[Python-Dev] PEP for adding an sq_index slot so that any object, a or b, can be used in X[a:b] notation

[Brett Cannon]

On 2/9/06, Travis Oliphant <oliphant.travis at ieee.org> wrote:
>
> Guido seemed accepting to this idea about 9 months ago when I spoke to
> him.  I finally got around to writing up the PEP.   I'd really like to
> get this into Python 2.5 if possible.
>
> -Travis
>
>
>
>
> PEP:  ###
> Title:  Allowing any object to be used for slicing

Overally I am fine with the idea.  Being used as an index is different
than coercion into an int so adding this extra method seems
reasonable.

> Implementation Plan
>
>    1) Add the slots
>
>    2) Change the ISINT macro in ceval.c to accomodate objects with the
>    index slot defined.
>

Maybe the macro should also be renamed?  Not exactly testing if
something is an int anymore if it checks for __index__.

>    3) Change the _PyEval_SliceIndex function to accomodate objects
>    with the index slot defined.
>

-Brett