Re: [myhdl-list] intbv.wrap()

[Christopher L. <loz...@fr...>]

I guess Jan D, and I see the world differently.  On so many issues.  
This should be interesting ongoing discussion.  Oh well here goes.

Jan D said:

    Really? Python doesn't have 32 bit integers that yield an overflow
    error. If you want that, tryintbv(0)[32:].


Actually I did not even know how python implements integers.  That is 
how it should be.  So I took a look at the docs and this is what they say.

http://docs.python.org/reference/datamodel.html#objects-values-and-types

    Plain integers

        These represent numbers in the range -2147483648 through
        2147483647. (The range may be larger on machines with a larger
        natural word size, but not smaller.) When the result of an
        operation would fall outside this range, the result is normally
        returned as a long integer (in some cases, the exception
        OverflowError
        <http://docs.python.org/library/exceptions.html#exceptions.OverflowError>
        is raised instead). For the purpose of shift and mask
        operations, integers are assumed to have a binary, 2's
        complement notation using 32 or more bits, and hiding no bits
        from the user (i.e., all 4294967296 different bit patterns
        correspond to different values).


So this is all useful.  Actually I prefer returning a long integer to 
the overflow error.   I wonder when the overflow error is raised?   So, 
as a python guy, using MyHDL, this is how I would like integers to behave!
No Wrapping please!   It is not part of the python spec.     Of course 
if others want wrapping, that is fine by me.

And yes, I understand that returning a different types is not typically 
done in hardware!
> Terrible? Ada has modular types. They wrap around.
Proves my point!

Regards
Chris







-- 
Regards
Christopher Lozinski

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