On Tue, Jan 13, 2009 at 6:11 AM, Kevin Sopp <baraclese@googlemail.com> wrote:
The interpretation of OR that you describe is consistent with libtommath (of course) but not with other arbitrary-precision-integer packages that I have tried. When I try either 13 OR -1 or (BIG(1) << 200) | -1, I get -1 from all of the following:
gmp java.math.BigInteger Python's built-in long type Ruby's built-in Bignum type
Likewise, all of these give me -14 for (BIG(13) ^ -1), while libtommath and mp_int give -12.
Are you trying to say that you prefer the behavior of the other libraries?
Yes, I think the common behavior is the most natural expectation, since it makes the behavior of mp_ints consistent with that of native types, at least on platforms that use two's-complement for negative numbers. I understand that two's-complement is not required by the language standard, but as best I know it's used practically everywhere. -- Nathan