include library prefix completions given trailing local method invocation

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 46 matching lines @@
   @override
   Future<bool> computeFull(AstNode node) {
     if (node is SimpleIdentifier) {
       node = node.parent;
     }
     if (node is MethodInvocation) {
       node = (node as MethodInvocation).realTarget;
     } else if (node is PropertyAccess) {
       node = (node as PropertyAccess).realTarget;
     }
-    if (node is Identifier && node.bestElement is ClassElement) {
-      node.bestElement
-          .accept(new _PrefixedIdentifierSuggestionBuilder(request));
-      return new Future.value(true);
+    if (node is Identifier) {
+      Element elem = node.bestElement;
+      if (elem is ClassElement || elem is PrefixElement) {
+        elem.accept(new _PrefixedIdentifierSuggestionBuilder(request));
+        return new Future.value(true);
+      }
     }
     if (node is Expression) {
       InterfaceTypeSuggestionBuilder.suggestionsFor(request, node.bestType);
       return new Future.value(true);
     }
     return new Future.value(false);
   }
 }
 
 /**
@@ skipping 240 matching lines @@
           if (directive.prefix.name == element.name) {
             // Suggest elements from the imported library
             LibraryElement library = directive.uriElement;
             LibraryElementSuggestionBuilder.suggestionsFor(
                 request, CompletionSuggestionKind.INVOCATION, library);
             modified = true;
           }
         }
       }
     }
-    ;
     return new Future.value(modified);
   }
 
   @override
   Future<bool> visitPropertyAccessorElement(PropertyAccessorElement element) {
     if (element != null) {
       PropertyInducingElement elemVar = element.variable;
       if (elemVar != null) {
         InterfaceTypeSuggestionBuilder.suggestionsFor(request, elemVar.type);
       }
       return new Future.value(true);
     }
     return new Future.value(false);
   }
 
   @override
   Future<bool> visitVariableElement(VariableElement element) {
     InterfaceTypeSuggestionBuilder.suggestionsFor(request, element.type);
     return new Future.value(true);
   }
 }