1 files changed, 122 insertions, 115 deletions

diff --git a/crates/hir_ty/src/display.rs b/crates/hir_ty/src/display.rs
index d2f1b4014..d4a8b48e6 100644
--- a/crates/hir_ty/src/display.rs
+++ b/crates/hir_ty/src/display.rs
@@ -3,10 +3,12 @@
 use std::{borrow::Cow, fmt};
 
 use crate::{
-    db::HirDatabase, utils::generics, ApplicationTy, CallableDefId, FnSig, GenericPredicate,
-    Lifetime, Obligation, OpaqueTy, OpaqueTyId, ProjectionTy, Substs, TraitRef, Ty, TypeCtor,
+    db::HirDatabase, primitive, utils::generics, AliasTy, CallableDefId, CallableSig,
+    GenericPredicate, Lifetime, Obligation, OpaqueTy, OpaqueTyId, ProjectionTy, Scalar, Substs,
+    TraitRef, Ty,
 };
 use arrayvec::ArrayVec;
+use chalk_ir::Mutability;
 use hir_def::{
     db::DefDatabase, find_path, generics::TypeParamProvenance, item_scope::ItemInNs, AdtId,
     AssocContainerId, HasModule, Lookup, ModuleId, TraitId,
@@ -234,39 +236,79 @@ impl HirDisplay for &Ty {
     }
 }
 
-impl HirDisplay for ApplicationTy {
+impl HirDisplay for ProjectionTy {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+        if f.should_truncate() {
+            return write!(f, "{}", TYPE_HINT_TRUNCATION);
+        }
+
+        let trait_ = f.db.trait_data(self.trait_(f.db));
+        let first_parameter = self.parameters[0].into_displayable(
+            f.db,
+            f.max_size,
+            f.omit_verbose_types,
+            f.display_target,
+        );
+        write!(f, "<{} as {}", first_parameter, trait_.name)?;
+        if self.parameters.len() > 1 {
+            write!(f, "<")?;
+            f.write_joined(&self.parameters[1..], ", ")?;
+            write!(f, ">")?;
+        }
+        write!(f, ">::{}", f.db.type_alias_data(self.associated_ty).name)?;
+        Ok(())
+    }
+}
+
+impl HirDisplay for Ty {
     fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
         if f.should_truncate() {
             return write!(f, "{}", TYPE_HINT_TRUNCATION);
         }
 
-        match self.ctor {
-            TypeCtor::Bool => write!(f, "bool")?,
-            TypeCtor::Char => write!(f, "char")?,
-            TypeCtor::Int(t) => write!(f, "{}", t)?,
-            TypeCtor::Float(t) => write!(f, "{}", t)?,
-            TypeCtor::Str => write!(f, "str")?,
-            TypeCtor::Slice => {
-                let t = self.parameters.as_single();
+        match self {
+            Ty::Never => write!(f, "!")?,
+            Ty::Str => write!(f, "str")?,
+            Ty::Scalar(Scalar::Bool) => write!(f, "bool")?,
+            Ty::Scalar(Scalar::Char) => write!(f, "char")?,
+            &Ty::Scalar(Scalar::Float(t)) => write!(f, "{}", primitive::float_ty_to_string(t))?,
+            &Ty::Scalar(Scalar::Int(t)) => write!(f, "{}", primitive::int_ty_to_string(t))?,
+            &Ty::Scalar(Scalar::Uint(t)) => write!(f, "{}", primitive::uint_ty_to_string(t))?,
+            Ty::Slice(parameters) => {
+                let t = parameters.as_single();
                 write!(f, "[")?;
                 t.hir_fmt(f)?;
                 write!(f, "]")?;
             }
-            TypeCtor::Array => {
-                let t = self.parameters.as_single();
+            Ty::Array(parameters) => {
+                let t = parameters.as_single();
                 write!(f, "[")?;
                 t.hir_fmt(f)?;
                 write!(f, "; _]")?;
             }
-            TypeCtor::RawPtr(m) | TypeCtor::Ref(m) => {
-                let t = self.parameters.as_single();
+            Ty::Raw(m, parameters) | Ty::Ref(m, parameters) => {
+                let t = parameters.as_single();
                 let ty_display =
                     t.into_displayable(f.db, f.max_size, f.omit_verbose_types, f.display_target);
 
