Matthias Krüger 202c70666f Rollup merge of #103478 - SpanishPear:spanishpear/issue_103366_fix, r=TaKO8Ki ... Suggest fix for misplaced generic params on fn item #103366 fixes #103366 This still has some work to go, but works for 2/3 of the initial base cases described in #1033366 simple fn: ``` error: expected identifier, found `<` --> shreys/test_1.rs:1:3 | 1 | fn<T> id(x: T) -> T { x } | ^ expected identifier | help: help: place the generic parameter list after the function name: | 1 | fn id<T>(x: T) -> T { x } | ~~~~ ``` Complicated bounds ``` error: expected identifier, found `<` --> spanishpear/test_2.rs:1:3 | 1 | fn<'a, B: 'a + std::ops::Add<Output = u32>> f(_x: B) { } | ^ expected identifier | help: help: place the generic parameter list after the function name: | 1 | fn f<'a, B: 'a + std::ops::Add<Output = u32>>(_x: B) { } | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ``` Opening a draft PR for comments on approach, particularly I have the following questions: - [x] Is it okay to be using `err.span_suggestion` over struct derives? I struggled to get the initial implementation (particularly the correct suggestion message) on struct derives, although I think given what I've learned since starting, I could attempt re-doing it with that approach. - [x] in the case where the snippet cannot be obtained from a span, is the `help` but no suggestion okay? I think yes (also, when does this case occur?) - [x] are there any red flags for the generalisation of this work for relevant item kinds (i.e. `struct`, `enum`, `trait`, and `union`). My basic testing indicates it does work for those types except the help tip is currently hardcoded to `after the function name` - which should change dependent on the item. - [x] I am planning to not show the suggestion if there is already a `<` after the item identifier, (i.e. if there are already generics, as after a function name per the original issue). Any major objections? - [x] Is the style of error okay? I wasn't sure if there was a way to make it display nicer, or if thats handled by span_suggestion These aren't blocking questions, and I will keep working on: - check if there is a `<` after the ident (and if so, not showing the suggestion) - generalize the help message - figuring out how to write/run/etc ui tests (including reading the docs for them) - logic cleanups		2023-02-14 18:02:50 +01:00
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src	Rollup merge of #103478 - SpanishPear:spanishpear/issue_103366_fix, r=TaKO8Ki	2023-02-14 18:02:50 +01:00
Cargo.toml	Use ThinVec in ast::Path.	2022-11-17 13:56:38 +11:00