}
	switch r {
	case eof, '.', ',', '|', ':', ')', '(':
		return true
	}
	return strings.HasPrefix(l.input[l.pos:], l.rightDelim)
}

// lexChar scans a character constant. The initial quote is already
// scanned. Syntax checking is done by the parser.
func lexChar(l *lexer) stateFn {
Loop:
	for {
		switch l.next() {
		case '\\':
			if r := l.next(); r != eof && r != '\n' {
				break
			}