7 files changed, 70 insertions, 62 deletions

diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index ae730beb5..f7fc80d4e 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -538,14 +538,6 @@ pub enum DefWithBody {
 impl_froms!(DefWithBody: Function, Const, Static);
 
 impl DefWithBody {
-    pub(crate) fn krate(self, db: &impl HirDatabase) -> Option<Crate> {
-        match self {
-            DefWithBody::Const(c) => c.krate(db),
-            DefWithBody::Function(f) => f.krate(db),
-            DefWithBody::Static(s) => s.krate(db),
-        }
-    }
-
     pub fn module(self, db: &impl HirDatabase) -> Module {
         match self {
             DefWithBody::Const(c) => c.module(db),
diff --git a/crates/ra_hir/src/ty.rs b/crates/ra_hir/src/ty.rs
index 3cbcbd1d0..388530f31 100644
--- a/crates/ra_hir/src/ty.rs
+++ b/crates/ra_hir/src/ty.rs
@@ -17,12 +17,15 @@ use std::ops::Deref;
 use std::sync::Arc;
 use std::{fmt, iter, mem};
 
-use hir_def::{generics::GenericParams, AdtId, GenericDefId};
+use hir_def::{
+    generics::GenericParams, AdtId, ContainerId, DefWithBodyId, GenericDefId, HasModule, Lookup,
+    TraitId, TypeAliasId,
+};
 use ra_db::{impl_intern_key, salsa};
 
 use crate::{
-    db::HirDatabase, expr::ExprId, util::make_mut_slice, Adt, Crate, DefWithBody, FloatTy, IntTy,
-    Mutability, Name, Trait, TypeAlias, Uncertain,
+    db::HirDatabase, expr::ExprId, util::make_mut_slice, Adt, Crate, FloatTy, IntTy, Mutability,
+    Name, Trait, Uncertain,
 };
 use display::{HirDisplay, HirFormatter};
 
@@ -107,13 +110,13 @@ pub enum TypeCtor {
     /// when we have tried to normalize a projection like `T::Item` but
     /// couldn't find a better representation.  In that case, we generate
     /// an **application type** like `(Iterator::Item)<T>`.
-    AssociatedType(TypeAlias),
+    AssociatedType(TypeAliasId),
 
     /// The type of a specific closure.
     ///
     /// The closure signature is stored in a `FnPtr` type in the first type
     /// parameter.
-    Closure { def: DefWithBody, expr: ExprId },
+    Closure { def: DefWithBodyId, expr: ExprId },
 }
 
 /// This exists just for Chalk, because Chalk just has a single `StructId` where
@@ -147,7 +150,7 @@ impl TypeCtor {
                 generic_params.count_params_including_parent()
             }
             TypeCtor::AssociatedType(type_alias) => {
-                let generic_params = db.generic_params(type_alias.id.into());
+                let generic_params = db.generic_params(type_alias.into());
                 generic_params.count_params_including_parent()
             }
             TypeCtor::FnPtr { num_args } => num_args as usize + 1,
@@ -169,10 +172,13 @@ impl TypeCtor {
             | TypeCtor::Ref(_)
             | TypeCtor::FnPtr { .. }
             | TypeCtor::Tuple { .. } => None,
-            TypeCtor::Closure { def, .. } => def.krate(db),
+            // Closure's krate is irrelevant for coherence I would think?
+            TypeCtor::Closure { .. } => None,
             TypeCtor::Adt(adt) => adt.krate(db),
             TypeCtor::FnDef(callable) => Some(callable.krate(db).into()),
-            TypeCtor::AssociatedType(type_alias) => type_alias.krate(db),
+            TypeCtor::AssociatedType(type_alias) => {
+                Some(type_alias.lookup(db).module(db).krate.into())
+            }
         }
     }
 
@@ -193,7 +199,7 @@ impl TypeCtor {
             | TypeCtor::Closure { .. } => None,
             TypeCtor::Adt(adt) => Some(adt.into()),
             TypeCtor::FnDef(callable) => Some(callable.into()),
-            TypeCtor::AssociatedType(type_alias) => Some(type_alias.id.into()),
+            TypeCtor::AssociatedType(type_alias) => Some(type_alias.into()),
         }
     }
 }
@@ -212,18 +218,19 @@ pub struct ApplicationTy {
 /// trait and all its parameters are fully known.
 #[derive(Clone, PartialEq, Eq, Debug, Hash)]
 pub struct ProjectionTy {
-    pub associated_ty: TypeAlias,
+    pub associated_ty: TypeAliasId,
     pub parameters: Substs,
 }
 
