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| author | bors <bors@rust-lang.org> | 2023-01-09 13:47:46 +0000 |
|---|---|---|
| committer | bors <bors@rust-lang.org> | 2023-01-09 13:47:46 +0000 |
| commit | ec968198b98c6291aac6a6aac41c1e194b14e95b (patch) | |
| tree | db052830452614e4125958923b43b0ed213f78f4 /tests/rustdoc-js-std/parser-errors.js | |
| parent | b0214d81e85c5bd82ae470f1291472a9eb8a0068 (diff) | |
| parent | b6169c2a2e5a24e9905a2614e6fe469fb37f50c9 (diff) | |
| download | rust-ec968198b98c6291aac6a6aac41c1e194b14e95b.tar.gz | |
Auto merge of #13816 - WaffleLapkin:postfix_adjustment_hints, r=Veykril
Postfix adjustment hints
# Basic Description
This PR implements "postfix" adjustment hints:
They are identical to normal adjustment hints, but are rendered _after_ the expression. E.g. `expr.*` instead of `*expr`. ~~This mirrors "postfix deref" feature that I'm planning to eventually propose to the compiler.~~
# Motivation
The advantage of being postfix is that you need to add parentheses less often:
This is because a lot of "reborrow" hints are caused by field access or method calls, both of which are postfix and have higher "precedence" than prefix `&` and `*`.
Also IMHO it just looks nicer and it's more clear what is happening (order of operations).
# Modes
However, there are some cases where postfix hints need parentheses but prefix don't (for example `&x` being turned into `(&x).*.*.&` or `&**&x`).
This PR allows users to choose which look they like more. There are 4 options (`rust-analyzer.inlayHints.expressionAdjustmentHints.mode` setting):
- `prefix` — always use prefix hints (default, what was used before that PR)
- `postfix` — always use postfix hints
- `prefer_prefix` — try to minimize number of parentheses, breaking ties in favor of prefix
- `prefer_postfix` — try to minimize number of parentheses, breaking ties in favor of postfix
Comparison of all modes:
# Edge cases
Where are some rare cases where chain hints weirdly interact with adjustment hints, for example (note `SourceAnalyzer.&`):
This is pre-existing, you can get the same effect with prefix hints (`SourceAnalyzer)`).
----
Another weird thing is this:
Here `.&` is a hint and `?` is written in the source code. It looks like `?` is part of the hint because `?.` is ligature in my font. IMO this is a bug in vscode, but still worth mentioning (I'm also too lazy to report it there...).
# Fixed bugs
I've used the "needs parens" API and this accidentally fixed a bug with parens around `as`, see the test diff:
```diff,rust
let _: *const u32 = &mut 0u32 as *mut u32;
//^^^^^^^^^^^^^^^^^^^^^<mut-ptr-to-const-ptr>
+ //^^^^^^^^^^^^^^^^^^^^^(
+ //^^^^^^^^^^^^^^^^^^^^^)
...
let _: *const u32 = &mut 0u32 as *mut u32;
//^^^^^^^^^^^^^^^^^^^^^<mut-ptr-to-const-ptr>
+ //^^^^^^^^^^^^^^^^^^^^^(
+ //^^^^^^^^^^^^^^^^^^^^^)
```
# Changelog
changelog feature Add an option to make adjustment hints (aka reborrow hints) postfix
changelog fix Fix placement of parentheses around `as` casts for adjustment hints
Diffstat (limited to 'tests/rustdoc-js-std/parser-errors.js')
0 files changed, 0 insertions, 0 deletions