This is the language server implementation for the Elm programming language.
Note for VSCode users: The plugin contains the language-server. No installation necessary.
The server can be installed via npm
(or from source).
npm install -g @elm-tooling/elm-language-server
Then, you should be able to run the language server with the following command:
elm-language-server
Follow the instructions below to integrate the language server into your editor.
First, clone this repo and compile it. npm link
will add elm-language-server
to the PATH
.
git clone [email protected]:elm-tooling/elm-language-server.git
cd elm-language-server
npm install
npm run compile
npm link
Alternative: Install with Nix
elm-languager-server
and its dependencies are available in nixpkgs
.
nix-env -i -A nixpkgs.elmPackages.elm-language-server
You will need to install elm
and elm-test
to get all diagnostics and elm-format
for formatting. Alternatively you can also just install these to your local npm package.json
.
npm install -g elm elm-test elm-format
Or use local versions from your node_modules
directory, if you want to do that you need to set the paths, via the settings (e.g. set elmPath
to ./node_modules/.bin/elm
).
Supports Elm 0.19
Feature | Description |
---|---|
diagnostics | Provided via elm , elm-test and elm-analyse |
formatting | Provided via elm-format and post-processed to only return a diff of changes. This way it should not be as intrusive as running elm-format normal |
codeLenses | Currently only shows if a type alias, custom type or function is exposed from that module |
completions | Show completions for the current file and snippets |
definitions | Enables you to jump to the definition of a type alias, module, custom type or function |
documentSymbols | Identifies all symbols in a document. |
folding | Let's you fold the code on certain Elm constructs |
hover | Shows type annotations and documentation for a type alias, module, custom type or function |
references | Lists all references to a type alias, module, custom type or function |
rename | Enables you to rename a type alias, module, custom type or function |
workspaceSymbols | Identifies all symbols in the current workspace |
selectionRange | Enables navigation by selectionRange (extend selection for e.g.) |
This server contributes the following settings:
elmLS.trace.server
: Enable/disable trace logging of client and server communicationelmLS.elmPath
: The path to yourelm
executable. Should be empty by default, in that case it will assume the name and try to first get it from a local npm installation or a global one. If you set it manually it will not try to load from the npm folder.elmLS.elmFormatPath
: The path to yourelm-format
executable. Should be empty by default, in that case it will assume the name and try to first get it from a local npm installation or a global one. If you set it manually it will not try to load from the npm folder.elmLS.elmTestPath
: The path to yourelm-test
executable. Should be empty by default, in that case it will assume the name and try to first get it from a local npm installation or a global one. If you set it manually it will not try to load from the npm folder.elmLS.elmAnalyseTrigger
:elm-analyse
executed on'change'
,'save'
or'never'
(default:'change'
)
Settings may need a restart to be applied.
elm-analyse
is used for static code analysis. All checks are enabled by default. An (optional) elm-analyse.json
configuration file will be respected, if added to your project.
See its documentation for details regarding configuration
and checks
.
Editor | Diagnostics | Formatting | Code Lenses | Completions | Definitions | Document Symbols | Folding | Hover | References | Rename | Workspace Symbols |
---|---|---|---|---|---|---|---|---|---|---|---|
VSCode | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
VIM CoC | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
VIM LanguageClient | ✔️ | ✔️ | ❔ | ✔️ | ❔ | ❔ | ❔ | ❔ | ❔ | ❔ | ❔ |
VIM ALE | ✔️ | ❌ | ❌ | ❔ | ✔️ | ❌ | ❌ | ✔️ | ✔️ | ❌ | ✔️ |
Kakoune | ✔️ | ✔️ | ❔ | ✔️ | ✔️ | ✔️ | ❔ | ✔️ | ✔️ | ✔️ | ❔ |
Emacs | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ❔ | ✔️ | ✔️ | ✔️ | ✔️ |
Sublime | ✔️ | ✔️ | ❌ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
Just install the elm-tooling/elm-language-client-vscode
plugin from the VSCode MarketPlace
There are general setup instructions and FAQ for Vim.
It's recommended to install syntax highlighting, which also adds the required detection of elm as filetype
. An example vim configuration can be found in elm-vim/vim-config-example.
To enable support with coc.nvim, run :CocConfig
and add the language server config below.
If needed, you can set the paths to elm
, elm-test
and elm-format
with the elmPath
, elmTestPath
and elmFormatPath
variables.
