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| References | (5 earlier) <87383fo062.fsf@Equus.decebal.nl> <87egmzl4yr.fsf@elektro.pacujo.net> <mailman.4.1430558719.12865.python-list@python.org> <87a8xnl2r6.fsf@elektro.pacujo.net> <mi2b49$pip$1@dont-email.me> |
|---|---|
| Date | 2015-05-02 21:21 +1000 |
| Subject | Re: Python is not bad ;-) |
| From | Chris Angelico <rosuav@gmail.com> |
| Newsgroups | comp.lang.python |
| Message-ID | <mailman.9.1430565706.12865.python-list@python.org> (permalink) |
On Sat, May 2, 2015 at 9:07 PM, Christian Gollwitzer <auriocus@gmx.de> wrote:
> I need to add, I grew up with imperative programming, and as such got
> recursion as the solution to problems that are too complex for iteration,
> i.e. tree traversal and such, and exactly these are never tail-recursive.
Tree traversal can be forking-recursive:
def walk(func):
if self.left and self.left.walk(func): return 1
if func(self.payload): return 1
if self.right: return self.right.walk(func)
The left walk is non-tail-recursive, but the right walk is. This
particular style looks rather less clean with iteration:
def walk(func):
while True:
if self.left and self.left.walk(func): return 1
if func(self.payload): return 1
if not self.right: break
self = self.right
I'd call this an example of fairly natural tail recursion.
ChrisA
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Python is not bad ;-) Cecil Westerhof <Cecil@decebal.nl> - 2015-04-30 09:07 +0200
Re: Python is not bad ;-) Ben Finney <ben+python@benfinney.id.au> - 2015-04-30 19:10 +1000
Re: Python is not bad ;-) Marko Rauhamaa <marko@pacujo.net> - 2015-04-30 13:16 +0300
Re: Python is not bad ;-) Chris Angelico <rosuav@gmail.com> - 2015-04-30 20:52 +1000
Re: Python is not bad ;-) Cecil Westerhof <Cecil@decebal.nl> - 2015-04-30 13:30 +0200
Re: Python is not bad ;-) Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-05-01 17:03 +1000
Re: Python is not bad ;-) Cecil Westerhof <Cecil@decebal.nl> - 2015-05-01 09:47 +0200
Re: Python is not bad ;-) Christian Gollwitzer <auriocus@gmx.de> - 2015-05-01 19:56 +0200
Re: Python is not bad ;-) Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2015-05-02 19:44 +1200
Re: Python is not bad ;-) Cecil Westerhof <Cecil@decebal.nl> - 2015-05-02 10:26 +0200
Re: Python is not bad ;-) Marko Rauhamaa <marko@pacujo.net> - 2015-05-02 12:10 +0300
Re: Python is not bad ;-) Chris Angelico <rosuav@gmail.com> - 2015-05-02 19:25 +1000
Re: Python is not bad ;-) Marko Rauhamaa <marko@pacujo.net> - 2015-05-02 12:58 +0300
Re: Python is not bad ;-) Dave Angel <davea@davea.name> - 2015-05-02 06:22 -0400
Re: Python is not bad ;-) Chris Angelico <rosuav@gmail.com> - 2015-05-02 20:42 +1000
Re: Python is not bad ;-) Christian Gollwitzer <auriocus@gmx.de> - 2015-05-02 13:07 +0200
Re: Python is not bad ;-) Chris Angelico <rosuav@gmail.com> - 2015-05-02 21:21 +1000
Re: Python is not bad ;-) Christian Gollwitzer <auriocus@gmx.de> - 2015-05-02 13:32 +0200
Re: Python is not bad ;-) Marko Rauhamaa <marko@pacujo.net> - 2015-05-02 14:42 +0300
Re: Python is not bad ;-) Ian Kelly <ian.g.kelly@gmail.com> - 2015-05-02 09:45 -0600
Re: Python is not bad ;-) Chris Angelico <rosuav@gmail.com> - 2015-05-03 01:55 +1000
Re: Python is not bad ;-) Joonas Liik <liik.joonas@gmail.com> - 2015-05-02 16:50 +0300
Re: Python is not bad ;-) Joonas Liik <liik.joonas@gmail.com> - 2015-05-02 18:53 +0300
Re: Python is not bad ;-) Ian Kelly <ian.g.kelly@gmail.com> - 2015-05-02 11:00 -0600
Re: Python is not bad ;-) Ian Kelly <ian.g.kelly@gmail.com> - 2015-05-02 11:17 -0600
Re: Python is not bad ;-) Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-05-02 18:22 +0100
Re: Python is not bad ;-) Cecil Westerhof <Cecil@decebal.nl> - 2015-05-02 12:29 +0200
Re: Python is not bad ;-) Cecil Westerhof <Cecil@decebal.nl> - 2015-05-02 11:33 +0200
Re: Python is not bad ;-) Dave Angel <davea@davea.name> - 2015-05-02 06:35 -0400
Re: Python is not bad ;-) Cecil Westerhof <Cecil@decebal.nl> - 2015-05-02 13:12 +0200
Re: Python is not bad ;-) Ian Kelly <ian.g.kelly@gmail.com> - 2015-05-02 09:31 -0600
Re: Python is not bad ;-) Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-05-01 15:56 +1000
Re: Python is not bad ;-) Cecil Westerhof <Cecil@decebal.nl> - 2015-04-30 13:10 +0200
Re: Python is not bad ;-) Michael Torrie <torriem@gmail.com> - 2015-04-30 08:03 -0600
Re: Python is not bad ;-) Cecil Westerhof <Cecil@decebal.nl> - 2015-04-30 18:11 +0200
Re: Python is not bad ;-) Christian Gollwitzer <auriocus@gmx.de> - 2015-04-30 19:59 +0200
Re: Python is not bad ;-) Cecil Westerhof <Cecil@decebal.nl> - 2015-04-30 22:05 +0200
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