8 files changed, 75 insertions, 36 deletions

diff --git a/crates/ra_hir_ty/src/display.rs b/crates/ra_hir_ty/src/display.rs
index 9bb3ece6c..dcca1bace 100644
--- a/crates/ra_hir_ty/src/display.rs
+++ b/crates/ra_hir_ty/src/display.rs
@@ -10,6 +10,7 @@ pub struct HirFormatter<'a, 'b, DB> {
     buf: String,
     curr_size: usize,
     max_size: Option<usize>,
+    should_display_default_types: bool,
 }
 
 pub trait HirDisplay {
@@ -19,7 +20,7 @@ pub trait HirDisplay {
     where
         Self: Sized,
     {
-        HirDisplayWrapper(db, self, None)
+        HirDisplayWrapper(db, self, None, true)
     }
 
     fn display_truncated<'a, DB>(
@@ -30,7 +31,7 @@ pub trait HirDisplay {
     where
         Self: Sized,
     {
-        HirDisplayWrapper(db, self, max_size)
+        HirDisplayWrapper(db, self, max_size, false)
     }
 }
 
@@ -72,9 +73,13 @@ where
             false
         }
     }
+
+    pub fn should_display_default_types(&self) -> bool {
+        self.should_display_default_types
+    }
 }
 
-pub struct HirDisplayWrapper<'a, DB, T>(&'a DB, &'a T, Option<usize>);
+pub struct HirDisplayWrapper<'a, DB, T>(&'a DB, &'a T, Option<usize>, bool);
 
 impl<'a, DB, T> fmt::Display for HirDisplayWrapper<'a, DB, T>
 where
@@ -88,6 +93,7 @@ where
             buf: String::with_capacity(20),
             curr_size: 0,
             max_size: self.2,
+            should_display_default_types: self.3,
         })
     }
 }
diff --git a/crates/ra_hir_ty/src/infer/expr.rs b/crates/ra_hir_ty/src/infer/expr.rs
index 011c6c5c6..8be567917 100644
--- a/crates/ra_hir_ty/src/infer/expr.rs
+++ b/crates/ra_hir_ty/src/infer/expr.rs
@@ -8,7 +8,7 @@ use hir_def::{
     expr::{Array, BinaryOp, Expr, ExprId, Literal, Statement, UnaryOp},
     path::{GenericArg, GenericArgs},
     resolver::resolver_for_expr,
-    AdtId, ContainerId, Lookup, StructFieldId,
+    AdtId, AssocContainerId, Lookup, StructFieldId,
 };
 use hir_expand::name::{name, Name};
 use ra_syntax::ast::RangeOp;
@@ -676,7 +676,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 // add obligation for trait implementation, if this is a trait method
                 match def {
                     CallableDef::FunctionId(f) => {
-                        if let ContainerId::TraitId(trait_) = f.lookup(self.db).container {
+                        if let AssocContainerId::TraitId(trait_) = f.lookup(self.db).container {
                             // construct a TraitDef
                             let substs =
                                 a_ty.parameters.prefix(generics(self.db, trait_.into()).len());
diff --git a/crates/ra_hir_ty/src/infer/path.rs b/crates/ra_hir_ty/src/infer/path.rs
index 3bae0ca6c..ffd358367 100644
--- a/crates/ra_hir_ty/src/infer/path.rs
+++ b/crates/ra_hir_ty/src/infer/path.rs
@@ -3,9 +3,9 @@
 use std::iter;
 
 use hir_def::{
-    path::{Path, PathKind, PathSegment},
+    path::{Path, PathSegment},
     resolver::{ResolveValueResult, Resolver, TypeNs, ValueNs},
-    AssocItemId, ContainerId, Lookup,
+    AssocContainerId, AssocItemId, Lookup,
 };
 use hir_expand::name::Name;
 
