from itertools import takewhile, starmap, islice, repeat
from operator import truth

from funcy import iterate


def chunk_iterable(iterable, chunk_size):
    return takewhile(truth, map(tuple, starmap(islice, repeat((iter(iterable), chunk_size)))))


def until_convergence(func, *args, **kwargs):
    for a, b in chunk_iterable(iterate(func, *args, **kwargs), chunk_size=2):
        if len(a) == len(b):
            return a