add keyword suggestions

pkg/analysis_services/lib/src/completion/keyword_computer.dart

+// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library services.completion.computer.dart.keyword;
+
+import 'dart:async';
+
+import 'package:analysis_services/completion/completion_computer.dart';
+import 'package:analysis_services/completion/completion_suggestion.dart';
+import 'package:analyzer/src/generated/ast.dart';
+import 'package:analyzer/src/generated/scanner.dart';
+
+/**
+ * A computer for calculating `completion.getSuggestions` request results
+ * for the local library in which the completion is requested.
+ */
+class KeywordComputer extends CompletionComputer {
+
+  @override
+  bool computeFast(CompilationUnit unit, AstNode node,
+      List<CompletionSuggestion> suggestions) {
+    node.accept(new _KeywordVisitor(suggestions));
+    return true;
+  }
+
+  @override
+  Future<bool> computeFull(CompilationUnit unit, AstNode node,
+      List<CompletionSuggestion> suggestions) {
+    return new Future.value(false);
+  }
+}
+
+/**
+ * A vistor for generating keyword suggestions.
+ */
+class _KeywordVisitor extends GeneralizingAstVisitor {
+  final List<CompletionSuggestion> suggestions;
+
+  _KeywordVisitor(this.suggestions);
+
+  visitCompilationUnit(CompilationUnit node) {
+    _addSuggestions(
+        [
+            Keyword.ABSTRACT,
+            Keyword.CLASS,
+            Keyword.CONST,
+            Keyword.EXPORT,
+            Keyword.FINAL,
+            Keyword.IMPORT,
+            Keyword.LIBRARY,
+            Keyword.PART,
+            Keyword.TYPEDEF,
+            Keyword.VAR]);
+  }
+
+  visitClassDeclaration(ClassDeclaration node) {
+    _addSuggestions([Keyword.EXTENDS, Keyword.IMPLEMENTS, Keyword.WITH]);
+  }
+
+  void _addSuggestions(List<Keyword> keywords) {
+    keywords.forEach((Keyword keyword) {
+      String completion = keyword.syntax;
+      suggestions.add(
+          new CompletionSuggestion(
+              CompletionSuggestionKind.KEYWORD,
+              CompletionRelevance.DEFAULT,
+              completion,
+              completion.length,
+              0,
+              false,
+              false));
+    });
+  }
+
+  visitNode(AstNode node) {}
+}