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>
118: Remove error publishing through publishDecorations r=matklad a=aochagavia
The errors are already reported by `publishDiagnostics`
Closes#109
Co-authored-by: Adolfo Ochagavía <aochagavia92@gmail.com>
98: WIP: Add resolve_local_name to resolve names in a function scope r=kjeremy a=kjeremy
First step to resolving #80
Co-authored-by: Jeremy A. Kolb <jkolb@ara.com>
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>
67: Salsa r=matklad a=matklad
The aim of this PR is to transition from rather ad-hock FileData and ModuleMap caching strategy to something resembling a general-purpose red-green engine.
Ideally, we shouldn't recompute ModuleMap at all, unless the set of mod decls or files changes.
Co-authored-by: Aleksey Kladov <aleksey.kladov@gmail.com>
69: Incremental reparsing for single tokens r=matklad a=darksv
Implement incremental reparsing for `WHITESPACE`, `COMMENT`, `DOC_COMMENT`, `IDENT`, `STRING` and `RAW_STRING`. This allows to avoid reparsing whole blocks when a change was made only within these tokens.
Co-authored-by: darksv <darek969-12@o2.pl>
This commit is an example of fixing a common parser error: infinite
loop due to error recovery.
This error typically happens when we parse a list of items and fail to
parse a specific item at the current position.
One choices is to skip a token and try to parse a list item at the
next position. This is a good, but not universal, default. When
parsing a list of arguments in a function call, you, for example,
don't want to skip over `fn`, because it's most likely that it is a
function declaration, and not a mistyped arg:
```
fn foo() {
quux(1, 2
fn bar() {
}
```
Another choice is to bail out of the loop immediately, but it isn't
perfect either: sometimes skipping over garbage helps:
```
quux(1, foo:, 92) // should skip over `:`, b/c that's part of `foo::bar`
```
In general, parser tries to balance these two cases, though we don't
have a definitive strategy yet.
However, if the parser accidentally neither skips over a token, nor
breaks out of the loop, then it becomes stuck in the loop infinitely
(there's an internal counter to self-check this situation and panic
though), and that's exactly what is demonstrated by the test.
To fix such situation, first of all, add the test case to tests/data/parser/{err,fuzz-failures}.
Then, run
```
RUST_BACKTRACE=short cargo test --package libsyntax2
````
to verify that parser indeed panics, and to get an idea what grammar
production is the culprit (look for `_list` functions!).
In this case, I see
```
10: libsyntax2::grammar::expressions::atom::match_arm_list
at crates/libsyntax2/src/grammar/expressions/atom.rs:309
```
and that's look like it might be a culprit. I verify it by adding
`eprintln!("loopy {:?}", p.current());` and indeed I see that this is
printed repeatedly.
Diagnosing this a bit shows that the problem is that
`pattern::pattern` function does not consume anything if the next
token is `let`. That is a good default to make cases like
```
let
let foo = 92;
```
where the user hasn't typed the pattern yet, to parse in a reasonable
they correctly.
For match arms, pretty much the single thing we expect is a pattern,
so, for a fix, I introduce a special variant of pattern that does not
do recovery.
As described in #61, fuzz testing some parts of this would be ~~fun~~
helpful. So, I started with the most trivial fuzzer I could think of:
Put random stuff into File::parse and see what happens.
To speed things up, I also did
cp src/**/*.rs fuzz/corpus/parser/
in the `crates/libsyntax2/` directory (running the fuzzer once will
generate the necessary directories).
