++ b/crates/hir_ty/src/traits/chalk/tls.rs
@@ -4,8 +4,8 @@ use std::fmt;
 use chalk_ir::{AliasTy, GenericArg, Goal, Goals, Lifetime, ProgramClauseImplication};
 use itertools::Itertools;
 
-use super::{from_chalk, Interner, TypeAliasAsAssocType};
-use crate::{db::HirDatabase, CallableDefId};
+use super::{from_chalk, Interner};
+use crate::{db::HirDatabase, from_assoc_type_id, CallableDefId};
 use hir_def::{AdtId, AssocContainerId, Lookup, TypeAliasId};
 
 pub(crate) use unsafe_tls::{set_current_program, with_current_program};
@@ -41,7 +41,7 @@ impl DebugContext<'_> {
         id: super::AssocTypeId,
         fmt: &mut fmt::Formatter<'_>,
     ) -> Result<(), fmt::Error> {
-        let type_alias: TypeAliasId = from_chalk::<TypeAliasAsAssocType, _>(self.0, id).0;
+        let type_alias: TypeAliasId = from_assoc_type_id(id);
         let type_alias_data = self.0.type_alias_data(type_alias);
         let trait_ = match type_alias.lookup(self.0.upcast()).container {
             AssocContainerId::TraitId(t) => t,
@@ -75,8 +75,7 @@ impl DebugContext<'_> {
         projection_ty: &chalk_ir::ProjectionTy<Interner>,
         fmt: &mut fmt::Formatter<'_>,
     ) -> Result<(), fmt::Error> {
-        let type_alias: TypeAliasId =
-            from_chalk::<TypeAliasAsAssocType, _>(self.0, projection_ty.associated_ty_id).0;
+        let type_alias = from_assoc_type_id(projection_ty.associated_ty_id);
         let type_alias_data = self.0.type_alias_data(type_alias);
         let trait_ = match type_alias.lookup(self.0.upcast()).container {
             AssocContainerId::TraitId(t) => t,