@@ -32,7 +32,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         path: &Path,
         id: ExprOrPatId,
     ) -> Option<Ty> {
-        let (value, self_subst) = if let PathKind::Type(type_ref) = path.kind() {
+        let (value, self_subst) = if let Some(type_ref) = path.type_anchor() {
             if path.segments().is_empty() {
                 // This can't actually happen syntax-wise
                 return None;
@@ -209,7 +209,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                     AssocItemId::TypeAliasId(_) => unreachable!(),
                 };
                 let substs = match container {
-                    ContainerId::ImplId(impl_id) => {
+                    AssocContainerId::ImplId(impl_id) => {
                         let impl_substs = Substs::build_for_def(self.db, impl_id)
                             .fill(iter::repeat_with(|| self.table.new_type_var()))
                             .build();
@@ -221,7 +221,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                         self.unify(&impl_self_ty, &ty);
                         Some(substs)
                     }
-                    ContainerId::TraitId(trait_) => {
+                    AssocContainerId::TraitId(trait_) => {
                         // we're picking this method
                         let trait_substs = Substs::build_for_def(self.db, trait_)
                             .push(ty.clone())
@@ -237,7 +237,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                         }));
                         Some(substs)
                     }
-                    ContainerId::ModuleId(_) => None,
+                    AssocContainerId::ContainerId(_) => None,
                 };
 
                 self.write_assoc_resolution(id, item.into());
diff --git a/crates/ra_hir_ty/src/lib.rs b/crates/ra_hir_ty/src/lib.rs
index 3ad913e55..7310ef10d 100644
--- a/crates/ra_hir_ty/src/lib.rs
+++ b/crates/ra_hir_ty/src/lib.rs
@@ -44,8 +44,8 @@ use std::sync::Arc;
 use std::{fmt, iter, mem};
 
 use hir_def::{
-    expr::ExprId, type_ref::Mutability, AdtId, ContainerId, DefWithBodyId, GenericDefId, HasModule,
-    Lookup, TraitId, TypeAliasId,
+    expr::ExprId, type_ref::Mutability, AdtId, AssocContainerId, DefWithBodyId, GenericDefId,
+    HasModule, Lookup, TraitId, TypeAliasId,
 };
 use hir_expand::name::Name;
 use ra_db::{impl_intern_key, salsa, CrateId};
@@ -251,7 +251,7 @@ impl ProjectionTy {
 
     fn trait_(&self, db: &impl HirDatabase) -> TraitId {
         match self.associated_ty.lookup(db).container {
-            ContainerId::TraitId(it) => it,
+            AssocContainerId::TraitId(it) => it,
             _ => panic!("projection ty without parent trait"),
         }
     }
@@ -906,13 +906,44 @@ impl HirDisplay for ApplicationTy {
                 write!(f, "{}", name)?;
                 if self.parameters.len() > 0 {
                     write!(f, "<")?;
-                    f.write_joined(&*self.parameters.0, ", ")?;
+
+                    let mut non_default_parameters = Vec::with_capacity(self.parameters.len());
+                    let parameters_to_write = if f.should_display_default_types() {
+                        self.parameters.0.as_ref()
+                    } else {
+                        match self
+                            .ctor
+                            .as_generic_def()
+                            .map(|generic_def_id| f.db.generic_defaults(generic_def_id))
+                            .filter(|defaults| !defaults.is_empty())
+                        {
+                            Option::None => self.parameters.0.as_ref(),
+                            Option::Some(default_parameters) => {
+                                for (i, parameter) in self.parameters.into_iter().enumerate() {
+                                    match (parameter, default_parameters.get(i)) {
+                                        (&Ty::Unknown, _) | (_, None) => {
+                                            non_default_parameters.push(parameter.clone())
+                                        }
+                                        (_, Some(default_parameter))
+                                            if parameter != default_parameter =>
+                                        {
+                                            non_default_parameters.push(parameter.clone())
+                                        }
+                                        _ => (),
+                                    }
+                                }
+                                &non_default_parameters
+                            }
+                        }
+                    };
+
+                    f.write_joined(parameters_to_write, ", ")?;
                     write!(f, ">")?;
                 }
             }
             TypeCtor::AssociatedType(type_alias) => {
                 let trait_ = match type_alias.lookup(f.db).container {
-                    ContainerId::TraitId(it) => it,
+                    AssocContainerId::TraitId(it) => it,
                     _ => panic!("not an associated type"),
                 };
                 let trait_name = f.db.trait_data(trait_).name.clone();
diff --git a/crates/ra_hir_ty/src/lower.rs b/crates/ra_hir_ty/src/lower.rs
index a4ddfc8ef..af3db2e1d 100644
--- a/crates/ra_hir_ty/src/lower.rs
+++ b/crates/ra_hir_ty/src/lower.rs
@@ -11,7 +11,7 @@ use std::sync::Arc;
 use hir_def::{
     builtin_type::BuiltinType,
     generics::WherePredicate,
-    path::{GenericArg, Path, PathKind, PathSegment, PathSegments},
+    path::{GenericArg, Path, PathSegment, PathSegments},
     resolver::{HasResolver, Resolver, TypeNs},
     type_ref::{TypeBound, TypeRef},
     AdtId, ConstId, EnumId, EnumVariantId, FunctionId, GenericDefId, HasModule, ImplId,
@@ -101,7 +101,7 @@ impl Ty {
             TypeRef::Path(path) => path,
             _ => return None,
         };
-        if let PathKind::Type(_) = path.kind() {
+        if path.type_anchor().is_some() {
             return None;
         }
         if path.segments().len() > 1 {
@@ -202,7 +202,7 @@ impl Ty {
 
