WIP itertool multi

multi-itertool.py

def mmp(f):
    def _m(x, prev=None):
        if prev:
            yield from prev
        yield f(x)
    return _m


def fft(f):
    def _m(x, prev=None):
        if prev:
            yield from prev
        if f(x):
            yield x
    return _m


def tef(xs, fs):
    fsi = list(enumerate(fs))
    ys = [None for _ in range(len(fs))]
    for x in xs:
        for i, f in fsi:
            y = ys[i]
            ys[i] = f(x, y)
    return ys


if __name__ == '__main__':
    maped, filtered = tef(
        range(10),
        [
            mmp(lambda x: x + 3),
            fft(lambda x: x % 2 == 0),
        ]
    )

    print(list(maped))
    print(list(filtered))