-                if matches!(self.ctor, TypeCtor::RawPtr(_)) {
-                    write!(f, "*{}", m.as_keyword_for_ptr())?;
+                if matches!(self, Ty::Raw(..)) {
+                    write!(
+                        f,
+                        "*{}",
+                        match m {
+                            Mutability::Not => "const ",
+                            Mutability::Mut => "mut ",
+                        }
+                    )?;
                 } else {
-                    write!(f, "&{}", m.as_keyword_for_ref())?;
+                    write!(
+                        f,
+                        "&{}",
+                        match m {
+                            Mutability::Not => "",
+                            Mutability::Mut => "mut ",
+                        }
+                    )?;
                 }
 
                 let datas;
@@ -274,10 +316,10 @@ impl HirDisplay for ApplicationTy {
                     Ty::Dyn(predicates) if predicates.len() > 1 => {
                         Cow::Borrowed(predicates.as_ref())
                     }
-                    &Ty::Opaque(OpaqueTy {
+                    &Ty::Alias(AliasTy::Opaque(OpaqueTy {
                         opaque_ty_id: OpaqueTyId::ReturnTypeImplTrait(func, idx),
                         ref parameters,
-                    }) => {
+                    })) => {
                         datas =
                             f.db.return_type_impl_traits(func).expect("impl trait id without data");
                         let data = (*datas)
@@ -304,25 +346,24 @@ impl HirDisplay for ApplicationTy {
                     write!(f, "{}", ty_display)?;
                 }
             }
-            TypeCtor::Never => write!(f, "!")?,
-            TypeCtor::Tuple { .. } => {
-                let ts = &self.parameters;
-                if ts.len() == 1 {
+            Ty::Tuple(_, substs) => {
+                if substs.len() == 1 {
                     write!(f, "(")?;
-                    ts[0].hir_fmt(f)?;
+                    substs[0].hir_fmt(f)?;
                     write!(f, ",)")?;
                 } else {
                     write!(f, "(")?;
-                    f.write_joined(&*ts.0, ", ")?;
+                    f.write_joined(&*substs.0, ", ")?;
                     write!(f, ")")?;
                 }
             }
-            TypeCtor::FnPtr { is_varargs, .. } => {
-                let sig = FnSig::from_fn_ptr_substs(&self.parameters, is_varargs);
+            Ty::Function(fn_ptr) => {
+                let sig = CallableSig::from_fn_ptr(fn_ptr);
                 sig.hir_fmt(f)?;
             }
-            TypeCtor::FnDef(def) => {
-                let sig = f.db.callable_item_signature(def).subst(&self.parameters);
+            Ty::FnDef(def, parameters) => {
+                let def = *def;
+                let sig = f.db.callable_item_signature(def).subst(parameters);
                 match def {
                     CallableDefId::FunctionId(ff) => {
                         write!(f, "fn {}", f.db.function_data(ff).name)?
@@ -332,7 +373,7 @@ impl HirDisplay for ApplicationTy {
                         write!(f, "{}", f.db.enum_data(e.parent).variants[e.local_id].name)?
                     }
                 };
-                if self.parameters.len() > 0 {
+                if parameters.len() > 0 {
                     let generics = generics(f.db.upcast(), def.into());
                     let (parent_params, self_param, type_params, _impl_trait_params) =
                         generics.provenance_split();
@@ -340,7 +381,7 @@ impl HirDisplay for ApplicationTy {
                     // We print all params except implicit impl Trait params. Still a bit weird; should we leave out parent and self?
                     if total_len > 0 {
                         write!(f, "<")?;
-                        f.write_joined(&self.parameters.0[..total_len], ", ")?;
+                        f.write_joined(&parameters.0[..total_len], ", ")?;
                         write!(f, ">")?;
                     }
                 }
@@ -359,10 +400,10 @@ impl HirDisplay for ApplicationTy {
                     write!(f, " -> {}", ret_display)?;
                 }
             }
-            TypeCtor::Adt(def_id) => {
+            Ty::Adt(def_id, parameters) => {
                 match f.display_target {
                     DisplayTarget::Diagnostics | DisplayTarget::Test => {
-                        let name = match def_id {
+                        let name = match *def_id {
                             AdtId::StructId(it) => f.db.struct_data(it).name.clone(),
                             AdtId::UnionId(it) => f.db.union_data(it).name.clone(),
                             AdtId::EnumId(it) => f.db.enum_data(it).name.clone(),
@@ -372,7 +413,7 @@ impl HirDisplay for ApplicationTy {
                     DisplayTarget::SourceCode { module_id } => {
                         if let Some(path) = find_path::find_path(
                             f.db.upcast(),
-                            ItemInNs::Types(def_id.into()),
+                            ItemInNs::Types((*def_id).into()),
                             module_id,
                         ) {
                             write!(f, "{}", path)?;
@@ -384,19 +425,18 @@ impl HirDisplay for ApplicationTy {
                     }
                 }
 
