iter.Push from https://github.com/golang/go/issues/72083#issuecomment-2703966786

iter.go

func Push[V any](consumer func(seq iter.Seq[V])) (yield func(V) bool, stop func()) {
	var in V

	coro := func(coroYield func(struct{}) bool) {
		seq := func(seqYield func(V) bool) {
			for seqYield(in) {
				if !coroYield(struct{}{}) {
					break
				}
			}
		}
		consumer(seq)
	}

	next, stop := iter.Pull(coro)

	yield = func(v V) bool {
		in = v
		_, more := next()
		if !more {
			stop()
		}
		return more
	}

	return yield, stop
}