     pub(crate) fn from_hir_path(db: &impl HirDatabase, resolver: &Resolver, path: &Path) -> Ty {
         // Resolve the path (in type namespace)
-        if let PathKind::Type(type_ref) = path.kind() {
+        if let Some(type_ref) = path.type_anchor() {
             let ty = Ty::from_hir(db, resolver, &type_ref);
             return Ty::from_type_relative_path(db, resolver, ty, path.segments());
         }
@@ -697,8 +697,8 @@ impl CallableDef {
     pub fn krate(self, db: &impl HirDatabase) -> CrateId {
         match self {
             CallableDef::FunctionId(f) => f.lookup(db).module(db),
-            CallableDef::StructId(s) => s.lookup(db).container,
-            CallableDef::EnumVariantId(e) => e.parent.lookup(db).container,
+            CallableDef::StructId(s) => s.lookup(db).container.module(db),
+            CallableDef::EnumVariantId(e) => e.parent.lookup(db).container.module(db),
         }
         .krate
     }
diff --git a/crates/ra_hir_ty/src/method_resolution.rs b/crates/ra_hir_ty/src/method_resolution.rs
index 848e306e9..92fb4c081 100644
--- a/crates/ra_hir_ty/src/method_resolution.rs
+++ b/crates/ra_hir_ty/src/method_resolution.rs
@@ -6,8 +6,8 @@ use std::sync::Arc;
 
 use arrayvec::ArrayVec;
 use hir_def::{
-    lang_item::LangItemTarget, resolver::Resolver, type_ref::Mutability, AssocItemId, FunctionId,
-    HasModule, ImplId, Lookup, TraitId,
+    lang_item::LangItemTarget, resolver::Resolver, type_ref::Mutability, AssocContainerId,
+    AssocItemId, FunctionId, HasModule, ImplId, Lookup, TraitId,
 };
 use hir_expand::name::Name;
 use ra_db::CrateId;
@@ -134,7 +134,7 @@ impl Ty {
                 LangItemTarget::ImplBlockId(it) => Some(it),
                 _ => None,
             })
-            .map(|it| it.lookup(db).container.krate)
+            .map(|it| it.lookup(db).container.module(db).krate)
             .collect();
         Some(res)
     }
@@ -451,12 +451,12 @@ fn transform_receiver_ty(
     self_ty: &Canonical<Ty>,
 ) -> Option<Ty> {
     let substs = match function_id.lookup(db).container {
-        hir_def::ContainerId::TraitId(_) => Substs::build_for_def(db, function_id)
+        AssocContainerId::TraitId(_) => Substs::build_for_def(db, function_id)
             .push(self_ty.value.clone())
             .fill_with_unknown()
             .build(),
-        hir_def::ContainerId::ImplId(impl_id) => inherent_impl_substs(db, impl_id, &self_ty)?,
-        hir_def::ContainerId::ModuleId(_) => unreachable!(),
+        AssocContainerId::ImplId(impl_id) => inherent_impl_substs(db, impl_id, &self_ty)?,
+        AssocContainerId::ContainerId(_) => unreachable!(),
     };
     let sig = db.callable_item_signature(function_id.into());
     Some(sig.params()[0].clone().subst(&substs))
diff --git a/crates/ra_hir_ty/src/traits/chalk.rs b/crates/ra_hir_ty/src/traits/chalk.rs
index fc21872b2..5eb032d86 100644
--- a/crates/ra_hir_ty/src/traits/chalk.rs
+++ b/crates/ra_hir_ty/src/traits/chalk.rs
@@ -9,7 +9,9 @@ use chalk_ir::{
 };
 use chalk_rust_ir::{AssociatedTyDatum, AssociatedTyValue, ImplDatum, StructDatum, TraitDatum};
 
