anchor.diff:  
   void printUsage(String argv0) {
     stdout.write('usage: $argv0 [option]... [--] (FILE|-)...\n\n'
  -               '(- indicates standard input)\n');
  +      '(- indicates standard input)\n');
   }
   
   void printTerminal(Terminal terminal) {
  
positive.code:       }
      };
    } else {
      putChar = (c) { terminal.putChar(c); };
    }
  
    for (int i = first_file; i < arguments.length; i++) {
  
negative.code:     } else {
        try {
          var cList = (new File(arguments[i])).readAsBytesSync();
          cList.forEach((c) {
            putChar(c);
          });
        } on FileSystemException catch (e) {
          stderr.write('$argv0: error opening ${arguments[i]}: ${e.message}\n');
          exitCode = 1;
  