{
"languageserver": {
"elmLS": {
"command": "elm-language-server",
"filetypes": ["elm"],
"rootPatterns": ["elm.json"],
"initializationOptions": {
"elmAnalyseTrigger": "change"
}
}
},
// If you use neovim you can enable codelenses with this
"codeLens.enable": true
}
Much of this is covered in the Example vim configuration section in Coc's readme.
Feature | How to use it |
---|---|
Diagnostics | :CocList diagnostics Configure refresh with "diagnostic.refreshAfterSave": false |
Formatting | :call CocAction('format') |
CodeLenses | Requires Neovim. Add "coc.preferences.codeLens.enable": true to your coc-settings.json through :CocConfig |
Completions | On by default, see Completion with sources for customizations |
Definitions | Provided as <Plug> mapping so that you can set it yourself, e.g. nmap <silent> gd <Plug>(coc-definition) nmap <silent> gy <Plug>(coc-type-definition) |
DocumentSymbols | :CocList outline |
Folding | You must set foldmethod=manual in your vimrc , one set Coc will handle folding with the usual commands, zc , zo , etc |
Hover | :call CocAction('doHover') |
References | Provided as a <Plug> mapping, e.g. nmap <silent> gr <Plug>(coc-references) |
Rename | Provided as a <Plug> mapping, e.g. nmap <leader>rn <Plug>(coc-rename) |
Workspace Symbols | :CocList symbols |
ALE contains the elm_ls
linter.
let g:ale_linters = { 'elm': ['elm_ls'] }
If needed, you can set the paths to elm
, elm-test
and elm-format
. The configuration can be found here
let g:ale_elm_ls_use_global = 1
let g:ale_elm_ls_executable = "/path/to/elm-language-server"
let g:ale_elm_ls_elm_analyse_trigger = 'change'
let g:ale_elm_ls_elm_path = "/path/to/elm"
let g:ale_elm_ls_elm_format_path = "/path/to/elm-format"
let g:ale_elm_ls_elm_test_path = "/path/to/elm-test"
Feature | How to use it |
---|---|
Diagnostics | :ALENext /:ALEPrevious Configure refresh with let g:ale_lint_on_text_changed = 0 let g:ale_lint_on_insert_leave = 1 let g:ale_lint_on_save = 1 |
Formatting | ALE doesn't currently support this through the language server integration, but elm-format is a supported ALE Fixer |
CodeLenses | Not currently supported |
Completions | On by default, see :h ale-completion for more info |
Definitions | :ALEGoToDefinition , :ALEGoToTypeDefinition , see :h ale-go-to-definition and :h ale-go-to-type-definition |
DocumentSymbols | Only workspace symbols are currently supported |
Folding | Not currently supported |
Hover | :ALEHover |
References | :ALEFindReferences |
Rename | Not currently supported |
Workspace Symbols | :ALESymbolSearch <query> |
To use this language server with LanguageClient add the following configuration to you neovim/vim.
let g:LanguageClient_serverCommands = {
\ 'elm': ['elm-language-server'],
\ }
let g:LanguageClient_rootMarkers = {
\ 'elm': ['elm.json'],
\ }
First install kak-lsp, and enable it in the kakrc. One way would be to add these lines to your .config/kak/kakrc file:
eval %sh{kak-lsp --kakoune -s $kak_session}
lsp-enable
Then, assuming installation of elm-language-server
, elm-format
, and elm-test
, add this section to your .config/kak-lsp/kak-lsp.toml
file:
[language.elm]
filetypes = ["elm"]
roots = ["elm.json"]
command = "elm-language-server"
[language.elm.initialization_options]
elmAnalyseTrigger = "change"
The language client is included in lsp-mode, specifically here. See specifically this section for a minimal use-package configuration for lsp-mode.
First install the language server via npm npm i -g @elm-tooling/elm-language-server
Install Elm Syntax Highlighting from Package Control.
Then we also need the LSP Package to be able to connect Sublime to the Language Server.
Add this to your LSP settings under the clients
node:
"elm": {
"command": [
"elm-language-server"
],
"enabled": true,
"languageId": "elm",
"scopes":
[
"source.elm"
],
"syntaxes":
[
"Packages/Elm Syntax Highlighting/src/elm.sublime-syntax"
],
"initializationOptions": {
"elmAnalyseTrigger": "change"
}
}
You should now be able to use the integrations from Sublime.
Please do :) As the best thing about a language server is that multiple clients will improve that way.