[Python-Dev] Re: More int/long integration issues

Guido van Rossum guido@python.org
Thu, 13 Mar 2003 14:03:27 -0500

> Guido writes:
> > IMO, xrange() must die.
> >
> > As a compromise to practicality, it should lose functionality, not
> > gain any.

[Michael Chermside]
> Glad to hear it. I always found range() vs xrange() a wart.

It is, and it is one that I hate.

> But if you had it do do over, how would you do it?

I'd make range() an iterator.  To get a concrete list that you can
modify, you'd have to write list(range(N)).  But that can't be done 
without breaking backwards compatibility, so I won't.

[David Abrahams]
> OK, range() becomes lazy, then?  Or is there another plan?

The bytecode compiler should be clever enough to see that you're

  for i in range(...): ...

and that there's no definition of range other than the built-in one
(this requires a subtle change of language rules); it can then
substitute an internal equivalent to xrange().

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