rfc1982_serial_number.py


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#!/usr/bin/env python3

class Serial:

    def __init__(self, val):
        self._val = int(val) & (2**32)

    def __int__(self):
        return self._val

    def __add__(self, val):
        return Serial(self._val + int(val))

    def __eq__(self, other):
        return int(self) == int(other)

    def __ne__(self, other):
        return int(self) != int(other)

    def __lt__(self, other):
        return self != other and (
            (self._val < other._val and other._val - self._val < 2**31) or
            (self._val > other._val and self._val - other._val > 2**31))

    def __gt__(self, other):
        return self != other and (
            (self._val < other._val and other._val - self._val > 2**31) or
            (self._val > other._val and self._val - other._val < 2**31))

if __name__ == "__main__":
    from random import randint

    for test in range(100):
        i1 = randint(0, 2**32-1)
        i2 = randint(0, 2**32-1)

        assert i1 == i2 or \
            (i1 < i2 and not (i1 > i2)) or \
            (i1 > i2 and not (i1 < i2)) or \
            int(i1) & int(i2) == 0x80000000