-                if self.parameters.len() > 0 {
+                if parameters.len() > 0 {
                     let parameters_to_write =
                         if f.display_target.is_source_code() || f.omit_verbose_types() {
                             match self
-                                .ctor
                                 .as_generic_def()
                                 .map(|generic_def_id| f.db.generic_defaults(generic_def_id))
                                 .filter(|defaults| !defaults.is_empty())
                             {
-                                None => self.parameters.0.as_ref(),
+                                None => parameters.0.as_ref(),
                                 Some(default_parameters) => {
                                     let mut default_from = 0;
-                                    for (i, parameter) in self.parameters.iter().enumerate() {
+                                    for (i, parameter) in parameters.iter().enumerate() {
                                         match (parameter, default_parameters.get(i)) {
                                             (&Ty::Unknown, _) | (_, None) => {
                                                 default_from = i + 1;
@@ -404,18 +444,18 @@ impl HirDisplay for ApplicationTy {
                                             (_, Some(default_parameter)) => {
                                                 let actual_default = default_parameter
                                                     .clone()
-                                                    .subst(&self.parameters.prefix(i));
+                                                    .subst(&parameters.prefix(i));
                                                 if parameter != &actual_default {
                                                     default_from = i + 1;
                                                 }
                                             }
                                         }
                                     }
-                                    &self.parameters.0[0..default_from]
+                                    &parameters.0[0..default_from]
                                 }
                             }
                         } else {
-                            self.parameters.0.as_ref()
+                            parameters.0.as_ref()
                         };
                     if !parameters_to_write.is_empty() {
                         write!(f, "<")?;
@@ -424,62 +464,54 @@ impl HirDisplay for ApplicationTy {
                     }
                 }
             }
-            TypeCtor::AssociatedType(type_alias) => {
+            Ty::AssociatedType(type_alias, parameters) => {
                 let trait_ = match type_alias.lookup(f.db.upcast()).container {
                     AssocContainerId::TraitId(it) => it,
                     _ => panic!("not an associated type"),
                 };
                 let trait_ = f.db.trait_data(trait_);
-                let type_alias_data = f.db.type_alias_data(type_alias);
+                let type_alias_data = f.db.type_alias_data(*type_alias);
 
