[pypy-dev] Re: [pypy-svn] r20092 - pypy/dist/pypy/rpython

Christian Tismer tismer at stackless.com
Mon Nov 21 11:04:01 CET 2005

Laura Creighton wrote:

> Correct me if I am wrong, but if we allow float keys, then we make
> code that is not portable between machines that have different
> float representations?

CPython does allow float keys and doesn't have portability
problems. The only concern here is compatability with equally
values integer keys. But that does not apply to RPython, since
we there dfon't allow mixing types at all.

> Also, given that your new American friends are dealing with money,
> what is wrong with using the decimal type as keys for them, or 
> possibly better still Facundo's money module?

I needed something that is supported by RPython and that is very
fast. I'm not aware of a C implementation of the money type,
yet, but maybe I'm missing something.
64 bit long would be perfect, because they use it at a fixed decimal
scale and convert into float only for display purposes.
So float is ATM a surrogate which is ok, because 53 bits fill the
needed range, too.

And my primary goal is to show them what PyPy can do, and to
convince them that it makes sense to invest into this.

Btw. it is not the Salomon Bros/group but an individual, with his
roots in Hungary.

all the best - chris
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