Function findHelper

string.go:20–41

(l *State, isFind bool)

}

func findHelper(l *State, isFind bool) int {
	s, p := CheckString(l, 1), CheckString(l, 2)
	init := relativePosition(OptInteger(l, 3, 1), len(s))
	if init < 1 {
		init = 1
	} else if init > len(s)+1 {
		l.PushNil()
		return 1
	}
	isPlain := l.TypeOf(4) == TypeNone || l.ToBoolean(4)
	if isFind && (isPlain || !strings.ContainsAny(p, "^$*+?.([%-")) {
		if start := strings.Index(s[init-1:], p); start >= 0 {
			l.PushInteger(start + init)
			l.PushInteger(start + init + len(p) - 1)
			return 2
		}
	} else {
		l.assert(false) // TODO implement pattern matching
	}
	l.PushNil()
	return 1
}

func scanFormat(l *State, fs string) string {
	i := 0