[mypyc] feat: reorder gens for speed in ForZip.gen_condition
#20116
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Not all generators have an equally fast gen_condition, some are quite fast while others quite the opposite This PR orders them in what I see to be a reasonably fastest -> slowest order
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BobTheBuidler
commented
Oct 24, 2025
mypyc/irbuild/for_helpers.py
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| # this is a failsafe for ForHelper classes which might have been added after this commit but not added to this function's code | ||
| leftovers = [g for g in gens if g not in ordered + for_iterable] | ||
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| for i, gen in enumerate(ordered + leftovers + for_iterable): |
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hmmm does this break Python semantics in cases where the input is an Iterator with def __iter__(self) -> Self:?
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or a native generator*?
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I guess we could defer to the existing code in those cases. Which renders this PR a whole lot less useful, but it still leaves us with a tangible improvement in some cases.
BobTheBuidler
changed the title
ForZip.gen_condition
for more information, see https://pre-commit.ci
for more information, see https://pre-commit.ci
for more information, see https://pre-commit.ci
for more information, see https://pre-commit.ci
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Not all generators have an equally fast gen_condition, some are quite fast while others quite the opposite
This PR orders them in what I see to be a reasonably fastest -> slowest order