anchor.diff:  
     /// The printer used for negative or positive numbers.
     final Printer sign;
  +
  +  /// Internal integer printer.
  +  final Printer _integerPrinter;
  +
  +  /// Internal fraction printer.
  +  final Printer _fractionPrinter;
   
     FixedNumberPrinter({
       this.accuracy,
  
positive.code: 
    String _convertIntegerDigits(Iterable<int> digits) {
      final result = _formatDigits(digits, characters);
      return separator == null ? result : _separateRight(result, separator);
    }
  
    String _convertFloat(num value) {
  
negative.code:     this.delimiter = delimiterString,
      this.infinity = infinityString,
      this.nan = nanString,
      this.padding = 0,
      this.precision = 0,
      this.separator,
      this.sign = omitPositiveSign,
    })  : _integerPrinter = Printer.standard()
              .mapIf(padding > 0,
                  (printer) => printer.padRight(padding, characters[0]))
              .mapIf(separator != null,
                  (printer) => printer.separateRight(3, 0, separator)),
          _fractionPrinter = Printer.standard()
              .mapIf(precision > 0,
                  (printer) => printer.padLeft(precision, characters[0]))
              .mapIf(separator != null,
                  (printer) => printer.separateLeft(3, 0, separator));
  
    @override
    String call(Object object) => _prependSign(
  