throw exception to stop visiting

pkg/analysis_server/lib/src/services/completion/local_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.local;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/protocol.dart' as protocol show Element,
     ElementKind;
@@ skipping 16 matching lines @@
     OpType optype = request.optype;
     if (optype.includeTopLevelSuggestions) {
       _LocalVisitor localVisitor = new _LocalVisitor(
           request,
           request.offset,
           optype.includeOnlyTypeNameSuggestions,
           !optype.includeVoidReturnSuggestions);
 
       // Collect suggestions from the specific child [AstNode] that contains
       // the completion offset and all of its parents recursively.
-      request.node.accept(localVisitor);
+      localVisitor.visit(request.node);
     }
     if (optype.includeStatementLabelSuggestions ||
         optype.includeCaseLabelSuggestions) {
       _LabelVisitor labelVisitor = new _LabelVisitor(
           request,
           optype.includeStatementLabelSuggestions,
           optype.includeCaseLabelSuggestions);
-      request.node.accept(labelVisitor);
+      labelVisitor.visit(request.node);
     }
 
     // If the unit is not a part and does not reference any parts
     // then work is complete
     return !request.unit.directives.any(
         (Directive directive) =>
             directive is PartOfDirective || directive is PartDirective);
   }
 
   @override
@@ skipping 76 matching lines @@
     // ignored
   }
 
   @override
   void declaredTopLevelVar(VariableDeclarationList varList,
       VariableDeclaration varDecl) {
     // ignored
   }
 
   @override
-  bool visitFunctionExpression(FunctionExpression node) {
+  void visitFunctionExpression(FunctionExpression node) {
     // Labels are only accessible within the local function, so stop visiting
     // once we reach a function boundary.
-    finished = true;
-    return true;
+    finished();
   }
 
   @override
-  bool visitMethodDeclaration(MethodDeclaration node) {
+  void visitMethodDeclaration(MethodDeclaration node) {
     // Labels are only accessible within the local function, so stop visiting
     // once we reach a function boundary.
-    finished = true;
-    return true;
+    finished();
   }
 
   CompletionSuggestion _addSuggestion(SimpleIdentifier id) {
     if (id != null) {
       String completion = id.name;
       if (completion != null && completion.length > 0 && completion != '_') {
         CompletionSuggestion suggestion = new CompletionSuggestion(
             CompletionSuggestionKind.IDENTIFIER,
             DART_RELEVANCE_DEFAULT,
             completion,
@@ skipping 393 matching lines @@
     if (name == null || name.length <= 0) {
       return DYNAMIC;
     }
     TypeArgumentList typeArgs = type.typeArguments;
     if (typeArgs != null) {
       //TODO (danrubel) include type arguments
     }
     return name;
   }
 }