ErlLS

Erlang language server.

Supported LSP features

• textDocument/definition
  • Module
  • Function
  • Type
  • Record
  • Macro
  • Variable
  • Include file
• textDocument/formatting
  • Formatting documents by using efmt
• textDocument/completion
  • Fully qualified function name
  • Fully qualified type name
  • Record name
  • Record field name
• textDocument/publishDiagnostics (when received textDocument/{didOpen,didSave})
  • Parse errors by efmt
  • Lint checks
• textDocument/rename
• textDocument/semanticTokens/full
• textDocument/semanticTokens/range
• textDocument/documentHighlight
  • Variable
• textDocument/hover
  • NOTE: Only the -doc and -moduledoc attributes are supported (i.e., doc comments are not supported)

Editor integrations

ErlLS can be used with any LSP clients. Here are a few examples.

Visual Studio Code / Visual Studio Code for the Web

Please install erlls extension.

There is no need to install the erlls binary using the $ cargo install command as the extension already includes the WebAssembly build.

Settings (settings.json)

To include the Erlang/OTP applications in the search target, please specify the directory as follows:

{
    "erlls.erlLibs": "/usr/local/lib/erlang/lib/:_checkouts:_build/default/lib"
}

NOTE:

• The actual path may vary depending on the environment.
• In VSCode Web, it's not possible to search applications located outside of the workspace.

Emacs (lsp-mode)

1. Install erlls command.

$ cargo install erlls

2. Add the following code to your .emacs file.

(with-eval-after-load 'lsp-mode
  (add-to-list 'lsp-language-id-configuration
               '(erlang-mode . "erlang")))

(lsp-register-client
 (make-lsp-client :new-connection (lsp-stdio-connection "erlls")
                  :activation-fn (lsp-activate-on "erlang")
                  :priority -1
                  :server-id 'erlls))