 impl ProjectionTy {
     pub fn trait_ref(&self, db: &impl HirDatabase) -> TraitRef {
-        TraitRef {
-            trait_: self
-                .associated_ty
-                .parent_trait(db)
-                .expect("projection ty without parent trait"),
-            substs: self.parameters.clone(),
+        TraitRef { trait_: self.trait_(db).into(), substs: self.parameters.clone() }
+    }
+
+    fn trait_(&self, db: &impl HirDatabase) -> TraitId {
+        match self.associated_ty.lookup(db).container {
+            ContainerId::TraitId(it) => it,
+            _ => panic!("projection ty without parent trait"),
         }
     }
 }
@@ -895,11 +902,12 @@ impl HirDisplay for ApplicationTy {
                 }
             }
             TypeCtor::AssociatedType(type_alias) => {
-                let trait_name = type_alias
-                    .parent_trait(f.db)
-                    .and_then(|t| t.name(f.db))
-                    .unwrap_or_else(Name::missing);
-                let name = type_alias.name(f.db);
+                let trait_ = match type_alias.lookup(f.db).container {
+                    ContainerId::TraitId(it) => it,
+                    _ => panic!("not an associated type"),
+                };
+                let trait_name = f.db.trait_data(trait_).name.clone().unwrap_or_else(Name::missing);
+                let name = f.db.type_alias_data(type_alias).name.clone();
                 write!(f, "{}::{}", trait_name, name)?;
                 if self.parameters.len() > 0 {
                     write!(f, "<")?;
@@ -926,18 +934,15 @@ impl HirDisplay for ProjectionTy {
             return write!(f, "…");
         }
 
-        let trait_name = self
-            .associated_ty
-            .parent_trait(f.db)
-            .and_then(|t| t.name(f.db))
-            .unwrap_or_else(Name::missing);
+        let trait_name =
+            f.db.trait_data(self.trait_(f.db)).name.clone().unwrap_or_else(Name::missing);
         write!(f, "<{} as {}", self.parameters[0].display(f.db), trait_name,)?;
         if self.parameters.len() > 1 {
             write!(f, "<")?;
             f.write_joined(&self.parameters[1..], ", ")?;
             write!(f, ">")?;
         }
-        write!(f, ">::{}", self.associated_ty.name(f.db))?;
+        write!(f, ">::{}", f.db.type_alias_data(self.associated_ty).name)?;
         Ok(())
     }
 }
@@ -1000,7 +1005,10 @@ impl HirDisplay for Ty {
                                 write!(f, "<")?;
                                 angle_open = true;
                             }
-                            let name = projection_pred.projection_ty.associated_ty.name(f.db);
+                            let name =
+                                f.db.type_alias_data(projection_pred.projection_ty.associated_ty)
+                                    .name
+                                    .clone();
                             write!(f, "{} = ", name)?;
                             projection_pred.ty.hir_fmt(f)?;
                         }
@@ -1076,7 +1084,7 @@ impl HirDisplay for GenericPredicate {
                 write!(
                     f,
                     ">::{} = {}",
-                    projection_pred.projection_ty.associated_ty.name(f.db),
+                    f.db.type_alias_data(projection_pred.projection_ty.associated_ty).name,
                     projection_pred.ty.display(f.db)
                 )?;
             }
diff --git a/crates/ra_hir/src/ty/autoderef.rs b/crates/ra_hir/src/ty/autoderef.rs
index 44547197c..9e7593b8b 100644
--- a/crates/ra_hir/src/ty/autoderef.rs
+++ b/crates/ra_hir/src/ty/autoderef.rs
@@ -69,7 +69,7 @@ fn deref_by_trait(
 
     let projection = super::traits::ProjectionPredicate {
         ty: Ty::Bound(0),
-        projection_ty: super::ProjectionTy { associated_ty: target, parameters },
+        projection_ty: super::ProjectionTy { associated_ty: target.id, parameters },
     };
 
