throw exception to stop visiting

pkg/analysis_server/lib/src/services/completion/invocation_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.invocation;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/services/completion/dart_completion_manager.dart';
 import 'package:analysis_server/src/services/completion/local_declaration_visitor.dart';
@@ skipping 128 matching lines @@
   DartType typeFound;
 
   /**
    * Construct a new instance to search for a declaration
    */
   _LocalBestTypeVisitor(this.targetName, int offset) : super(offset);
 
   @override
   void declaredClass(ClassDeclaration declaration) {
     if (declaration.name.name == targetName) {
-      finished = true;
       // no type
+      finished();
     }
   }
 
   @override
   void declaredClassTypeAlias(ClassTypeAlias declaration) {
     if (declaration.name.name == targetName) {
-      finished = true;
       // no type
+      finished();
     }
   }
 
   @override
   void declaredField(FieldDeclaration fieldDecl, VariableDeclaration varDecl) {
     if (varDecl.name.name == targetName) {
-      finished = true;
       // Type provided by the element in computeFull above
+      finished();
     }
   }
 
   @override
   void declaredFunction(FunctionDeclaration declaration) {
     if (declaration.name.name == targetName) {
-      finished = true;
       TypeName typeName = declaration.returnType;
       if (typeName != null) {
         typeFound = typeName.type;
       }
+      finished();
     }
   }
 
   @override
   void declaredFunctionTypeAlias(FunctionTypeAlias declaration) {
     if (declaration.name.name == targetName) {
-      finished = true;
       TypeName typeName = declaration.returnType;
       if (typeName != null) {
         typeFound = typeName.type;
       }
+      finished();
     }
   }
 
   @override
   void declaredLabel(Label label, bool isCaseLabel) {
     if (label.label.name == targetName) {
-      finished = true;
       // no type
+      finished();
     }
   }
 
   @override
   void declaredLocalVar(SimpleIdentifier name, TypeName type) {
     if (name.name == targetName) {
-      finished = true;
       typeFound = name.bestType;
+      finished();
     }
   }
 
   @override
   void declaredMethod(MethodDeclaration declaration) {
     if (declaration.name.name == targetName) {
-      finished = true;
       TypeName typeName = declaration.returnType;
       if (typeName != null) {
         typeFound = typeName.type;
       }
+      finished();
     }
   }
 
   @override
   void declaredParam(SimpleIdentifier name, TypeName type) {
     if (name.name == targetName) {
-      finished = true;
       // Type provided by the element in computeFull above
+      finished();
     }
   }
 
   @override
   void declaredTopLevelVar(VariableDeclarationList varList,
       VariableDeclaration varDecl) {
     if (varDecl.name.name == targetName) {
-      finished = true;
       // Type provided by the element in computeFull above
+      finished();
     }
   }
 }
 
 /**
  * An [Element] visitor for determining the appropriate invocation/access
  * suggestions based upon the element for which the completion is requested.
  */
 class _PrefixedIdentifierSuggestionBuilder extends
     GeneralizingElementVisitor<Future<bool>> implements SuggestionBuilder {
@@ skipping 25 matching lines @@
         if (element is! ClassElement) {
           if (type == null || type.isDynamic) {
             //
             // Given `g. int y = 0;`, the parser interprets `g` as a prefixed
             // identifier with no type.
             // If the user is requesting completions for `g`,
             // then check for a function, getter, or similar with a type.
             //
             _LocalBestTypeVisitor visitor =
                 new _LocalBestTypeVisitor(prefix.name, request.offset);
-            prefix.accept(visitor);
-            type = visitor.typeFound;
+            if (visitor.visit(prefix)) {
+              type = visitor.typeFound;
+            }
           }
           if (type != null && !type.isDynamic) {
             InterfaceTypeSuggestionBuilder.suggestionsFor(request, type);
             return new Future.value(true);
           }
         }
         if (element != null) {
           return element.accept(this);
         }
       }
@@ skipping 54 matching lines @@
     }
     return new Future.value(false);
   }
 
   @override
   Future<bool> visitVariableElement(VariableElement element) {
     InterfaceTypeSuggestionBuilder.suggestionsFor(request, element.type);
     return new Future.value(true);
   }
 }