use Completions to collect completions

crates/ra_analysis/src/completion.rs

@@ -15,7 +15,8 @@ use hir::source_binder;
 
 use crate::{
     db,
-    Cancelable, FilePosition
+    Cancelable, FilePosition,
+    completion::completion_item::Completions,
 };
 
 pub use crate::completion::completion_item::{CompletionItem, InsertText};
@@ -33,15 +34,15 @@ pub(crate) fn completions(
 
     let module = ctry!(source_binder::module_from_position(db, position)?);
 
-    let mut res = Vec::new();
+    let mut acc = Completions::default();
     let mut has_completions = false;
     // First, let's try to complete a reference to some declaration.
     if let Some(name_ref) = find_node_at_offset::<ast::NameRef>(file.syntax(), position.offset) {
         has_completions = true;
-        reference_completion::completions(&mut res, db, &module, &file, name_ref)?;
+        reference_completion::completions(&mut acc, db, &module, &file, name_ref)?;
         // special case, `trait T { fn foo(i_am_a_name_ref) {} }`
         if is_node::<ast::Param>(name_ref.syntax()) {
-            param_completions(&mut res, name_ref.syntax());
+            param_completions(&mut acc, name_ref.syntax());
         }
     }
 
@@ -49,10 +50,14 @@ pub(crate) fn completions(
     if let Some(name) = find_node_at_offset::<ast::Name>(file.syntax(), position.offset) {
         if is_node::<ast::Param>(name.syntax()) {
             has_completions = true;
-            param_completions(&mut res, name.syntax());
+            param_completions(&mut acc, name.syntax());
         }
     }
-    let res = if has_completions { Some(res) } else { None };
+    let res = if has_completions {
+        Some(acc.into())
+    } else {
+        None
+    };
     Ok(res)
 }
 
@@ -60,7 +65,7 @@ pub(crate) fn completions(
 /// functions in a file have a `spam: &mut Spam` parameter, a completion with
 /// `spam: &mut Spam` insert text/label and `spam` lookup string will be
 /// suggested.
-fn param_completions(acc: &mut Vec<CompletionItem>, ctx: SyntaxNodeRef) {
+fn param_completions(acc: &mut Completions, ctx: SyntaxNodeRef) {
     let mut params = FxHashMap::default();
     for node in ctx.ancestors() {
         let _ = visitor_ctx(&mut params)

crates/ra_analysis/src/completion/completion_item.rs

@@ -53,8 +53,8 @@ pub(crate) struct Builder {
 }
 
 impl Builder {
-    pub fn add_to(self, acc: &mut Vec<CompletionItem>) {
-        acc.push(self.build())
+    pub fn add_to(self, acc: &mut Completions) {
+        acc.add(self.build())
     }
 
     pub fn build(self) -> CompletionItem {
@@ -81,7 +81,7 @@ impl Into<CompletionItem> for Builder {
 }
 
 /// Represents an in-progress set of completions being built.
-#[derive(Debug)]
+#[derive(Debug, Default)]
 pub(crate) struct Completions {
     buf: Vec<CompletionItem>,
 }
@@ -90,6 +90,13 @@ impl Completions {
     pub(crate) fn add(&mut self, item: impl Into<CompletionItem>) {
         self.buf.push(item.into())
     }
+    pub(crate) fn add_all<I>(&mut self, items: I)
+    where
+        I: IntoIterator,
+        I::Item: Into<CompletionItem>,
+    {
+        items.into_iter().for_each(|item| self.add(item.into()))
+    }
 }
 
 impl Into<Vec<CompletionItem>> for Completions {

crates/ra_analysis/src/completion/reference_completion.rs

@@ -13,12 +13,12 @@ use hir::{
 
 use crate::{
     db::RootDatabase,
-    completion::CompletionItem,
+    completion::{CompletionItem, Completions},
     Cancelable
 };
 
 pub(super) fn completions(
-    acc: &mut Vec<CompletionItem>,
+    acc: &mut Completions,
     db: &RootDatabase,
     module: &hir::Module,
     file: &SourceFileNode,
@@ -117,7 +117,7 @@ fn classify_name_ref(name_ref: ast::NameRef) -> Option<NameRefKind> {
     None
 }
 
-fn complete_fn(name_ref: ast::NameRef, scopes: &FnScopes, acc: &mut Vec<CompletionItem>) {
+fn complete_fn(name_ref: ast::NameRef, scopes: &FnScopes, acc: &mut Completions) {
     let mut shadowed = FxHashSet::default();
     scopes
         .scope_chain(name_ref.syntax())
@@ -130,7 +130,7 @@ fn complete_fn(name_ref: ast::NameRef, scopes: &FnScopes, acc: &mut Vec<Completi
 }
 
 fn complete_path(
-    acc: &mut Vec<CompletionItem>,
+    acc: &mut Completions,
     db: &RootDatabase,
     module: &hir::Module,
     mut path: Path,
@@ -154,7 +154,7 @@ fn complete_path(
     Ok(())
 }
 
-fn complete_mod_item_snippets(acc: &mut Vec<CompletionItem>) {
+fn complete_mod_item_snippets(acc: &mut Completions) {
     CompletionItem::new("Test function")
         .lookup_by("tfn")
         .snippet(
@@ -174,26 +174,26 @@ fn complete_expr_keywords(
     file: &SourceFileNode,
     fn_def: ast::FnDef,
     name_ref: ast::NameRef,
-    acc: &mut Vec<CompletionItem>,
+    acc: &mut Completions,
 ) {
-    acc.push(keyword("if", "if $0 {}"));
-    acc.push(keyword("match", "match $0 {}"));
-    acc.push(keyword("while", "while $0 {}"));
-    acc.push(keyword("loop", "loop {$0}"));
+    acc.add(keyword("if", "if $0 {}"));
+    acc.add(keyword("match", "match $0 {}"));
+    acc.add(keyword("while", "while $0 {}"));
+    acc.add(keyword("loop", "loop {$0}"));
 
     if let Some(off) = name_ref.syntax().range().start().checked_sub(2.into()) {
         if let Some(if_expr) = find_node_at_offset::<ast::IfExpr>(file.syntax(), off) {
             if if_expr.syntax().range().end() < name_ref.syntax().range().start() {
-                acc.push(keyword("else", "else {$0}"));
-                acc.push(keyword("else if", "else if $0 {}"));
+                acc.add(keyword("else", "else {$0}"));
+                acc.add(keyword("else if", "else if $0 {}"));
             }
         }
     }
     if is_in_loop_body(name_ref) {
-        acc.push(keyword("continue", "continue"));
-        acc.push(keyword("break", "break"));
+        acc.add(keyword("continue", "continue"));
+        acc.add(keyword("break", "break"));
     }
-    acc.extend(complete_return(fn_def, name_ref));
+    acc.add_all(complete_return(fn_def, name_ref));
 }
 
 fn is_in_loop_body(name_ref: ast::NameRef) -> bool {
@@ -252,7 +252,7 @@ fn keyword(kw: &str, snippet: &str) -> CompletionItem {
     CompletionItem::new(kw).snippet(snippet).build()
 }
 
-fn complete_expr_snippets(acc: &mut Vec<CompletionItem>) {
+fn complete_expr_snippets(acc: &mut Completions) {
     CompletionItem::new("pd")
         .snippet("eprintln!(\"$0 = {:?}\", $0);")
         .add_to(acc);