Function consumer

Lib/_pylong.py:706–722

(w, limit, need_hi)

# minute, because it tries millions of cases.
if 0:
    def consumer(w, limit, need_hi):
        seen = set()
        need = set()
        def inner(w):
            if w <= limit:
                return
            if w in seen:
                return
            seen.add(w)
            lo = w >> 1
            hi = w - lo
            need.add(hi if need_hi else lo)
            inner(lo)
            inner(hi)
        inner(w)
        exp = compute_powers(w, 1, limit, need_hi=need_hi)
        assert exp.keys() == need

    from itertools import chain
    for need_hi in (False, True):