* 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.
There was an issue with autocompletion of a path with a space in it.
Before:
:o test\ dir -> <TAB> -> test\ dirfile1
After:
:o test\ dir -> <TAB> -> test\ dir\file1
Currently, when forward deleting (`delete_char_forward` bound to `del`,
`delete_word_forward`, `kill_to_line_end`) the cursor is moved to the
left in append mode (or generally when the cursor is at the end of the
selection). For example in a document `|abc|def` (|indicates selection)
if enter append mode the cursor is moved to `c` and the selection
becomes: `|abcd|ef`. When deleting forward (`del`) `d` is deleted. The
expectation would be that the selection doesn't shrink so that `del`
again deletes `e` and then `f`. This would look as follows:
`|abcd|ef`
`|abce|f`
`|abcf|`
`|abc |`
This is inline with how other editors like kakoune work.
However, helix currently moves the selection backwards leading to the
following behavior:
`|abcd|ef`
`|abc|ef`
`|ab|ef`
`ef`
This means that `delete_char_forward` essentially acts like
`delete_char_backward` after deleting the first character in append
mode.
To fix the problem the cursor must be moved to the right while deleting
forward (first fix in this commit). Furthermore, when the EOF char is
reached a newline char must be inserted (just like when entering
appendmode) to prevent the cursor from moving to the right
