def zip(asker, req, a, b):
if (properties.check_firmly(asker, is_empty(), a) or
properties.check_firmly(asker, is_empty(), b)):
return asker.reply(answer=empty())
zipped_first = T.pair(fields.get(asker, first(), a), fields.get(asker, first(), b))
zipped_tail = zip(fields.get(asker, tail(), a), fields.get(asker, tail(), b))
return asker.ask_tail(convert.convert(cons(zipped_first, zipped_tail), req))
def dict_cons_to_list(asker, key, value, other):
return asker.reply(answer=cons(T.pair(key, value), from_dict(other)))
