[iter_overeager_cloned]: detect .cloned().map() and .cloned().for_each() #11319
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| if let rustc_hir::ExprKind::Closure(closure) = expr.kind | ||
| && let body@ Body {params: [p], .. } = cx.tcx.hir().body(closure.body) { | ||
| match p.pat.kind { | ||
| rustc_hir::PatKind::Binding(BindingAnnotation(_, Mutability::Not), _, _, _) => { |
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We should probably expand this to other parameters as well, by using pat.walk and checking for any Bindings. If they're all used, we could lint; though I'm not sure how to handle this, maybe only if one is used?
The reason why we can't use each_binding is that it gives us the HirId of the Pat, not the binding, so we technically can but it's not pretty
Is there any reason we should lint only Binding that I'm not aware of?
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☔ The latest upstream changes (presumably #11289) made this pull request unmergeable. Please resolve the merge conflicts. |
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r? @blyxyas |
| @@ -51,8 +59,46 @@ pub(super) fn check<'tcx>( | |||
| return; | |||
| } | |||
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| if let Op::NeedlessMove(_, expr) = op { | |||
| let rustc_hir::ExprKind::Closure(closure) = expr.kind else { return } ; | |||
| let body@ Body {params: [p], .. } = cx.tcx.hir().body(closure.body) else { return }; | |||
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I think this destructuring could mean this only lints when the body has only one param.
Is this intended? If so, some optimization could be done in that walk method.
Maybe I'm wrong, am not with an IDE at the moment to corroborate this pattern destructuring.
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map and for_each require a closure of only one param
…ach() key idea: for `f` in `.map(f)` and `.for_each(f)`: 1. `f` must be a closure with one parameter 2. don't lint if mutable paramter in clsure `f`: `|mut x| ...` 3. don't lint if parameter is moved
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@bors r+ |
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☀️ Test successful - checks-action_dev_test, checks-action_remark_test, checks-action_test |
changelog: [
iter_overeager_cloned]key idea:
for
fin.map(f)and.for_each(f):fmust be closuref:|mut x| ...