-use hir_def::{AssocItemId, ContainerId, GenericDefId, ImplId, Lookup, TraitId, TypeAliasId};
+use hir_def::{
+    AssocContainerId, AssocItemId, GenericDefId, HasModule, ImplId, Lookup, TraitId, TypeAliasId,
+};
 use ra_db::{
     salsa::{InternId, InternKey},
     CrateId,
@@ -542,7 +544,7 @@ pub(crate) fn associated_ty_data_query(
     debug!("associated_ty_data {:?}", id);
     let type_alias: TypeAliasId = from_chalk(db, id);
     let trait_ = match type_alias.lookup(db).container {
-        ContainerId::TraitId(t) => t,
+        AssocContainerId::TraitId(t) => t,
         _ => panic!("associated type not in trait"),
     };
     let generic_params = generics(db, type_alias.into());
@@ -591,7 +593,7 @@ pub(crate) fn trait_datum_query(
     let bound_vars = Substs::bound_vars(&generic_params);
     let flags = chalk_rust_ir::TraitFlags {
         auto: trait_data.auto,
-        upstream: trait_.lookup(db).container.krate != krate,
+        upstream: trait_.lookup(db).container.module(db).krate != krate,
         non_enumerable: true,
         coinductive: false, // only relevant for Chalk testing
         // FIXME set these flags correctly
@@ -671,7 +673,7 @@ fn impl_block_datum(
     let bound_vars = Substs::bound_vars(&generic_params);
     let trait_ref = trait_ref.subst(&bound_vars);
     let trait_ = trait_ref.trait_;
-    let impl_type = if impl_id.lookup(db).container.krate == krate {
+    let impl_type = if impl_id.lookup(db).container.module(db).krate == krate {
         chalk_rust_ir::ImplType::Local
     } else {
         chalk_rust_ir::ImplType::External
@@ -755,7 +757,7 @@ fn type_alias_associated_ty_value(
 ) -> Arc<AssociatedTyValue<ChalkIr>> {
     let type_alias_data = db.type_alias_data(type_alias);
     let impl_id = match type_alias.lookup(db).container {
-        ContainerId::ImplId(it) => it,
+        AssocContainerId::ImplId(it) => it,
         _ => panic!("assoc ty value should be in impl"),
     };
 
diff --git a/crates/ra_hir_ty/src/utils.rs b/crates/ra_hir_ty/src/utils.rs
index 29799a8cb..0b1806a84 100644
--- a/crates/ra_hir_ty/src/utils.rs
+++ b/crates/ra_hir_ty/src/utils.rs
@@ -9,7 +9,7 @@ use hir_def::{
     path::Path,
     resolver::{HasResolver, TypeNs},
     type_ref::TypeRef,
-    ContainerId, GenericDefId, Lookup, TraitId, TypeAliasId, TypeParamId, VariantId,
+    AssocContainerId, GenericDefId, Lookup, TraitId, TypeAliasId, TypeParamId, VariantId,
 };
 use hir_expand::name::{name, Name};
 
@@ -155,8 +155,8 @@ fn parent_generic_def(db: &impl DefDatabase, def: GenericDefId) -> Option<Generi
     };
 
     match container {
-        ContainerId::ImplId(it) => Some(it.into()),
-        ContainerId::TraitId(it) => Some(it.into()),
-        ContainerId::ModuleId(_) => None,
+        AssocContainerId::ImplId(it) => Some(it.into()),
+        AssocContainerId::TraitId(it) => Some(it.into()),
+        AssocContainerId::ContainerId(_) => None,
     }
 }