[Python-Dev] Type of range object members

[Guido van Rossum]

On 8/14/06, Alexander Belopolsky <alexander.belopolsky at gmail.com> wrote:
>
> On Aug 14, 2006, at 10:56 PM, Guido van Rossum wrote:
>
> > Because the only way to create one (in 2.5 or before) is by passing it
> > a Python int.
>
> Is that true?
>
> Python 2.4.2 (#2, Jan 13 2006, 12:00:38)
>  >>> xrange(long(2))
> xrange(2)

But a long with a value larger than sys.maxint is never accepted right?

> > But since the start and end come from a Python int, what advantage
> > would it have to use Py_ssize_t instead? We know sizeof(long) <=
> > sizeof(Py_ssize_t).
>
> They don't have to come from a python int, they can come from a
> long.    I guess range_new would have to be changed to the 'n'
> conversion code instead of 'l' to do the proper conversion.
> Similarly, rangeiter_next will need to use PyInt_FromSsize_t .

Feel free to submit a patch for Python 2.6. I expect the 2.5 release
managers to reject this on the basis of being a new feature.

> > Blame the C standards committee -- they introduced ssize_t in C99.
>
> I've checked in the Wiley's 2003 edition of "The C Standard" and it
> does not have ssize_t .  I could not find anything suggesting that it
> is in the C standard on google either.  Are you sure it is in C99?

To be honest I have no idea how/why Martin or Tim picked this name.
Perhaps it is in POSIX? I doubt they made it up; ssize_t is used all
over the standard headers in the 4-year-old Linux distro (Red Hat 7.3)
running on my ancient home desktop.

-- 
--Guido van Rossum (home page: http://www.python.org/~guido/)