package funky

type Iterator[V any] interface {
	Next() Maybe[V]
}

type sliceIt[V any] struct {
	idx   int
	slice []V
}

func SliceIterator[V any](sl []V) Iterator[V] {
	return &sliceIt[V]{-1, sl}
}

func (it *sliceIt[V]) Next() Maybe[V] {
	if it.idx >= len(it.slice)-1 {
		return Nothing[V]()
	}
	it.idx++
	return Just(it.slice[it.idx])
}

func Slice[V any](it Iterator[V]) []V {
	var out []V
	for m := it.Next(); !m.IsNothing(); m = it.Next() {
		out = append(out, m.Value())
	}
	return out
}