5 files changed, 38 insertions, 67 deletions

diff --git a/crates/ra_ide_api/src/completion/complete_dot.rs b/crates/ra_ide_api/src/completion/complete_dot.rs
index 5a3f9b5f6..b6fe48627 100644
--- a/crates/ra_ide_api/src/completion/complete_dot.rs
+++ b/crates/ra_ide_api/src/completion/complete_dot.rs
@@ -1,6 +1,6 @@
 //! FIXME: write short doc here
 
-use hir::{Adt, Ty, TypeCtor};
+use hir::Type;
 
 use crate::completion::completion_item::CompletionKind;
 use crate::{
@@ -22,12 +22,12 @@ pub(super) fn complete_dot(acc: &mut Completions, ctx: &CompletionContext) {
     };
 
     if !ctx.is_call {
-        complete_fields(acc, ctx, receiver_ty.clone());
+        complete_fields(acc, ctx, &receiver_ty);
     }
-    complete_methods(acc, ctx, receiver_ty.clone());
+    complete_methods(acc, ctx, &receiver_ty);
 
     // Suggest .await syntax for types that implement Future trait
-    if ctx.analyzer.impls_future(ctx.db, receiver_ty) {
+    if ctx.analyzer.impls_future(ctx.db, receiver_ty.into_ty()) {
         CompletionItem::new(CompletionKind::Keyword, ctx.source_range(), "await")
             .detail("expr.await")
             .insert_text("await")
@@ -35,28 +35,18 @@ pub(super) fn complete_dot(acc: &mut Completions, ctx: &CompletionContext) {
     }
 }
 
-fn complete_fields(acc: &mut Completions, ctx: &CompletionContext, receiver: Ty) {
-    for receiver in ctx.analyzer.autoderef(ctx.db, receiver) {
-        if let Ty::Apply(a_ty) = receiver {
-            match a_ty.ctor {
-                TypeCtor::Adt(Adt::Struct(s)) => {
-                    for field in s.fields(ctx.db) {
-                        acc.add_field(ctx, field, &a_ty.parameters);
-                    }
-                }
-                // FIXME unions
-                TypeCtor::Tuple { .. } => {
-                    for (i, ty) in a_ty.parameters.iter().enumerate() {
-                        acc.add_tuple_field(ctx, i, ty);
-                    }
-                }
-                _ => {}
-            }
-        };
+fn complete_fields(acc: &mut Completions, ctx: &CompletionContext, receiver: &Type) {
+    for receiver in receiver.autoderef(ctx.db) {
+        for (field, ty) in receiver.fields(ctx.db) {
+            acc.add_field(ctx, field, &ty);
+        }
+        for (i, ty) in receiver.tuple_fields(ctx.db).into_iter().enumerate() {
+            acc.add_tuple_field(ctx, i, &ty);
+        }
     }
 }
 
-fn complete_methods(acc: &mut Completions, ctx: &CompletionContext, receiver: Ty) {
+fn complete_methods(acc: &mut Completions, ctx: &CompletionContext, receiver: &Type) {
     let mut seen_methods = FxHashSet::default();
     ctx.analyzer.iterate_method_candidates(ctx.db, receiver, None, |_ty, func| {
         if func.has_self_param(ctx.db) && seen_methods.insert(func.name(ctx.db)) {
diff --git a/crates/ra_ide_api/src/completion/complete_postfix.rs b/crates/ra_ide_api/src/completion/complete_postfix.rs
index 17b75cf7e..646a30c76 100644
--- a/crates/ra_ide_api/src/completion/complete_postfix.rs
+++ b/crates/ra_ide_api/src/completion/complete_postfix.rs
@@ -1,6 +1,5 @@
 //! FIXME: write short doc here
 
-use hir::{Ty, TypeCtor};
 use ra_syntax::{ast::AstNode, TextRange, TextUnit};
 use ra_text_edit::TextEdit;
 
@@ -30,9 +29,12 @@ pub(super) fn complete_postfix(acc: &mut Completions, ctx: &CompletionContext) {
         dot_receiver.syntax().text().to_string()
     };
 
