Method parseSelector

parser.go:765–813

parseSelector parses a selector that may include combinators.

()

// parseSelector parses a selector that may include combinators.
func (p *parser) parseSelector() (result Selector, err error) {
	p.skipWhitespace()
	result, err = p.parseSimpleSelectorSequence()
	if err != nil {
		return
	}

	for {
		var combinator byte
		if p.skipWhitespace() {
			combinator = ' '
		}
		if p.i >= len(p.s) {
			return
		}

		switch p.s[p.i] {
		case '+', '>', '~':
			combinator = p.s[p.i]
			p.i++
			p.skipWhitespace()
		case ',', ')':
			// These characters can't begin a selector, but they can legally occur after one.
			return
		}

		if combinator == 0 {
			return
		}

		c, err := p.parseSimpleSelectorSequence()
		if err != nil {
			return nil, err
		}

		switch combinator {
		case ' ':
			result = descendantSelector(result, c)
		case '>':
			result = childSelector(result, c)
		case '+':
			result = siblingSelector(result, c, true)
		case '~':
			result = siblingSelector(result, c, false)
		}
	}

	panic("unreachable")
}

// parseSelectorGroup parses a group of selectors, separated by commas.
func (p *parser) parseSelectorGroup() (result Selector, err error) {