                 // Use placeholder associated types when the target is test (https://rust-lang.github.io/chalk/book/clauses/type_equality.html#placeholder-associated-types)
                 if f.display_target.is_test() {
                     write!(f, "{}::{}", trait_.name, type_alias_data.name)?;
-                    if self.parameters.len() > 0 {
+                    if parameters.len() > 0 {
                         write!(f, "<")?;
-                        f.write_joined(&*self.parameters.0, ", ")?;
+                        f.write_joined(&*parameters.0, ", ")?;
                         write!(f, ">")?;
                     }
                 } else {
-                    let projection_ty = ProjectionTy {
-                        associated_ty: type_alias,
-                        parameters: self.parameters.clone(),
-                    };
+                    let projection_ty =
+                        ProjectionTy { associated_ty: *type_alias, parameters: parameters.clone() };
 
                     projection_ty.hir_fmt(f)?;
                 }
             }
-            TypeCtor::ForeignType(type_alias) => {
-                let type_alias = f.db.type_alias_data(type_alias);
+            Ty::ForeignType(type_alias) => {
+                let type_alias = f.db.type_alias_data(*type_alias);
                 write!(f, "{}", type_alias.name)?;
-                if self.parameters.len() > 0 {
-                    write!(f, "<")?;
-                    f.write_joined(&*self.parameters.0, ", ")?;
-                    write!(f, ">")?;
-                }
             }
-            TypeCtor::OpaqueType(opaque_ty_id) => {
+            Ty::OpaqueType(opaque_ty_id, parameters) => {
                 match opaque_ty_id {
-                    OpaqueTyId::ReturnTypeImplTrait(func, idx) => {
+                    &OpaqueTyId::ReturnTypeImplTrait(func, idx) => {
                         let datas =
                             f.db.return_type_impl_traits(func).expect("impl trait id without data");
                         let data = (*datas)
                             .as_ref()
                             .map(|rpit| rpit.impl_traits[idx as usize].bounds.clone());
-                        let bounds = data.subst(&self.parameters);
-                        write!(f, "impl ")?;
-                        write_bounds_like_dyn_trait(&bounds.value, f)?;
+                        let bounds = data.subst(&parameters);
+                        write_bounds_like_dyn_trait_with_prefix("impl", &bounds.value, f)?;
                         // FIXME: it would maybe be good to distinguish this from the alias type (when debug printing), and to show the substitution
                     }
                     OpaqueTyId::AsyncBlockTypeImplTrait(..) => {
                         write!(f, "impl Future<Output = ")?;
-                        self.parameters[0].hir_fmt(f)?;
+                        parameters[0].hir_fmt(f)?;
                         write!(f, ">")?;
                     }
                 }
             }
-            TypeCtor::Closure { .. } => {
-                let sig = self.parameters[0].callable_sig(f.db);
+            Ty::Closure(.., substs) => {
+                let sig = substs[0].callable_sig(f.db);
                 if let Some(sig) = sig {
                     if sig.params().is_empty() {
                         write!(f, "||")?;
@@ -502,44 +534,6 @@ impl HirDisplay for ApplicationTy {
                     write!(f, "{{closure}}")?;
                 }
             }
-        }
-        Ok(())
-    }
-}
-
-impl HirDisplay for ProjectionTy {
-    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
-        if f.should_truncate() {
-            return write!(f, "{}", TYPE_HINT_TRUNCATION);
-        }
-
-        let trait_ = f.db.trait_data(self.trait_(f.db));
-        let first_parameter = self.parameters[0].into_displayable(
-            f.db,
-            f.max_size,
-            f.omit_verbose_types,
-            f.display_target,
-        );
-        write!(f, "<{} as {}", first_parameter, trait_.name)?;
-        if self.parameters.len() > 1 {
-            write!(f, "<")?;
-            f.write_joined(&self.parameters[1..], ", ")?;
-            write!(f, ">")?;
-        }
-        write!(f, ">::{}", f.db.type_alias_data(self.associated_ty).name)?;
-        Ok(())
-    }
-}
-
-impl HirDisplay for Ty {
-    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
-        if f.should_truncate() {
-            return write!(f, "{}", TYPE_HINT_TRUNCATION);
-        }
-
-        match self {
-            Ty::Apply(a_ty) => a_ty.hir_fmt(f)?,
-            Ty::Projection(p_ty) => p_ty.hir_fmt(f)?,
             Ty::Placeholder(id) => {
                 let generics = generics(f.db.upcast(), id.parent);
                 let param_data = &generics.params.types[id.local_id];
@@ -548,22 +542,22 @@ impl HirDisplay for Ty {
                         write!(f, "{}", param_data.name.clone().unwrap_or_else(Name::missing))?
                     }
                     TypeParamProvenance::ArgumentImplTrait => {
-                        write!(f, "impl ")?;
                         let bounds = f.db.generic_predicates_for_param(*id);
                         let substs = Substs::type_params_for_generics(&generics);
-                        write_bounds_like_dyn_trait(
+                        write_bounds_like_dyn_trait_with_prefix(
+                            "impl",
                             &bounds.iter().map(|b| b.clone().subst(&substs)).collect::<Vec<_>>(),
                             f,
                         )?;
                     }
                 }
             }
-            Ty::Bound(idx) => write!(f, "?{}.{}", idx.debruijn.depth(), idx.index)?,
+            Ty::BoundVar(idx) => write!(f, "?{}.{}", idx.debruijn.depth(), idx.index)?,
             Ty::Dyn(predicates) => {
-                write!(f, "dyn ")?;
-                write_bounds_like_dyn_trait(predicates, f)?;
+                write_bounds_like_dyn_trait_with_prefix("dyn", predicates, f)?;
             }
-            Ty::Opaque(opaque_ty) => {
+            Ty::Alias(AliasTy::Projection(p_ty)) => p_ty.hir_fmt(f)?,
+            Ty::Alias(AliasTy::Opaque(opaque_ty)) => {
                 match opaque_ty.opaque_ty_id {
                     OpaqueTyId::ReturnTypeImplTrait(func, idx) => {
                         let datas =
@@ -572,8 +566,7 @@ impl HirDisplay for Ty {
                             .as_ref()
                             .map(|rpit| rpit.impl_traits[idx as usize].bounds.clone());
                         let bounds = data.subst(&opaque_ty.parameters);
-                        write!(f, "impl ")?;
-                        write_bounds_like_dyn_trait(&bounds.value, f)?;
+                        write_bounds_like_dyn_trait_with_prefix("impl", &bounds.value, f)?;
                     }
                     OpaqueTyId::AsyncBlockTypeImplTrait(..) => {
                         write!(f, "{{async block}}")?;
@@ -588,13 +581,13 @@ impl HirDisplay for Ty {
                 }
                 write!(f, "{{unknown}}")?;
             }
-            Ty::Infer(..) => write!(f, "_")?,
+            Ty::InferenceVar(..) => write!(f, "_")?,
         }
         Ok(())
     }
 }
 
