precedence should not warn for unary minus before odd function #4892
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C-enhancement
Category: Enhancement of lints, like adding more cases or adding help messages
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flip1995
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Basically only a whitelist of functions has to be added. |
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Hi! Can I work on this issue ? (first issue/contribution). Thanks. |
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Sure! To get started with Clippy development you can read up in https://github.com/rust-lang/rust-clippy/blob/master/doc/adding_lints.md. If you have any questions, just ask here or open a WIP PR. |
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Apr 17, 2020
Fixes issue #4892. First contribution here 😊 ! Do not hesitate to correct me. This PR is related to issue #4892 . # Summary ```rust -literal.method_call(args) ``` The main idea is to not trigger `clippy:precedence` when the method call is an odd function. # Example ```rust // should trigger lint let _ = -1.0_f64.abs() //precedence of method call abs() and neg ('-') is ambiguous // should not trigger lint let _ = -1.0_f64.sin() // sin is an odd function => -sin(x) = sin(-x) ``` # Theory Rust allows following literals: - char - string - integers - floats - byte - bool Only integers/floats implements the relevant `std::ops::Neg`. Following odd functions are implemented on i[8-128] and/or f[32-64]: - `asin` - `asinh` - `atan` - `atanh` - `cbrt` - `fract` - `round` - `signum` - `sin` - `sinh` - `tan` - `tanh ` - `to_degrees` - `to_radians` # Implementation As suggested by `flip1995` in [comment](#4892 (comment)), this PR add a whitelist of odd functions and compare method call to the the whitelist before triggering lint.
bors
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Apr 17, 2020
Fixes issue #4892. First contribution here 😊 ! Do not hesitate to correct me. This PR is related to issue #4892 . # Summary ```rust -literal.method_call(args) ``` The main idea is to not trigger `clippy::precedence` when the method call is an odd function. # Example ```rust // should trigger lint let _ = -1.0_f64.abs() //precedence of method call abs() and neg ('-') is ambiguous // should not trigger lint let _ = -1.0_f64.sin() // sin is an odd function => -sin(x) = sin(-x) ``` # Theory Rust allows following literals: - char - string - integers - floats - byte - bool Only integers/floats implements the relevant `std::ops::Neg`. Following odd functions are implemented on i[8-128] and/or f[32-64]: - `asin` - `asinh` - `atan` - `atanh` - `cbrt` - `fract` - `round` - `signum` - `sin` - `sinh` - `tan` - `tanh ` - `to_degrees` - `to_radians` # Implementation As suggested by `flip1995` in [comment](#4892 (comment)), this PR add a whitelist of odd functions and compare method call to the the whitelist before triggering lint. changelog: Don't trigger [`clippy::precedence`] on odd functions.
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Fix was merged. Is it possible to close this issue pls ? |
flip1995
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May 5, 2020
Changes: ```` Polished lint and tests Added final lint and tests Added basic lint and tests fix redundant_pattern_matching lint add lint futures_not_send Integrate more idiomatic rust changes. Fix issue rust-lang#4892. cargo dev fmt Cleanup: Rename 'db' variable to 'diag' question_mark: don't add `as_ref()` for a call expression unit_arg suggestion may be incorrect readme: update to cargo clippy --fix command CI: performing system upgrade fixes broken apt deps on ubuntu 32bit Do not lint in macros for match lints [fix] Minor typo in GH Actions 'clippy_dev' Reenable rustfmt integration test Add test to map_flatten with an Option Lint map_flatten if caller is an Option Apply suggestions from code review manually fixing formatting at this point lol fmt rename field revert the damn fmt changes add some tests split it up for testing but the merge broke tests dogfood tasted bad fix rustfmt issue boycott manish check for unstable options Start work on clippy-fix as subcommand ````
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The
clippy:precedencelist currently warns on every instance of the form-literal.method(), as precedence looks ambiguous. However, for an odd function, i.e. a functionf(x)wheref(-x)=-f(x), the precedence doesn't matter. Many functions have this property, such assin(),atan(),cbrt(),to_radians()(andround()i think).The text was updated successfully, but these errors were encountered: