Collect locals in context

Author: adamrk

crates/ide/src/completion/completion_context.rs

@@ -1,7 +1,7 @@
 //! FIXME: write short doc here
 
 use base_db::SourceDatabase;
-use hir::{Semantics, SemanticsScope, Type};
+use hir::{Local, ScopeDef, Semantics, SemanticsScope, Type};
 use ide_db::RootDatabase;
 use syntax::{
     algo::{find_covering_element, find_node_at_offset},
@@ -90,6 +90,7 @@ pub(crate) struct CompletionContext<'a> {
     pub(super) impl_as_prev_sibling: bool,
     pub(super) is_match_arm: bool,
     pub(super) has_item_list_or_source_file_parent: bool,
+    pub(super) locals: Vec<(String, Local)>,
 }
 
 impl<'a> CompletionContext<'a> {
@@ -118,6 +119,12 @@ impl<'a> CompletionContext<'a> {
             original_file.syntax().token_at_offset(position.offset).left_biased()?;
         let token = sema.descend_into_macros(original_token.clone());
         let scope = sema.scope_at_offset(&token.parent(), position.offset);
+        let mut locals = vec![];
+        scope.process_all_names(&mut |name, scope| {
+            if let ScopeDef::Local(local) = scope {
+                locals.push((name.to_string(), local));
+            }
+        });
         let mut ctx = CompletionContext {
             sema,
             scope,
@@ -165,6 +172,7 @@ impl<'a> CompletionContext<'a> {
             if_is_prev: false,
             is_match_arm: false,
             has_item_list_or_source_file_parent: false,
+            locals,
         };
 
         let mut original_file = original_file.syntax().clone();

crates/ide/src/completion/presentation.rs

@@ -192,20 +192,15 @@ impl Completions {
         local_name: Option<String>,
     ) {
         fn add_arg(arg: &str, ty: &Type, ctx: &CompletionContext) -> String {
-            let mut prefix = "";
             if let Some(derefed_ty) = ty.remove_ref() {
-                ctx.scope.process_all_names(&mut |name, scope| {
-                    if prefix != "" {
-                        return;
+                for (name, local) in ctx.locals.iter() {
+                    if name == arg && local.can_unify(derefed_ty.clone(), ctx.db) {
+                        return (if ty.is_mutable_reference() { "&mut " } else { "&" }).to_string()
+                            + &arg.to_string();
                     }
-                    if let ScopeDef::Local(local) = scope {
-                        if name.to_string() == arg && local.can_unify(derefed_ty.clone(), ctx.db) {
-                            prefix = if ty.is_mutable_reference() { "&mut " } else { "&" };
-                        }
-                    }
-                });
+                }
             }
-            prefix.to_string() + arg
+            arg.to_string()
         };
         let name = local_name.unwrap_or_else(|| func.name(ctx.db).to_string());
         let ast_node = func.source(ctx.db).value;