code: func (self Error) Error() string {
  	filename := self.Position.Filename
  	if filename == "" {
  		filename = "(anonymous)"
  	}
  	return fmt.Sprintf("%s: Line %d:%d %s",
  		filename,
  		self.Position.Line,
  		self.Position.Column,
  		self.Message,
  	)
  }
docs: // FIXME Should this be "SyntaxError"?