"""

Providing iterator functions that are not in all version of Python we support.

Where possible, we try to use the system-native version and only fall back to

these implementations if necessary.

"""

import itertools

# Fallback for Python 2.4, Python 2.5

def product(*args, **kwds):

    """

    Taken from http://docs.python.org/library/itertools.html#itertools.product

    """

    # product('ABCD', 'xy') --> Ax Ay Bx By Cx Cy Dx Dy

    # product(range(2), repeat=3) --> 000 001 010 011 100 101 110 111

    pools = map(tuple, args) * kwds.get('repeat', 1)

    result = [[]]

    for pool in pools:

        result = [x+[y] for x in result for y in pool]

    for prod in result:

        yield tuple(prod)

if hasattr(itertools, 'product'):

    product = itertools.product

def is_iterable(x):

    "A implementation independent way of checking for iterables"

    try:

        iter(x)

    except TypeError:

        return False

    else:

        return True

def all(iterable):

    for item in iterable:

        if not item:

            return False

    return True