This resolves a TODO in the core diagnostic module to refactor this
type. It was originally an alias of `LanguageServerId` for simplicity.
Refactoring as an enum is a necessary step towards introducing
"internal" diagnostics - diagnostics emitted by core features such as
a spell checker. Fully supporting this use-case will require further
larger changes to the diagnostic type, but the change to the provider
can be made first.
Note that `Copy` is not derived for `DiagnosticProvider` (as it was
previously because `LanguageServerId` is `Copy`). In the child commits
we will add the `identifier` used in LSP pull diagnostics which is a
string - not `Copy`.
Diagnostics are currently extended if text is inserted at their end. This is
desirable when inserting text after an identifier. For example consider:
let foo = 2;
--- unused variable
Renaming the identifier should extend the diagnostic:
let foobar = 2;
------ unused variable
This is currently implemented in helix but as a consequence adding whitespaces
or a type hint also extends the diagnostic:
let foo = 2;
-------- unused variable
let foo: Bar = 2;
-------- unused variable
In these cases the diagnostic should remain unchanged:
let foo = 2;
--- unused variable
let foo: Bar = 2;
--- unused variable
As a heuristic helix will now only extend diagnostics that end on a word char
if new chars are appended to the word (so not for punctuation/ whitespace).
The idea for this mapping was inspired for the word level tracking vscode uses
for many positions. While VSCode doesn't currently update diagnostics after
receiving publishDiagnostic it does use this system for inlay hints for example.
Similarly, the new association mechanism implemented here can be used for word
level tracking of inlay hints.
A similar mapping function is implemented for word starts. Together
these can be used to make a diagnostic stick to a word. If that word
is removed that diagnostic is automatically removed too. This is the exact
same behavior VSCode inlay hints eixibit.
Language Servers are now configured in a separate table in `languages.toml`:
```toml
[langauge-server.mylang-lsp]
command = "mylang-lsp"
args = ["--stdio"]
config = { provideFormatter = true }
[language-server.efm-lsp-prettier]
command = "efm-langserver"
[language-server.efm-lsp-prettier.config]
documentFormatting = true
languages = { typescript = [ { formatCommand ="prettier --stdin-filepath ${INPUT}", formatStdin = true } ] }
```
The language server for a language is configured like this (`typescript-language-server` is configured by default):
```toml
[[language]]
name = "typescript"
language-servers = [ { name = "efm-lsp-prettier", only-features = [ "format" ] }, "typescript-language-server" ]
```
or equivalent:
```toml
[[language]]
name = "typescript"
language-servers = [ { name = "typescript-language-server", except-features = [ "format" ] }, "efm-lsp-prettier" ]
```
Each requested LSP feature is priorized in the order of the `language-servers` array.
For example the first `goto-definition` supported language server (in this case `typescript-language-server`) will be taken for the relevant LSP request (command `goto_definition`).
If no `except-features` or `only-features` is given all features for the language server are enabled, as long as the language server supports these. If it doesn't the next language server which supports the feature is tried.
The list of supported features are:
- `format`
- `goto-definition`
- `goto-declaration`
- `goto-type-definition`
- `goto-reference`
- `goto-implementation`
- `signature-help`
- `hover`
- `document-highlight`
- `completion`
- `code-action`
- `workspace-command`
- `document-symbols`
- `workspace-symbols`
- `diagnostics`
- `rename-symbol`
- `inlay-hints`
Another side-effect/difference that comes with this PR, is that only one language server instance is started if different languages use the same language server.
* misc: missing inline, outdated link
* doc: Add new theme keys and config option to book
* fix: don't panic in Tree::try_get(view_id)
Necessary for later, where we could be receiving an LSP response
for a closed window, in which case we don't want to crash while
checking for its existence
* fix: reset idle timer on all mouse events
* refacto: Introduce Overlay::new and InlineAnnotation::new
* refacto: extract make_job_callback from Context::callback
* feat: add LSP display_inlay_hint option to config
* feat: communicate inlay hints support capabilities of helix to LSP server
* feat: Add function to request range of inlay hint from LSP
* feat: Save inlay hints in document, per view
* feat: Update inlay hints on document changes
* feat: Compute inlay hints on idle timeout
* nit: Add todo's about inlay hints for later
* fix: compute text annotations for current view in view.rs, not document.rs
* doc: Improve Document::text_annotations() description
* nit: getters don't use 'get_' in front
* fix: Drop inlay hints annotations on config refresh if necessary
* fix: padding theming for LSP inlay hints
* fix: tracking of outdated inlay hints should not be dependant on document revision (because of undos and such)
* fix: follow LSP spec and don't highlight padding as virtual text
* config: add some LSP inlay hint configs
* feat(lsp): configurable diagnostic severity
Allow severity of diagnostic messages to be configured.
E.g. allow turning of Hint level diagnostics.
Fixes: https://github.com/helix-editor/helix/issues/1007
* Use language_config() method
* Add documentation for diagnostic_severity
* Use unreachable for unknown severity level
* fix: documentation for diagnostic_severity config
