Adds facilities for extracting Intl.message calls and generating code from translations

pkg/intl/lib/src/intl_helpers.dart

 // Copyright (c) 2012, 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.
 
 /**
  * A library for general helper code associated with the intl library
  * rather than confined to specific parts of it.
  */
 
 library intl_helpers;
 import '../date_symbols.dart';
 
 import 'dart:async';
 
 /**
  * This is used as a marker for a locale data map that hasn't been initialized,
  * and will throw an exception on any usage that isn't the fallback
  * patterns/symbols provided.
  */
 class UninitializedLocaleData<F> {
   final String message;
   final F fallbackData;
   const UninitializedLocaleData(this.message, this.fallbackData);
 
   operator [](String key) =>
       (key == 'en_US') ? fallbackData : _throwException();
+
+  String lookupMessage(String message_str, [final String desc='',
+      final Map examples=const {}, String locale,
+      String name, List<String> args]) => _throwException();
+
   List get keys => _throwException();
+
   bool containsKey(String key) => (key == 'en_US') ? true : _throwException();
 
   _throwException() {
     throw new LocaleDataException("Locale data has not been initialized"
         ", call $message.");
   }
 }
 
 class LocaleDataException implements Exception {
   final String message;
@@ skipping 19 matching lines @@
 /**
  * Initialize the message lookup mechanism. This is for internal use only.
  * User applications should import `message_lookup_local.dart` and call
  * `initializeMessages`
  */
 void initializeInternalMessageLookup(Function lookupFunction) {
   if (messageLookup is UninitializedLocaleData) {
     messageLookup = lookupFunction();
   }
 }