3 files changed, 59 insertions, 14 deletions

diff --git a/crates/ra_hir_ty/src/traits/chalk/interner.rs b/crates/ra_hir_ty/src/traits/chalk/interner.rs
index 060372819..2a27f8ed8 100644
--- a/crates/ra_hir_ty/src/traits/chalk/interner.rs
+++ b/crates/ra_hir_ty/src/traits/chalk/interner.rs
@@ -20,6 +20,8 @@ pub type ImplId = chalk_ir::ImplId<Interner>;
 pub type ImplDatum = chalk_rust_ir::ImplDatum<Interner>;
 pub type AssociatedTyValueId = chalk_rust_ir::AssociatedTyValueId<Interner>;
 pub type AssociatedTyValue = chalk_rust_ir::AssociatedTyValue<Interner>;
+pub type FnDefId = chalk_ir::FnDefId<Interner>;
+pub type FnDefDatum = chalk_rust_ir::FnDefDatum<Interner>;
 
 impl chalk_ir::interner::Interner for Interner {
     type InternedType = Box<chalk_ir::TyData<Self>>; // FIXME use Arc?
diff --git a/crates/ra_hir_ty/src/traits/chalk/mapping.rs b/crates/ra_hir_ty/src/traits/chalk/mapping.rs
index a83d82fd8..7082cb095 100644
--- a/crates/ra_hir_ty/src/traits/chalk/mapping.rs
+++ b/crates/ra_hir_ty/src/traits/chalk/mapping.rs
@@ -15,8 +15,8 @@ use crate::{
     db::HirDatabase,
     primitive::{FloatBitness, FloatTy, IntBitness, IntTy, Signedness, Uncertain},
     traits::{builtin, AssocTyValue, Canonical, Impl, Obligation},
-    ApplicationTy, GenericPredicate, InEnvironment, ProjectionPredicate, ProjectionTy, Substs,
-    TraitEnvironment, TraitRef, Ty, TypeCtor,
+    ApplicationTy, CallableDef, GenericPredicate, InEnvironment, ProjectionPredicate, ProjectionTy,
+    Substs, TraitEnvironment, TraitRef, Ty, TypeCtor,
 };
 
 use super::interner::*;
@@ -26,14 +26,19 @@ impl ToChalk for Ty {
     type Chalk = chalk_ir::Ty<Interner>;
     fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::Ty<Interner> {
         match self {
-            Ty::Apply(apply_ty) => {
-                if let TypeCtor::Ref(m) = apply_ty.ctor {
-                    return ref_to_chalk(db, m, apply_ty.parameters);
+            Ty::Apply(apply_ty) => match apply_ty.ctor {
+                TypeCtor::Ref(m) => ref_to_chalk(db, m, apply_ty.parameters),
+                TypeCtor::FnPtr { num_args: _ } => {
+                    let substitution = apply_ty.parameters.to_chalk(db).shifted_in(&Interner);
+                    chalk_ir::TyData::Function(chalk_ir::Fn { num_binders: 0, substitution })
+                        .intern(&Interner)
                 }
-                let name = apply_ty.ctor.to_chalk(db);
-                let substitution = apply_ty.parameters.to_chalk(db);
-                chalk_ir::ApplicationTy { name, substitution }.cast(&Interner).intern(&Interner)
-            }
+                _ => {
+                    let name = apply_ty.ctor.to_chalk(db);
+                    let substitution = apply_ty.parameters.to_chalk(db);
+                    chalk_ir::ApplicationTy { name, substitution }.cast(&Interner).intern(&Interner)
+                }
+            },
             Ty::Projection(proj_ty) => {
                 let associated_ty_id = proj_ty.associated_ty.to_chalk(db);
                 let substitution = proj_ty.parameters.to_chalk(db);
@@ -93,7 +98,13 @@ impl ToChalk for Ty {
                 Ty::Projection(ProjectionTy { associated_ty, parameters })
             }
             chalk_ir::TyData::Alias(chalk_ir::AliasTy::Opaque(_)) => unimplemented!(),
-            chalk_ir::TyData::Function(_) => unimplemented!(),
+            chalk_ir::TyData::Function(chalk_ir::Fn { num_binders: _, substitution }) => {
+                let parameters: Substs = from_chalk(db, substitution);
+                Ty::Apply(ApplicationTy {
+                    ctor: TypeCtor::FnPtr { num_args: (parameters.len() - 1) as u16 },
+                    parameters,
+                })
+            }
             chalk_ir::TyData::BoundVar(idx) => Ty::Bound(idx),
             chalk_ir::TyData::InferenceVar(_iv) => Ty::Unknown,
             chalk_ir::TyData::Dyn(where_clauses) => {
@@ -217,11 +228,14 @@ impl ToChalk for TypeCtor {
             TypeCtor::Slice => TypeName::Slice,
             TypeCtor::Ref(mutability) => TypeName::Ref(mutability.to_chalk(db)),
             TypeCtor::Str => TypeName::Str,
+            TypeCtor::FnDef(callable_def) => {
+                let id = callable_def.to_chalk(db);
+                TypeName::FnDef(id)
+            }
             TypeCtor::Int(Uncertain::Unknown)
             | TypeCtor::Float(Uncertain::Unknown)
             | TypeCtor::Adt(_)
             | TypeCtor::Array
-            | TypeCtor::FnDef(_)
             | TypeCtor::FnPtr { .. }
             | TypeCtor::Never
             | TypeCtor::Closure { .. } => {
@@ -260,7 +274,10 @@ impl ToChalk for TypeCtor {
             TypeName::Ref(mutability) => TypeCtor::Ref(from_chalk(db, mutability)),
             TypeName::Str => TypeCtor::Str,
 
