__author__ = 'aweil'

def test_xrange_27():
    from itertools import takewhile, count, islice
    sign = lambda x: x.__cmp__(0)

    def v1 (start,stop,step ):
        return takewhile(lambda x:sign(stop-x)==sign(step), (start+i*step for i in count()))

    def v2 (start,stop,step ):
        return takewhile(lambda x:stop.__cmp__(x)==sign(step), (start+i*step for i in count()))

    def v3 (start,stop,step ):
        return takewhile(lambda x:stop.__cmp__(x)==step.__cmp__(0), (start+i*step for i in count()))

    def py26(start,stop,step):
        # from file:///usr/share/doc/python2.6-doc/html/library/functions.html#xrange
        return takewhile(lambda x:x<stop, (start+i*step for i in count()))

    def py27(start,stop,step):
        # from: http://docs.python.org/library/functions.html?highlight=xrange#xrange
        return islice(count(start, step), (stop-start+step-1)//step)

    def xrangef(start,stop,step):
        return xrange(start,stop,step)
    
    all_versions = [xrangef, py26, py27, v1, v2, v3]

    start = 5
    stop = -1
    step = -1
    for func in all_versions:
        print func.func_name, list( func (start, stop, step))
    print '-----------------------'

    
    start = 5
    stop = -4
    step = -2
    for func in all_versions:
        print func.func_name, list( func (start, stop, step))
    print ' fin'


if __name__=="__main__":
    test_xrange_27()