anchor.diff:      packageRoot = currentDirectory.resolve(extractPath(argument));
     }
   
  -  setOutput(String argument) {
  +  setOutput(Iterator<String> arguments) {
  +    String path;
  +    if (arguments.current == '-o') {
  +      if (!arguments.moveNext()) {
  +        helpAndFail('Error: Missing file after -o option.');
  +      }
  +      path = arguments.current;
  +    } else {
  +      path = extractParameter(arguments.current);
  +    }
       explicitOut = true;
  -    out = currentDirectory.resolve(nativeToUriPath(extractParameter(argument)));
  +    out = currentDirectory.resolve(nativeToUriPath(path));
       sourceMapOut = Uri.parse('$out.map');
     }
   
  
positive.code:  */
  String BUILD_ID = null;
  
  typedef void HandleOption(String option);
  
  class OptionHandler {
    String pattern;
    HandleOption handle;
  
    OptionHandler(this.pattern, this.handle);
  }
  
  /**
  
negative.code: Compiles Dart to JavaScript.
  
  Common options:
    -o <file> Generate the output into <file>.
    -c        Insert runtime type checks and enable assertions (checked mode).
    -h        Display this message (add -v for information about all options).''');
  }
  
  void verboseHelp() {
  