[Numpy-discussion] On my Cython/NumPy project

Anne Archibald peridot.faceted@gmail....
Sat Jun 21 18:45:37 CDT 2008


2008/6/21 Robert Kern <robert.kern@gmail.com>:
> On Sat, Jun 21, 2008 at 17:08, Anne Archibald <peridot.faceted@gmail.com> wrote:
>> My suggestion is this: allow negative indices, accepting the cost in
>> tight loops. (If bounds checking is enabled, the cost will be
>> negligible anyway.) Provide a #pragma allowing the user to assert that
>> a certain piece of code uses no negative indices.
>
> Instead of a #pragma, you could rely on the type of the index. If it
> is unsigned, you can do the fast path; if it is signed, you need to
> check for and handle potential negatives.

Cute! And then it's easy to make "for i in range(n)" produce unsigned
results with no effort on the part of the user.

Anne


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