     let obligation = super::Obligation::Projection(projection);
diff --git a/crates/ra_hir/src/ty/infer/expr.rs b/crates/ra_hir/src/ty/infer/expr.rs
index 994a6d7e9..316cdc880 100644
--- a/crates/ra_hir/src/ty/infer/expr.rs
+++ b/crates/ra_hir/src/ty/infer/expr.rs
@@ -101,7 +101,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                         let projection = ProjectionPredicate {
                             ty: pat_ty.clone(),
                             projection_ty: ProjectionTy {
-                                associated_ty: into_iter_item_alias,
+                                associated_ty: into_iter_item_alias.id,
                                 parameters: Substs::single(iterable_ty),
                             },
                         };
@@ -137,8 +137,10 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                     TypeCtor::FnPtr { num_args: sig_tys.len() as u16 - 1 },
                     Substs(sig_tys.into()),
                 );
-                let closure_ty =
-                    Ty::apply_one(TypeCtor::Closure { def: self.owner, expr: tgt_expr }, sig_ty);
+                let closure_ty = Ty::apply_one(
+                    TypeCtor::Closure { def: self.owner.into(), expr: tgt_expr },
+                    sig_ty,
+                );
 
                 // Eagerly try to relate the closure type with the expected
                 // type, otherwise we often won't have enough information to
@@ -281,7 +283,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                         let projection = ProjectionPredicate {
                             ty: ty.clone(),
                             projection_ty: ProjectionTy {
-                                associated_ty: future_future_output_alias,
+                                associated_ty: future_future_output_alias.id,
                                 parameters: Substs::single(inner_ty),
                             },
                         };
@@ -300,7 +302,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                         let projection = ProjectionPredicate {
                             ty: ty.clone(),
                             projection_ty: ProjectionTy {
-                                associated_ty: ops_try_ok_alias,
+                                associated_ty: ops_try_ok_alias.id,
                                 parameters: Substs::single(inner_ty),
                             },
                         };
diff --git a/crates/ra_hir/src/ty/lower.rs b/crates/ra_hir/src/ty/lower.rs
index eb51d31bd..d7d4bb0d6 100644
--- a/crates/ra_hir/src/ty/lower.rs
+++ b/crates/ra_hir/src/ty/lower.rs
@@ -176,7 +176,7 @@ impl Ty {
                         Some(associated_ty) => {
                             // FIXME handle type parameters on the segment
                             Ty::Projection(ProjectionTy {
-                                associated_ty,
+                                associated_ty: associated_ty.id,
                                 parameters: trait_ref.substs,
                             })
                         }
@@ -268,7 +268,10 @@ impl Ty {
                     .fill_with_unknown()
                     .build();
                 // FIXME handle type parameters on the segment
-                return Ty::Projection(ProjectionTy { associated_ty, parameters: substs });
+                return Ty::Projection(ProjectionTy {
+                    associated_ty: associated_ty.id,
+                    parameters: substs,
+                });
             }
         }
         Ty::Unknown
@@ -508,7 +511,7 @@ fn assoc_type_bindings_from_type_bound<'a>(
             let associated_ty =
                 match trait_ref.trait_.associated_type_by_name_including_super_traits(db, &name) {
                     None => return GenericPredicate::Error,
-                    Some(t) => t,
+                    Some(t) => t.id,
                 };
             let projection_ty =
                 ProjectionTy { associated_ty, parameters: trait_ref.substs.clone() };
diff --git a/crates/ra_hir/src/ty/traits.rs b/crates/ra_hir/src/ty/traits.rs
index 268fa09e4..b9a5d651f 100644
--- a/crates/ra_hir/src/ty/traits.rs
+++ b/crates/ra_hir/src/ty/traits.rs
@@ -2,13 +2,14 @@
 use std::sync::{Arc, Mutex};
 
 use chalk_ir::{cast::Cast, family::ChalkIr};
+use hir_def::DefWithBodyId;
 use log::debug;
 use ra_db::{impl_intern_key, salsa};
 use ra_prof::profile;
 use rustc_hash::FxHashSet;
 
 use super::{Canonical, GenericPredicate, HirDisplay, ProjectionTy, TraitRef, Ty, TypeWalk};
-use crate::{db::HirDatabase, expr::ExprId, Crate, DefWithBody, ImplBlock, Trait, TypeAlias};
+use crate::{db::HirDatabase, expr::ExprId, Crate, ImplBlock, Trait, TypeAlias};
 
 use self::chalk::{from_chalk, ToChalk};
 