-    let receiver_ty = ctx.analyzer.type_of(ctx.db, &dot_receiver);
+    let receiver_ty = match ctx.analyzer.type_of(ctx.db, &dot_receiver) {
+        Some(it) => it,
+        None => return,
+    };
 
-    if is_bool_or_unknown(receiver_ty) {
+    if receiver_ty.is_bool() || receiver_ty.is_unknown() {
         postfix_snippet(ctx, "if", "if expr {}", &format!("if {} {{$0}}", receiver_text))
             .add_to(acc);
         postfix_snippet(
@@ -75,14 +77,6 @@ fn postfix_snippet(ctx: &CompletionContext, label: &str, detail: &str, snippet:
         .snippet_edit(edit)
 }
 
-fn is_bool_or_unknown(ty: Option<Ty>) -> bool {
-    match &ty {
-        Some(Ty::Apply(app)) if app.ctor == TypeCtor::Bool => true,
-        Some(Ty::Unknown) | None => true,
-        Some(_) => false,
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use insta::assert_debug_snapshot;
diff --git a/crates/ra_ide_api/src/completion/complete_record_literal.rs b/crates/ra_ide_api/src/completion/complete_record_literal.rs
index 45a4a9738..577c394d2 100644
--- a/crates/ra_ide_api/src/completion/complete_record_literal.rs
+++ b/crates/ra_ide_api/src/completion/complete_record_literal.rs
@@ -1,7 +1,5 @@
 //! FIXME: write short doc here
 
-use hir::Substs;
-
 use crate::completion::{CompletionContext, Completions};
 
 /// Complete fields in fields literals.
@@ -15,10 +13,9 @@ pub(super) fn complete_record_literal(acc: &mut Completions, ctx: &CompletionCon
         Some(it) => it,
         _ => return,
     };
-    let substs = &ty.substs().unwrap_or_else(Substs::empty);
 
-    for field in variant.fields(ctx.db) {
-        acc.add_field(ctx, field, substs);
+    for (field, field_ty) in ty.variant_fields(ctx.db, variant) {
+        acc.add_field(ctx, field, &field_ty);
     }
 }
 
diff --git a/crates/ra_ide_api/src/completion/complete_record_pattern.rs b/crates/ra_ide_api/src/completion/complete_record_pattern.rs
index aa0fd6d24..a56c7e3a1 100644
--- a/crates/ra_ide_api/src/completion/complete_record_pattern.rs
+++ b/crates/ra_ide_api/src/completion/complete_record_pattern.rs
@@ -1,7 +1,5 @@
 //! FIXME: write short doc here
 
-use hir::Substs;
-
 use crate::completion::{CompletionContext, Completions};
 
 pub(super) fn complete_record_pattern(acc: &mut Completions, ctx: &CompletionContext) {
@@ -14,10 +12,9 @@ pub(super) fn complete_record_pattern(acc: &mut Completions, ctx: &CompletionCon
         Some(it) => it,
         _ => return,
     };
-    let substs = &ty.substs().unwrap_or_else(Substs::empty);
 
-    for field in variant.fields(ctx.db) {
-        acc.add_field(ctx, field, substs);
+    for (field, field_ty) in ty.variant_fields(ctx.db, variant) {
+        acc.add_field(ctx, field, &field_ty);
     }
 }
 
diff --git a/crates/ra_ide_api/src/completion/presentation.rs b/crates/ra_ide_api/src/completion/presentation.rs
index 85b053a6e..5f056730a 100644
--- a/crates/ra_ide_api/src/completion/presentation.rs
+++ b/crates/ra_ide_api/src/completion/presentation.rs
@@ -1,12 +1,12 @@
 //! This modules takes care of rendering various definitions as completion items.
 
