anchor.diff:      new OptionHandler('-[chv?]+', handleShortOptions),
       new OptionHandler('--throw-on-error', (_) => throwOnError = true),
       new OptionHandler('--suppress-warnings', (_) => showWarnings = false),
  -    new OptionHandler('--output-type=dart|--output-type=js', passThrough),
  +    new OptionHandler('--output-type=dart|--output-type=js', setOutputType),
       new OptionHandler('--verbose', (_) => verbose = true),
       new OptionHandler('--library-root=.+', setLibraryRoot),
       new OptionHandler('--out=.+|-o.+', setOutput),
  
positive.code:   bool explicitOut = false;
    bool wantHelp = false;
    bool enableColors = false;
  
    passThrough(String argument) => options.add(argument);
  
  
negative.code:       sourceMapOut.path.substring(sourceMapOut.path.lastIndexOf('/') + 1);
    code = '$code\n//@ sourceMappingURL=${sourceMapFileName}';
    writeString(out, code);
    int bytesWritten = code.length;
    info('compiled $dartBytesRead bytes Dart -> $bytesWritten bytes '
         '$outputLanguage in ${relativize(cwd, out, isWindows)}');
    if (!explicitOut) {
      String input = uriPathToNative(arguments[0]);
      String output = relativize(cwd, out, isWindows);
      print('Dart file $input compiled to $outputLanguage: $output');
    }
  }
  
  