Method parseAttributeSelector

parser.go:329–415

parseAttributeSelector parses a selector that matches by attribute value.

()

// parseAttributeSelector parses a selector that matches by attribute value.
func (p *parser) parseAttributeSelector() (Selector, error) {
	if p.i >= len(p.s) {
		return nil, fmt.Errorf("expected attribute selector ([attribute]), found EOF instead")
	}
	if p.s[p.i] != '[' {
		return nil, fmt.Errorf("expected attribute selector ([attribute]), found '%c' instead", p.s[p.i])
	}

	p.i++
	p.skipWhitespace()
	key, err := p.parseIdentifier()
	if err != nil {
		return nil, err
	}

	p.skipWhitespace()
	if p.i >= len(p.s) {
		return nil, errors.New("unexpected EOF in attribute selector")
	}

	if p.s[p.i] == ']' {
		p.i++
		return attributeExistsSelector(key), nil
	}

	if p.i+2 >= len(p.s) {
		return nil, errors.New("unexpected EOF in attribute selector")
	}

	op := p.s[p.i : p.i+2]
	if op[0] == '=' {
		op = "="
	} else if op[1] != '=' {
		return nil, fmt.Errorf(`expected equality operator, found "%s" instead`, op)
	}
	p.i += len(op)

	p.skipWhitespace()
	if p.i >= len(p.s) {
		return nil, errors.New("unexpected EOF in attribute selector")
	}
	var val string
	var rx *regexp.Regexp
	if op == "#=" {
		rx, err = p.parseRegex()
	} else {
		switch p.s[p.i] {
		case '\'', '"':
			val, err = p.parseString()
		default:
			val, err = p.parseIdentifier()
		}
	}
	if err != nil {
		return nil, err
	}

	p.skipWhitespace()