-use hir::{db::HirDatabase, Docs, HasAttrs, HasSource, HirDisplay, ScopeDef, Ty, TypeWalk};
+use hir::{db::HirDatabase, Docs, HasAttrs, HasSource, HirDisplay, ScopeDef, Type};
 use join_to_string::join;
 use ra_syntax::ast::NameOwner;
 use test_utils::tested_by;
 
 use crate::completion::{
-    db, CompletionContext, CompletionItem, CompletionItemKind, CompletionKind, Completions,
+    CompletionContext, CompletionItem, CompletionItemKind, CompletionKind, Completions,
 };
 
 use crate::display::{const_label, function_label, macro_label, type_label};
@@ -16,7 +16,7 @@ impl Completions {
         &mut self,
         ctx: &CompletionContext,
         field: hir::StructField,
-        substs: &hir::Substs,
+        ty: &Type,
     ) {
         let is_deprecated = is_deprecated(field, ctx.db);
         CompletionItem::new(
@@ -25,13 +25,13 @@ impl Completions {
             field.name(ctx.db).to_string(),
         )
         .kind(CompletionItemKind::Field)
-        .detail(field.ty(ctx.db).subst(substs).display(ctx.db).to_string())
+        .detail(ty.display(ctx.db).to_string())
         .set_documentation(field.docs(ctx.db))
         .set_deprecated(is_deprecated)
         .add_to(self);
     }
 
-    pub(crate) fn add_tuple_field(&mut self, ctx: &CompletionContext, field: usize, ty: &hir::Ty) {
+    pub(crate) fn add_tuple_field(&mut self, ctx: &CompletionContext, field: usize, ty: &Type) {
         CompletionItem::new(CompletionKind::Reference, ctx.source_range(), field.to_string())
             .kind(CompletionItemKind::Field)
             .detail(ty.display(ctx.db).to_string())
@@ -98,7 +98,7 @@ impl Completions {
             CompletionItem::new(completion_kind, ctx.source_range(), local_name.clone());
         if let ScopeDef::Local(local) = resolution {
             let ty = local.ty(ctx.db);
-            if ty != Ty::Unknown {
+            if !ty.is_unknown() {
                 completion_item = completion_item.detail(ty.display(ctx.db).to_string());
             }
         };
@@ -108,19 +108,17 @@ impl Completions {
             && !ctx.has_type_args
             && ctx.db.feature_flags.get("completion.insertion.add-call-parenthesis")
         {
-            let generic_def: Option<hir::GenericDef> = match resolution {
-                ScopeDef::ModuleDef(Adt(it)) => Some((*it).into()),
-                ScopeDef::ModuleDef(TypeAlias(it)) => Some((*it).into()),
-                _ => None,
+            let has_non_default_type_params = match resolution {
+                ScopeDef::ModuleDef(Adt(it)) => it.has_non_default_type_params(ctx.db),
+                ScopeDef::ModuleDef(TypeAlias(it)) => it.has_non_default_type_params(ctx.db),
+                _ => false,
             };
-            if let Some(def) = generic_def {
-                if has_non_default_type_params(def, ctx.db) {
-                    tested_by!(inserts_angle_brackets_for_generics);
-                    completion_item = completion_item
-                        .lookup_by(local_name.clone())
-                        .label(format!("{}<…>", local_name))
-                        .insert_snippet(format!("{}<$0>", local_name));
-                }
+            if has_non_default_type_params {
+                tested_by!(inserts_angle_brackets_for_generics);
+                completion_item = completion_item
+                    .lookup_by(local_name.clone())
+                    .label(format!("{}<…>", local_name))
+                    .insert_snippet(format!("{}<$0>", local_name));
             }
         }
 
@@ -291,11 +289,6 @@ fn is_deprecated(node: impl HasAttrs, db: &impl HirDatabase) -> bool {
     node.attrs(db).by_key("deprecated").exists()
 }
 
-fn has_non_default_type_params(def: hir::GenericDef, db: &db::RootDatabase) -> bool {
-    let subst = db.generic_defaults(def.into());
-    subst.iter().any(|ty| ty == &Ty::Unknown)
-}
-
 #[cfg(test)]
 mod tests {
     use insta::assert_debug_snapshot;