[IronPython] lambda form

[Jim Hugunin]

Timothy Fitz wrote:
> On 5/8/05, Luis M. Gonzalez <luismg at gmx.net> wrote:
> > Regarding lambda, map and reduce, Guido Van Rossum has said several
> times
> > that these built-ins are amongst its "Python regrets".
> >
> > This is what he said in a recent interview:
> >
> > - If you could change some things that have been done in the
> >   langage, what would it be ?
> >
> > Drop lambda, filter, map and reduce. Make range() behave like
xrange().
> Make
> > keys() and many other methods and built-ins return iterators rather
than
> > lists.
> 
> With respect to IronPython, lambda, filter, map and reduce need to be
> implemented, for the same reasons lambda won't go away until python
> 3.0 if it ever does.

Of course IronPython implements these today and will continue to do so -
at least until we get to start targeting Python 3.0.  The main issue is
timing.  List comprehensions were implemented from the beginning, but
we're still getting around to nested scopes.  I think this is the right
priority order.

This doesn't mean that I'll stop encouraging people from using list
comprehensions instead of filter and map.  The one tangible impact of
this preference is that I'm unlikely to work on very heavy duty
optimizations to improve the performance of map/filter anytime in the
near future.

-Jim