On Friday, March 18, 2022 at 2:07:45 AM UTC-7, Antoon Pardon wrote: > Op 18/03/2022 om 04:14 schreef Rathmann: > > > > So what do people think of this hack/technique? Is it > > > > A) A terrible idea? (Please be specific.) > > B) Already well-known (and I just missed it.) > > C) Potentially useful for the niche case of deeply recursive > > generators? > I would go with B' + C. It seems there is a resemblance with the trampoline > technique > in order to eliminate tail recursion. I know the people of macropy have > written a > decorating macro that would eliminate tail recursion from such decorated > functions. > Maybe if you contact them they can be interested in making a similar > decorating macro > for use with such recursive decorators. > > -- > Antoon Pardon.
Thank you Antoon. I was not aware of macropy. It certainly seems like a macro could automate the process of switching the "yield from" to yield forms. That is already pretty easy to do by hand, though. The driver itself could be packaged as a decorator using just the facilities available in regular Python implementations. **Much** more ambitious would be a macro to automate the transformation of a generator from (general) recursive to iterative form, so as to avoid the need for this technique entirely. The other challenge/question would be to see if there is a way to implement this basic approach with lower overhead. So far, the savings don't kick in until the recursion hits a depth of 12 or so (even more with CPython), and many use cases have an expected recursion depth shallower than that. -- https://mail.python.org/mailman/listinfo/python-list
