code: func (p Position) String() string {
  	_prefix := ""
  	if p.File != "" {
  		_prefix = p.File + ": "
  	}
  
  	if p.Line == 0 {
  		return fmt.Sprintf("%s+%d", _prefix, p.Offset)
  	} else if p.Column == 0 {
  		return fmt.Sprintf("%s%d", _prefix, p.Line)
  	} else {
  		return fmt.Sprintf("%s%d:%d", _prefix, p.Line, p.Column)
  	}
  }
docs: // String returns a string representation of the current position.