anchor.diff:        desc: 'Error message when input number is not an integer.',
         meaning: 'Error message when input number is not an integer.');
   }
  +
  +NumberFormat decimalNumberFormat() => NumberFormat.decimalPattern();
  +
  +/// Helper directive to provide a basic [NumberFormat] pattern for use with
  +/// number accessors.
  +///
  +/// This is not necessary for standard material-input[type=num] as it's provided
  +/// as the default.  It should only be used with material-input[type=int64].
  +@Directive(
  +  selector: '[decimalNumberFormat]',
  +  providers: [Provider(NumberFormat, useFactory: decimalNumberFormat)],
  +)
  +class DecimalNumberFormatDirective {}
  
positive.code:   String formatValue(T value) {
      if (value == null) return '';
      return _numberFormat?.format(value) ?? super.formatValue(value);
    }
  }
  
  
negative.code:   CheckIntegerValidator,
    LowerBoundValidator,
    MaterialInputComponent,
    MaterialInt64ValueAccessor,
    MaterialNumberValueAccessor,
    MaterialNumberValidator,
    PositiveNumValidator,
  