This was a bit complicated. I've added a wrapper type for now that does the
LocalSyntaxPtr <-> ExprId translation; we might want to get rid of that or give
it a nicer interface.
Since we need to be able to go from def to containing impl block, as well as the
other direction, and to find all impls for a certain type, a design similar to
the one for modules, where we collect all impls for the whole crate and keep
them in an arena, seemed fitting. The ImplBlock type, which provides the public
interface, then consists only of an Arc to the arena containing all impls, and
the index into it.
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
