anchor.diff:    }
   
     static String escapePipe(String input) {
  -    var result = new StringBuffer();
  -    for (var c in input.codeUnits) {
  -      if (c == '\\' || c == '|') {
  +    StringBuffer result = new StringBuffer();
  +    for (int c in input.codeUnits) {
  +      if (c == _slashCodeUnit || c == _pipeCodeUnit) {
           result.write('\\');
         }
         result.writeCharCode(c);
  
positive.code:     }
      out.writeln();
    }
  
    void formatErrors(List<AnalysisErrorInfo> errorInfos) {
      stats.unfilteredCount += errorInfos.length;
  
  
negative.code: /// The two format options are a user consumable format and a machine consumable
  /// format.
  class ErrorFormatter {
    static final int _pipeCodeUnit = '|'.codeUnitAt(0);
    static final int _slashCodeUnit = '\\'.codeUnitAt(0);
  
    final StringSink out;
    final CommandLineOptions options;
    final AnalysisStats stats;
  
    final _SeverityProcessor processSeverity;
  
    ErrorFormatter(this.out, this.options, this.stats,
  