anchor.diff:              {isNum(input.LA(2))}?=> (FloatWithLeadingDot) {$type=DecimalLiteral;}
           |
           ) (
  -            UnitSpecifier {if($type == DecimalLiteral) {$type=UnitDecimalLiteral;} else {$type=UnitLiteral;}}
  +            UnitSpecifier {$type = unitType($type);}
           |
           )
       |   NonZeroDecimal (
  
positive.code: 
    public boolean isNum(int c) {
        return c>='0' && c<='9';
    }
  }
  
  
negative.code: 
  RegexpLiteral
      :  ('#/'
              ( ({!lookingAtInterpolation()}?=> ( EscapeSequenceRegexp | ~('\\'|'/')))* )
              (
                  '#{' {startRegexpInterpolation(); }
              |   '/' RegexpModifier))
      |  ('#r[' 
          ( ({!lookingAtInterpolation()}?=> (EscapeSequenceRegexp | ~('\\'|']')))* ) 
          (
              '#{' {startAltRegexpInterpolation(); }
          |   ']' RegexpModifier))
      | {isRegexpInterpolating()}?=> ('}' (({!lookingAtInterpolation()}?=> (EscapeSequenceRegexp | ~('\\'|'/')))* ) 
          (
              '#{' {startRegexpInterpolation(); }
  
          |   '/' RegexpModifier  {endRegexpInterpolation(); }))
      | {isAltRegexpInterpolating()}?=> ('}' ( ({!lookingAtInterpolation()}?=> (EscapeSequenceRegexp | ~('\\'|']')))* ) 
          (
              '#{' {startAltRegexpInterpolation(); }
          |   '/' RegexpModifier {endAltRegexpInterpolation(); }))
  