* Add initial support for LSP DidChangeWatchedFiles
* Move file event Handler to helix-lsp
* Simplify file event handling
* Refactor file event handling
* Block on future within LSP file event handler
* Fully qualify uses of the file_event::Handler type
* Rename ops field to options
* Revert newline removal from helix-view/Cargo.toml
* Ensure file event Handler is cleaned up when lsp client is shutdown
The LSP spec has this to say about initialize:
> Until the server has responded to the `initialize` request with an
> `InitializeResult`, the client must not send any additional requests
> or notifications to the server.
(https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#initialize)
The spec is not really explicit about how to handle this scenario.
Before a client sends the 'initialize' request we are allowed to send an
'exit' notification, but after 'initialize' we can't send any requests
(like shutdown) or notifications (like exit). So my intepretation is
that we should forcefully close the server in this state.
This matches the behavior of Neovim's built-in LSP client:
5ceb2238d3/runtime/lua/vim/lsp.lua (L1610-L1628)
* Add `helix_lsp::client::Client::supports_feature(&self, LanguageServerFeature)`
* Extend `doc.language_servers_with_feature` to use this method as filter as well
* Add macro `language_server_with_feature!` to reduce boilerplate for non-mergeable language server requests (like goto-definition)
* Refactored most of the `find_map` code to use the either the macro or filter directly via `doc.language_servers_with_feature`
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.
Utf-8 support has been around for a while as an unstable feature but
utf-32 is fairly new. A bunch of LS (like rust-analyzer) added this in
a pinch, but it's pretty broken right now. The performance overhead is
not very large (still a lot better than utf-16). We can switch back
once the ecosystem has matured.
Snippet text elements can contain escape sequences
that must be treated properly. Furthermore snippets
must always escape certain characters (like `}`
or `\`). The function has been updated to account
for that. `text` is now also included with
`anything` to match the grammar and can also
match empty text. To avoid infinite loops the
`non-empty` combinator has been added which is
automatically used in the `one_or_more` and
`zero_or more` combinator where the problemn would
occur.
Previously any remaining text of the snippet that could not be parsed
was ignored. This commit adds the `parse_all` function which reports
an error if any text was not consumed by the parser
