Don't flag intentionally empty generators unreachable #15722
Conversation
This comment has been minimized.
This comment has been minimized.
mypy/checker.py
Outdated
| @@ -1063,6 +1064,20 @@ def enter_attribute_inference_context(self) -> Iterator[None]: | |||
| yield None | |||
| self.inferred_attribute_types = old_types | |||
|
|
|||
| def _is_empty_generator(self, func: FuncItem) -> bool: | |||
There was a problem hiding this comment.
| def _is_empty_generator(self, func: FuncItem) -> bool: | |
| @staticmethod | |
| def _is_empty_generator(func: FuncItem) -> bool: |
Or even better: move the function into the global scope?
mypy/checker.py
Outdated
| @@ -1240,7 +1255,7 @@ def check_func_def( | |||
| # have no good way of doing this. | |||
| # | |||
| # TODO: Find a way of working around this limitation | |||
| if len(expanded) >= 2: | |||
| if len(expanded) >= 2 or self._is_empty_generator(item): | |||
There was a problem hiding this comment.
Maybe update the multiline comment immediately above this line? We're not just suppressing reachability warnings for TypeVars with value restrictions anymore
There was a problem hiding this comment.
Yeah, I didn't want to muddy the blame for that comment 🤣
ikonst
force-pushed
the
07-19-intentionally_empty_generator_marked_as_unreachable
branch
from
e31efd3
to
5e33f47
Compare
mypy/checker.py
Outdated
| return ( | ||
| len(body := func.body.body) == 2 |
There was a problem hiding this comment.
Nit: I think the first walrus here is slightly gratuitous
| return ( | |
| len(body := func.body.body) == 2 | |
| body = func.body.body | |
| return ( | |
| len(body) == 2 |
mypy/checker.py
Outdated
| # We suppress reachability warnings for empty generators (return; yield), since there's | ||
| # no way to promote a function into a generator except by adding an "unreachable" yield. |
There was a problem hiding this comment.
| # We suppress reachability warnings for empty generators (return; yield), since there's | |
| # no way to promote a function into a generator except by adding an "unreachable" yield. | |
| # We also suppress reachability warnings for empty generator functions | |
| # (return; yield), since the most idiomatic way to promote a function into a | |
| # generator function is often to add an "unreachable" yield. |
There was a problem hiding this comment.
I had "also" at first, but I wanted to be able to remove the first comment w/o touching the second.
There was a problem hiding this comment.
Meh, I think I'd personally prioritise a readable comment over a tiny bit more churn in git blame :p
There was a problem hiding this comment.
Ahh, easy. I've just made the "TODO remove me" part second. :P
This comment has been minimized.
This comment has been minimized.
This comment has been minimized.
This comment has been minimized.
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
This comment has been minimized.
This comment has been minimized.
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
This comment has been minimized.
This comment has been minimized.
|
@AlexWaygood I removed the comment in a090d56 since now this field appears to have a long-term legitimate use. |
This comment has been minimized.
This comment has been minimized.
This comment has been minimized.
This comment has been minimized.
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
|
Diff from mypy_primer, showing the effect of this PR on open source code: graphql-core (https://github.com/graphql-python/graphql-core): typechecking got 1.05x slower (366.9s -> 386.6s)
(Performance measurements are based on a single noisy sample)
|
ikonst
deleted the
07-19-intentionally_empty_generator_marked_as_unreachable
branch
Fixes #15345.