@@ -290,7 +291,7 @@ impl FnTrait {
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct ClosureFnTraitImplData {
-    def: DefWithBody,
+    def: DefWithBodyId,
     expr: ExprId,
     fn_trait: FnTrait,
 }
diff --git a/crates/ra_hir/src/ty/traits/chalk.rs b/crates/ra_hir/src/ty/traits/chalk.rs
index 0272dd9ae..06388a3ce 100644
--- a/crates/ra_hir/src/ty/traits/chalk.rs
+++ b/crates/ra_hir/src/ty/traits/chalk.rs
@@ -9,7 +9,7 @@ use chalk_ir::{
 };
 use chalk_rust_ir::{AssociatedTyDatum, AssociatedTyValue, ImplDatum, StructDatum, TraitDatum};
 
-use hir_def::{lang_item::LangItemTarget, GenericDefId};
+use hir_def::{lang_item::LangItemTarget, ContainerId, GenericDefId, Lookup, TypeAliasId};
 use hir_expand::name;
 
 use ra_db::salsa::{InternId, InternKey};
@@ -203,15 +203,15 @@ impl ToChalk for Impl {
     }
 }
 
-impl ToChalk for TypeAlias {
+impl ToChalk for TypeAliasId {
     type Chalk = chalk_ir::TypeId;
 
     fn to_chalk(self, _db: &impl HirDatabase) -> chalk_ir::TypeId {
-        chalk_ir::TypeId(id_to_chalk(self.id))
+        chalk_ir::TypeId(id_to_chalk(self))
     }
 
-    fn from_chalk(_db: &impl HirDatabase, type_alias_id: chalk_ir::TypeId) -> TypeAlias {
-        TypeAlias { id: id_from_chalk(type_alias_id.0) }
+    fn from_chalk(_db: &impl HirDatabase, type_alias_id: chalk_ir::TypeId) -> TypeAliasId {
+        id_from_chalk(type_alias_id.0)
     }
 }
 
@@ -504,21 +504,21 @@ pub(crate) fn associated_ty_data_query(
     id: TypeId,
 ) -> Arc<AssociatedTyDatum<ChalkIr>> {
     debug!("associated_ty_data {:?}", id);
-    let type_alias: TypeAlias = from_chalk(db, id);
-    let trait_ = match type_alias.container(db) {
-        Some(crate::Container::Trait(t)) => t,
+    let type_alias: TypeAliasId = from_chalk(db, id);
+    let trait_ = match type_alias.lookup(db).container {
+        ContainerId::TraitId(t) => t,
         _ => panic!("associated type not in trait"),
     };
-    let generic_params = db.generic_params(type_alias.id.into());
+    let generic_params = db.generic_params(type_alias.into());
     let bound_data = chalk_rust_ir::AssociatedTyDatumBound {
         // FIXME add bounds and where clauses
         bounds: vec![],
         where_clauses: vec![],
     };
     let datum = AssociatedTyDatum {
-        trait_id: trait_.to_chalk(db),
+        trait_id: Trait::from(trait_).to_chalk(db),
         id,
-        name: lalrpop_intern::intern(&type_alias.name(db).to_string()),
+        name: lalrpop_intern::intern(&db.type_alias_data(type_alias).name.to_string()),
         binders: make_binders(bound_data, generic_params.count_params_including_parent()),
     };
     Arc::new(datum)
@@ -566,7 +566,7 @@ pub(crate) fn trait_datum_query(
         .items(db)
         .into_iter()
         .filter_map(|trait_item| match trait_item {
-            crate::AssocItem::TypeAlias(type_alias) => Some(type_alias),
+            crate::AssocItem::TypeAlias(type_alias) => Some(type_alias.id),
             _ => None,
         })
         .map(|type_alias| type_alias.to_chalk(db))
@@ -785,7 +785,8 @@ fn type_alias_associated_ty_value(
         .trait_;
     let assoc_ty = trait_
         .associated_type_by_name(db, &type_alias.name(db))
-        .expect("assoc ty value should not exist"); // validated when building the impl data as well
+        .expect("assoc ty value should not exist") // validated when building the impl data as well
+        .id;
     let generic_params = db.generic_params(impl_block.id.into());
     let bound_vars = Substs::bound_vars(&generic_params);
     let ty = db.type_for_def(type_alias.into(), crate::ty::Namespace::Types).subst(&bound_vars);
@@ -820,7 +821,8 @@ fn closure_fn_trait_output_assoc_ty_value(
 
     let output_ty_id = fn_once_trait
         .associated_type_by_name(db, &name::OUTPUT_TYPE)
-        .expect("assoc ty value should not exist");
+        .expect("assoc ty value should not exist")
+        .id;
 
     let value_bound = chalk_rust_ir::AssociatedTyValueBound { ty: output_ty.to_chalk(db) };