-impl HirDisplay for FnSig {
+impl HirDisplay for CallableSig {
     fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
         write!(f, "fn(")?;
         f.write_joined(self.params(), ", ")?;
@@ -617,7 +610,7 @@ impl HirDisplay for FnSig {
 }
 
 fn fn_traits(db: &dyn DefDatabase, trait_: TraitId) -> impl Iterator<Item = TraitId> {
-    let krate = trait_.lookup(db).container.module(db).krate;
+    let krate = trait_.lookup(db).container.module(db).krate();
     let fn_traits = [
         db.lang_item(krate, "fn".into()),
         db.lang_item(krate, "fn_mut".into()),
@@ -627,7 +620,21 @@ fn fn_traits(db: &dyn DefDatabase, trait_: TraitId) -> impl Iterator<Item = Trai
     ArrayVec::from(fn_traits).into_iter().flatten().flat_map(|it| it.as_trait())
 }
 
-pub fn write_bounds_like_dyn_trait(
+pub fn write_bounds_like_dyn_trait_with_prefix(
+    prefix: &str,
+    predicates: &[GenericPredicate],
+    f: &mut HirFormatter,
+) -> Result<(), HirDisplayError> {
+    write!(f, "{}", prefix)?;
+    if !predicates.is_empty() {
+        write!(f, " ")?;
+        write_bounds_like_dyn_trait(predicates, f)
+    } else {
+        Ok(())
+    }
+}
+
+fn write_bounds_like_dyn_trait(
     predicates: &[GenericPredicate],
     f: &mut HirFormatter,
 ) -> Result<(), HirDisplayError> {