2 files changed, 13 insertions, 19 deletions

diff --git a/crates/ra_ide/src/completion/complete_trait_impl.rs b/crates/ra_ide/src/completion/complete_trait_impl.rs
index a610fd6d1..cf716540f 100644
--- a/crates/ra_ide/src/completion/complete_trait_impl.rs
+++ b/crates/ra_ide/src/completion/complete_trait_impl.rs
@@ -43,7 +43,7 @@ use crate::{
     completion::{
         CompletionContext, CompletionItem, CompletionItemKind, CompletionKind, Completions,
     },
-    display::FunctionSignature,
+    display::function_declaration,
 };
 
 pub(crate) fn complete_trait_impl(acc: &mut Completions, ctx: &CompletionContext) {
@@ -125,8 +125,6 @@ fn add_function_impl(
     ctx: &CompletionContext,
     func: hir::Function,
 ) {
-    let signature = FunctionSignature::from_hir(ctx.db, func);
-
     let fn_name = func.name(ctx.db).to_string();
 
     let label = if !func.params(ctx.db).is_empty() {
@@ -146,13 +144,14 @@ fn add_function_impl(
     };
     let range = TextRange::new(fn_def_node.text_range().start(), ctx.source_range().end());
 
+    let function_decl = function_declaration(&func.source(ctx.db).value);
     match ctx.config.snippet_cap {
         Some(cap) => {
-            let snippet = format!("{} {{\n    $0\n}}", signature);
+            let snippet = format!("{} {{\n    $0\n}}", function_decl);
             builder.snippet_edit(cap, TextEdit::replace(range, snippet))
         }
         None => {
-            let header = format!("{} {{", signature);
+            let header = format!("{} {{", function_decl);
             builder.text_edit(TextEdit::replace(range, header))
         }
     }
diff --git a/crates/ra_ide/src/completion/presentation.rs b/crates/ra_ide/src/completion/presentation.rs
index 64349dcb8..c7b74e635 100644
--- a/crates/ra_ide/src/completion/presentation.rs
+++ b/crates/ra_ide/src/completion/presentation.rs
@@ -11,7 +11,7 @@ use crate::{
         completion_item::Builder, CompletionContext, CompletionItem, CompletionItemKind,
         CompletionKind, Completions,
     },
-    display::{const_label, macro_label, type_label, FunctionSignature},
+    display::{const_label, function_declaration, macro_label, type_label},
     CompletionScore, RootDatabase,
 };
 
@@ -195,7 +195,6 @@ impl Completions {
 
         let name = local_name.unwrap_or_else(|| func.name(ctx.db).to_string());
         let ast_node = func.source(ctx.db).value;
-        let function_signature = FunctionSignature::from(&ast_node);
 
         let mut builder =
             CompletionItem::new(CompletionKind::Reference, ctx.source_range(), name.clone())
@@ -206,13 +205,14 @@ impl Completions {
                 })
                 .set_documentation(func.docs(ctx.db))
                 .set_deprecated(is_deprecated(func, ctx.db))
-                .detail(function_signature.to_string());
+                .detail(function_declaration(&ast_node));
 
-        let params = function_signature
-            .parameter_names
-            .iter()
-            .skip(if function_signature.has_self_param { 1 } else { 0 })
-            .map(|name| name.trim_start_matches('_').into())
+        let params = ast_node
+            .param_list()
+            .into_iter()
+            .flat_map(|it| it.params())
+            .flat_map(|it| it.pat())
+            .map(|pat| pat.to_string().trim_start_matches('_').into())
             .collect();
 
         builder = builder.add_call_parens(ctx, name, Params::Named(params));
@@ -329,15 +329,10 @@ pub(crate) fn compute_score(
     ty: &Type,
     name: &str,
 ) -> Option<CompletionScore> {
-    // FIXME: this should not fall back to string equality.
-    let ty = &ty.display(ctx.db).to_string();
     let (active_name, active_type) = if let Some(record_field) = &ctx.record_field_syntax {
         mark::hit!(record_field_type_match);
         let (struct_field, _local) = ctx.sema.resolve_record_field(record_field)?;
-        (
-            struct_field.name(ctx.db).to_string(),
-            struct_field.signature_ty(ctx.db).display(ctx.db).to_string(),
-        )
+        (struct_field.name(ctx.db).to_string(), struct_field.signature_ty(ctx.db))
     } else if let Some(active_parameter) = &ctx.active_parameter {
         mark::hit!(active_param_type_match);
         (active_parameter.name.clone(), active_parameter.ty.clone())