On Saturday, July 18, 2015 at 9:18:32 AM UTC+5:30, Serhiy Storchaka wrote: > On 17.07.15 02:46, Chris Angelico wrote: > > Out of the lengthy thread on tail call optimization has come one broad > > theory that might be of interest, so I'm spinning it off into its own > > thread. > > > > The concept is like the Unix exec[vlpe] family of functions: replace > > the current stack frame with a new one. This can be used for explicit > > tail recursion without repeated stack frames, or for a pre-check that > > then disappears out of the stack. Like any other feature, it can be > > misused to make debugging difficult, but among consenting adults, > > hopefully it can be used sensibly. > > I think there is no chance that this proposition will be accepted by > Guido, because it makes debugging harder.
I personally thought Chris was being tongue-in-cheek with this suggestion. Taking it more seriously, here are some thoughts. Given: 1. A new keyword is a more deep change than a new optimzation flag 2. The tail-call site is (arguably!) more crucial than the tail-call So why not have a tco decorator such that @tco def foo(...): body will have tail-calls in body optimized? My guess is that someone who knows enough of python's code generator may even be able to do it in pure python; ie with no change to the language in foo.__code__.co_code, replace code of the form "... call; ret..." with "...goto..." -- https://mail.python.org/mailman/listinfo/python-list
