On 8/9/06, Travis E. Oliphant <[EMAIL PROTECTED]> wrote: > Guido van Rossum wrote: > > Here's another issue where Neal thought it would be useful if I > > weighed in. I'm not quite sure of the current status, but perhaps the > > following would work? > > > > - Called from Python, (10**10).__index__() should return 10000000000L, > > not raise an exception or return sys.maxint. > > > > - The nb_index slot is changed to return an object; it should return a > > Python int or long without clipping (same as __index__() called from > > Python). > > I don't like this approach because nb_int and nb_long are already > available to convert an object into an int or a long, so the only value > of nb_index is to make sure that floats aren't able to be converted this > way. > > The value of nb_index is that it provides a "small-overhead" means to > quickly convert any object that allows it into a Py_ssize_t value which > is needed in many internal situations (mostly indexing related). > > Rather than assume a Python integer is the only candidate for conversion > to a Py_ssize_t value, nb_index allows other objects to be used in that > fashion. Having another level of indirection where one object is first > converted to a Python int or Python long (whichever is needed) and then > to a Py_ssize_t value seems like un-necessary waste to me and will > needlessly slow certain indexing operations down.
Not if the object is implemented in Python, since then the value is necessarily returned as an int or long object anyway. Is performance of __index__ really that important? What do you think (10**10).__index__() should return (when called from Python)? > It seems like Nick's recent patches solved the problems that were > identified. Nick, can you summarize how your patches differ from my proposal? -- --Guido van Rossum (home page: http://www.python.org/~guido/) _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
