Add some user-friendly utility functions to pkg/analyzer_experimental.

pkg/intl/lib/extract_messages.dart

 // Copyright (c) 2013, 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.
 
 /**
  * This is for use in extracting messages from a Dart program
  * using the Intl.message() mechanism and writing them to a file for
  * translation. This provides only the stub of a mechanism, because it
  * doesn't define how the file should be written. It provides an
  * [IntlMessage] class that holds the extracted data and [parseString]
  * and [parseFile] methods which
  * can extract messages that conform to the expected pattern:
  *       (parameters) => Intl.message("Message $parameters", desc: ...);
  * It uses the analyzer_experimental package to do the parsing, so may
  * break if there are changes to the API that it provides.
  * An example can be found in test/message_extraction/extract_to_json.dart
  *
  * Note that this does not understand how to follow part directives, so it
  * has to explicitly be given all the files that it needs. A typical use case
  * is to run it on all .dart files in a directory.
  */
 library extract_messages;
 
-import 'package:analyzer_experimental/src/generated/ast.dart';
-import 'package:analyzer_experimental/src/generated/error.dart';
-import 'package:analyzer_experimental/src/generated/java_core.dart';
-import 'package:analyzer_experimental/src/generated/parser.dart';
-import 'package:analyzer_experimental/src/generated/scanner.dart';
-import 'package:analyzer_experimental/src/generated/source.dart';
-import 'package:analyzer_experimental/src/generated/utilities_dart.dart';
 import 'dart:io';
+
+import 'package:analyzer_experimental/analyzer.dart';
 import 'package:intl/src/intl_message.dart';
 
 /**
  * If this is true, print warnings for skipped messages. Otherwise, warnings
  * are suppressed.
  */
 bool suppressWarnings = false;
 
 /**
- * Parse the dart program represented in [sourceCode] and return a Map from
- * message names to [IntlMessage] instances. The [origin] is a string
- * describing where the source came from, and is used in error messages.
- */
-Map<String, IntlMessage> parseString(String sourceCode, [String origin]) {
-  var errorListener = new _ErrorCollector();
-  var scanner = new StringScanner(null, sourceCode, errorListener);
-  var token = scanner.tokenize();
-  var parser = new Parser(null, errorListener);
-  var unit = parser.parseCompilationUnit(token);
-  unit.lineInfo = new LineInfo(scanner.lineStarts);
-
-  var visitor = new MessageFindingVisitor(unit, origin);
-  unit.accept(visitor);
-  for (var error in errorListener.errors) {
-    print(error);
-  }
-  return visitor.messages;
-}
-
-/**
  * Parse the source of the Dart program file [file] and return a Map from
  * message names to [IntlMessage] instances.
  */
 Map<String, IntlMessage> parseFile(File file) {
-  var sourceCode = file.readAsStringSync();
-  return parseString(sourceCode, file.path);
+  var unit = parseDartFile(file.path);
+  var visitor = new MessageFindingVisitor(unit, file.path);
+  unit.accept(visitor);
+  return visitor.messages;
 }
 
 /**
- * An error handler for parsing. Error handling is currently very primitive.
- */
-class _ErrorCollector extends AnalysisErrorListener {
-  List<AnalysisError> errors;
-  _ErrorCollector() : errors = new List<AnalysisError>();
-  onError(error) => errors.add(error);
-}
-
-/**
  * This visits the program source nodes looking for Intl.message uses
  * that conform to its pattern and then finding the
  */
 class MessageFindingVisitor extends GeneralizingASTVisitor {
 
   /**
    * The root of the compilation unit, and the first node we visit. We hold
    * on to this for error reporting, as it can give us line numbers of other
    * nodes.
    */
@@ skipping 239 matching lines @@
    */
   final String message;
 
   /**
    * Creates a new exception with an optional error [message].
    */
   const IntlMessageExtractionException([this.message = ""]);
 
   String toString() => "IntlMessageExtractionException: $message";
 }