code: func (p *Parser) parseSortField() (*SortField, error) {
  	field := &SortField{}
  
  	// Parse sort field name.
  	ident, err := p.ParseIdent()
  	if err != nil {
  		return nil, err
  	}
  	field.Name = ident
  
  	// Check for optional ASC or DESC clause. Default is ASC.
  	tok, _, _ := p.ScanIgnoreWhitespace()
  	if tok != ASC && tok != DESC {
  		p.Unscan()
  		tok = ASC
  	}
  	field.Ascending = (tok == ASC)
  
  	return field, nil
  }
docs: // parseSortField parses one field of an ORDER BY clause.