127: Improve folding r=matklad a=aochagavia
I was messing around with adding support for multiline comments in folding and ended up changing a bunch of other things.
First of all, I am not convinced of folding groups of successive items. For instance, I don't see why it is worthwhile to be able to fold something like the following:
```rust
use foo;
use bar;
```
Furthermore, this causes problems if you want to fold a multiline import:
```rust
use foo::{
quux
};
use bar;
```
The problem is that now there are two possible folds at the same position: we could fold the first use or we could fold the import group. IMO, the only place where folding groups makes sense is when folding comments. Therefore I have **removed folding import groups in favor of folding multiline imports**.
Regarding folding comments, I made it a bit more robust by requiring that comments can only be folded if they have the same flavor. So if you have a bunch of `//` comments followed by `//!` comments, you will get two separate fold groups instead of a single one.
Finally, I rewrote the API in such a way that it should be trivial to add new folds. You only need to:
* Create a new FoldKind
* Add it to the `fold_kind` function that converts from `SyntaxKind` to `FoldKind`
Fixes#113
Co-authored-by: Adolfo Ochagavía <github@adolfo.ochagavia.xyz>
Implements a pretty barebones function signature help mechanism in
the language server.
Users can use `Analysis::resolve_callback()` to get basic information
about a call site.
Fixes#102
116: Collapse comments upon join r=matklad a=aochagavia
Todo:
- [x] Write tests
- [x] Resolve fixmes
- [x] Implement `comment_start_length` using the parser
I left a bunch of questions as fixmes. Can someone take a look at them? Also, I would love to use the parser to calculate the length of the leading characters in a comment (`//`, `///`, `//!`, `/*`), so any hints are greatly appreciated.
Co-authored-by: Adolfo Ochagavía <aochagavia92@gmail.com>
Co-authored-by: Adolfo Ochagavía <github@adolfo.ochagavia.xyz>
93: Support leading pipe in match arms r=matklad a=DJMcNab
This adds support for match arms of the form:
```rust
<...>
| X | Y => <...>,
| X => <...>,
| 1..2 => <...>,
etc
```
# Implementation discussion
This just naïvely 'eats' a leading pipe if one is available. The equivalent line in the reference `libsyntax` is in [`parse_arm`](441519536c/src/libsyntax/parse/parser.rs (L3552)).
As noted in the comment linked above, this feature was formally introduced as a result of rust-lang/rfcs#1925. This feature is in active use in the [`rust-analyzer` codebase](c87fcb4ea5/crates/ra_syntax/src/syntax_kinds/generated.rs (L231))
I have added some tests for this feature, but maybe more would be required
EDIT: Always looking for feedback - is this PR description over-engineered?
Co-authored-by: Daniel McNab <36049421+djmcnab@users.noreply.github.com>