-            TypeName::FnDef(_) => unreachable!(),
+            TypeName::FnDef(fn_def_id) => {
+                let callable_def = from_chalk(db, fn_def_id);
+                TypeCtor::FnDef(callable_def)
+            }
 
             TypeName::Error => {
                 // this should not be reached, since we don't represent TypeName::Error with TypeCtor
@@ -347,6 +364,18 @@ impl ToChalk for Impl {
     }
 }
 
+impl ToChalk for CallableDef {
+    type Chalk = FnDefId;
+
+    fn to_chalk(self, db: &dyn HirDatabase) -> FnDefId {
+        db.intern_callable_def(self).into()
+    }
+
+    fn from_chalk(db: &dyn HirDatabase, fn_def_id: FnDefId) -> CallableDef {
+        db.lookup_intern_callable_def(fn_def_id.into())
+    }
+}
+
 impl ToChalk for TypeAliasId {
     type Chalk = AssocTypeId;
 
diff --git a/crates/ra_hir_ty/src/traits/chalk/tls.rs b/crates/ra_hir_ty/src/traits/chalk/tls.rs
index ebf402a07..d88828c7c 100644
--- a/crates/ra_hir_ty/src/traits/chalk/tls.rs
+++ b/crates/ra_hir_ty/src/traits/chalk/tls.rs
@@ -247,10 +247,24 @@ impl DebugContext<'_> {
 
     pub fn debug_fn_def_id(
         &self,
-        _fn_def_id: chalk_ir::FnDefId<Interner>,
+        fn_def_id: chalk_ir::FnDefId<Interner>,
         fmt: &mut fmt::Formatter<'_>,
     ) -> Result<(), fmt::Error> {
-        write!(fmt, "fn")
+        let def: CallableDef = from_chalk(self.0, fn_def_id);
+        let name = match def {
+            CallableDef::FunctionId(ff) => self.0.function_data(ff).name.clone(),
+            CallableDef::StructId(s) => self.0.struct_data(s).name.clone(),
+            CallableDef::EnumVariantId(e) => {
+                let enum_data = self.0.enum_data(e.parent);
+                enum_data.variants[e.local_id].name.clone()
+            }
+        };
+        match def {
+            CallableDef::FunctionId(_) => write!(fmt, "{{fn {}}}", name),
+            CallableDef::StructId(_) | CallableDef::EnumVariantId(_) => {
+                write!(fmt, "{{ctor {}}}", name)
+            }
+        }
     }
 
     pub fn debug_const(