func (l *Lexer) accept(valid ...byte) bool {
	if bytes.IndexByte(valid, l.next()) >= 0 {
		return true
	}
	l.backup()
	return false
}
// accept consumes the next byte
// if it's from the valid set.
accept consumes the next byte
if it's from the valid set.
// accept consumes the next byte // if it ' s from the valid set .
func (l *Lexer) accept(valid ...byte) bool {
	if bytes.IndexByte(valid, l.next()) >= 0 {
		return true
	}
	l.backup()
	return false
}
func ( l * Lexer ) accept ( valid ... byte ) bool { if bytes . IndexByte ( valid , l . next ( ) ) >= 0 { return true } l . backup ( ) return false }
accept consumes the next byte
if it's from the valid set.
accept consumes the next byte if it ' s from the valid set .