On Thu, Oct 15, 2020 at 11:38 AM Tim Peters <tim.pet...@gmail.com> wrote: > I think this is premature. There is almost never an optimization > that's a pure win in all cases. For example, on some platforms > `timsort` will never be as fast as the old samplesort in cases with a > very large number of equal elements, and on all platforms `timsort` > consumes more memory. And it's a wash on "random" data on most > platforms. Nevertheless, it was a significant speed win for many - > possibly even most - real-life cases.
And timsort is one of my go-tos for teaching the concept of hybrid sorting algorithms, because, at its heart, it's simple enough to explain, and it manages to be so incredibly valuable in real-world code. :) > But it would leave open a different idea for an "opt-in" facility: one > that allowed to give a needle to a function and get back an object > capturing the results of preprocessing. Then a different wrapper > around the search code that accepted the already-pre-processed info. > There are, e.g., certainly cases where repeated searches for a given > 4-character needle could be sped significantly by exploiting the new > code, but where the overhead of preprocessing is too much to bear in > "random" performance testing. It would also open the door to more > aggressive (expensive) kinds of preprocessing. That's where users may > be able to make useful, informed judgments. Kinda like the way a compiled regex is used? I like this idea. So it'd be heuristics in the core language that choose a good default for most situations, and then a str method that returns a preprocessed needle. In a Python implementation that doesn't want to use two different algorithms, that preprocessor could return the string unchanged, but otherwise it's an opaque object usable only in string searches. +1, if my interpretation of your description is correct. ChrisA _______________________________________________ Python-Dev mailing list -- python-dev@python.org To unsubscribe send an email to python-dev-le...@python.org https://mail.python.org/mailman3/lists/python-dev.python.org/ Message archived at https://mail.python.org/archives/list/python-dev@python.org/message/4MOC4RQDFPFGCF2OHUAK4YACGGYMTFGS/ Code of Conduct: http://python.org/psf/codeofconduct/
