(Fix #215) better error printing in editor & extension, adds mapping for editor

lib/dwc.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.
 
 /** The entry point to the compiler. Used to implement `bin/dwc.dart`. */
 library dwc;
 
 import 'dart:io';
 import 'package:logging/logging.dart' show Level;
 import 'src/compiler.dart';
@@ skipping 54 matching lines @@
   messages = new Messages(options: options);
 
   return asyncTime('Total time spent on ${options.inputFile}', () {
     var currentDir = new Directory.current().path;
     var compiler = new Compiler(fileSystem, options, currentDir);
     var res;
     return compiler.run()
       .transform((_) => (res = new CompilerResult._(messages, compiler.output)))
       .chain((_) => symlinkPubPackages(res, options))
       .chain((_) => emitFiles(compiler.output, options.clean))
-      .transform((_) => res);
+      .transform((_) {
+        _printMessages(messages, options);

[Jennifer Messerly, 2012/12/06 04:00:08]

Messages should be printed as we emit them, not all at once at the end.

[Siggi Cherem (dart-lang), 2012/12/06 18:46:42]

I don't necessarily agree, but I think I might be missing some details. Let's
chat about it in person.

+        return res;
+      });
   }, printTime: true, useColors: options.useColors);
 }
 
 Future emitFiles(List<OutputFile> outputs, bool clean) {
   outputs.forEach((f) => writeFile(f.path, f.contents, clean));
   return fileSystem.flush();
 }
 
 void writeFile(fs.Path path, String contents, bool clean) {
   if (clean) {
     File fileOut = new File.fromPath(_convert(path));
     if (fileOut.existsSync()) {
       fileOut.deleteSync();
     }
   } else {
     _createIfNeeded(_convert(path.directoryPath));
     fileSystem.writeString(path, contents);
   }
 }
 
 void _createIfNeeded(Path outdir) {
   if (outdir.isEmpty) return;
   var outDirectory = new Directory.fromPath(outdir);
   if (!outDirectory.existsSync()) {
     _createIfNeeded(outdir.directoryPath);
     outDirectory.createSync();
   }
 }
 
+void _printMessages(Messages messages, CompilerOptions options) {
+  for (var message in messages.messages) {

[Jennifer Messerly, 2012/12/06 04:00:08]

verbose messages are always printed now?

[Siggi Cherem (dart-lang), 2012/12/06 18:46:42]

Fixed. 

+    if (options.jsonFormat) {
+      print(message.toJson());
+    } else {
+      print(message);
+    }
+  }
+}
+
 /**
  * Creates a symlink to the pub packages directory in the output location. The
  * returned future completes when the symlink was created (or immediately if it
  * already exists).
  */
 Future symlinkPubPackages(CompilerResult result, CompilerOptions options) {
   if (options.outputDir == null || result.bootstrapFile == null) {
     // We don't need to copy the packages directory if the output was generated
     // in-place where the input lives or if the compiler was called without an
     // entry-point file.
@@ skipping 60 matching lines @@
         null);
     }
     return null;
   });
 }
 
 
 // TODO(sigmund): this conversion from dart:io paths to internal paths should
 // go away when dartbug.com/5818 is fixed.
 Path _convert(fs.Path path) => new Path(path.toString());