Steven D'Aprano <st...@remove-this-cybersource.com.au> writes: > On Sat, 21 Aug 2010 19:09:52 -0500, John Bokma wrote: > >> this means that Python should eliminate / optimize tail >> recursion. > > There have been various suggestions to add tail recursion optimization to > the language. Two problems:
[snip] > But this is not the only sort of tail-call recursion, and a traceback > like the following is useful: > > >>>> recurse(4) > Traceback (most recent call last): > File "<stdin>", line 1, in <module> > File "<stdin>", line 5, in recurse > File "<stdin>", line 3, in f > File "<stdin>", line 5, in recurse > File "<stdin>", line 3, in f > File "<stdin>", line 5, in recurse > File "<stdin>", line 3, in f > File "<stdin>", line 4, in recurse > File "<stdin>", line 2, in g > ValueError > > > If all you saw was the last line (the call to g), debugging the exception > would be significantly harder. Yup, agreed, good example. > Me personally, I'd like to see either a (preferably) run-time setting or > compile-time switch that enables/disables this optimization. Even an > explicit decorator would be fine. And lo and behold: > > http://hircus.wordpress.com/2008/06/21/python-tail-call-optimization-done-right/ > http://groups.google.com/group/comp.lang.python/msg/9b047d1392f2b8ec > > > Add it to your bag of tricks and have fun. Thanks for the links. And yes, I will add this to my bag of tricks (aka local wiki with notes ;-) ). -- John Bokma j3b Blog: http://johnbokma.com/ Facebook: http://www.facebook.com/j.j.j.bokma Freelance Perl & Python Development: http://castleamber.com/ -- http://mail.python.org/mailman/listinfo/python-list
