Expert

The official language extension for Expert, Elixir's offical language server.

⚠️ Early Access ⚠️

Expert is currently in pre-1.0 early access. Pull requests and issues are welcome in the offical GitHub repo.

Features

The Expert extension consists of the following components and features:

Syntax Highlighting Grammars

TextMate grammars that provide syntax highlighting for Elixir source code files (.ex and .exs), including Embedded Elixir (*.eex). For syntax highlighting in HTML-aware Embedded Elixir (*.heex), please install the Phoenix Framework extension.

Expert Language Server

Code completions
On-Demand code formatting (triggered by Alt + Shift + F hotkey or enabling editor.formatOnSave)
Diagnostics (In-editor annotations of compiler warnings and errors)
Code actions (extract to variable, extract to alias, etc)
Symbol search (Command + T hotkey)
File outlines
Go to definition/reference
In-editor documentation (on completion and hover)

Using the extension

Expert releases are currently published nightly. This extension will automatically download and install the latest relased from GitHub when starting up.

Alternatively, you may opt to build Expert from source and point this extension at it via the expert.server.releasePathOverride configuration option.

Configuration

expert.server.releasePathOverride

Tells the extension to use a local release of the Expert language server instead of the automatically installed one. This path should point to Expert's executable, typically located at /path/to/expert/apps/expert/burrito_out/expert_darwin_arm64.

expert.notifyOnServerAutoUpdate

Controls whether notifications are shown after automatic installs of new Expert versions. Defaults to true.

Editor Configuration

The extension provides a language configuration for Elixir which marks do/end and fn/end as brackets. Among other things, this enables colorization of do/end and fn/end with VSCode's editor.bracketPairColorization.enabled setting. While this can be helpful when searching for a do's corresponding end, some users may prefer to use the standard keyword coloring, while still highlighting parenthesis and other brackets. This can be achieved by adding the following to your VSCode configuration.

"editor.bracketPairColorization.enabled": true,
"[elixir]": {
  "editor.language.colorizedBracketPairs": [
    ["{", "}"],
    ["[", "]"],
    ["(", ")"]
  ]
}

Compatability

Expert tentatively targets support for Elixir >= 1.15.3 and OTP >= 25.0.

Troubleshooting

Expert outputs logs to two different files:

expert.log: Contains logs for the language server node, which handles all the LSP communication, code intelligence, etc.
project.log: Contains logs for the project node, which handles loading and compiling your project.

Additionally, the Expert channel in VSCode's Output tab may contain some pertinent information, notably if/when Expert fails to start before log files are initialized.

Frequent issues and questions

I'm not getting syntax highlighting for HEEx

The syntax highlighting grammar for HEEx (~H sigils and *.heex files) is maintained and provided by the Phoenix Framework extension. While HEEx is quite similar to EEx, it isn't part of Elixir's standard library.

Support

If you have questions or need help, please refer to one of the following channels:

The #editor-tooling channel in the Elixir Discord server

Acknowledgements

The Expert extension was derived from the vscode-lexical plugin authored by Étienne Lévesque (aka Blond11516).

Expert LSP