Document the trouble with lambdas in the guides #2105
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| ``f: Callable[[object], object] = lambda x: x`` | ||
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| Type comments on function definitions do not actually work on lambda, nor do | ||
| normal type comments help (although you can use a type comment on an assignment |
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Might be better to not mention type comments? They're effectively deprecated, and in the context we're discussing I don't think they add anything over variable annotations.
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They are a random intrusion of esoterica here, but they are a potential answer to "where would the type annotations go?", so I think it makes sense to mention that they don't work.
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I feel many readers probably won't even know what type comments are, so discussing them is more likely to confuse than to enlighten.
| 5. If you want to annotate the type of lambdas, you can bind them and annotate them | ||
| there. | ||
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| 6. Most type checkers have a setting that will warn you if anything gets deduced as |
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Could be useful to mention what those rules are for at least some type checkers (minimally mypy and pyright), so the guide is more practically useful.
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Closes #2020