spacemacs/layers/+lang/erlang/README.org

Erlang layer

• Description
  • Features:
• Install
  • Layer
  • Choosing a backend
• Configuration
  • erlang-mode
  • LSP
• Key bindings
  • erlang-mode
  • LSP

Description

This layer adds support for Erlang.

Enabling Lsp-mode brings IDE like features following Language Server Protocol, through erlang_ls

Features:

• Syntax highlighting
• Syntax checking via Flycheck integration
• Auto-completion via Company integration
• Code Completion
• Go To Definition
• Go To Implementation for OTP Behaviours
• Signature Suggestions
• Compiler Diagnostics
• Dialyzer Diagnostics
• Elvis Diagnostics
• Edoc
• Navigation for Included Files
• Find/Peek References
• Outline
• Workspace Symbols
• Code Folding

Install

Layer

To use this configuration layer, add it to your ~/.spacemacs. You will need to add erlang to the existing dotspacemacs-configuration-layers list in this file.

Choosing a backend

company-erlang uses gtags to provide a very basic working environment, it is the default backend.

You can improve the IDE-like experience by choosing the lsp backend, to do so, first add the lsp layer to dotspacemacs-configuration-layers, then, set the layer variable erlang-backend:

  (erlang :variables erlang-backend 'lsp)

Alternatively the lsp backend will be automatically chosen if the layer lsp is used and you did not specify any value for erlang-backend.

Configuration

erlang-mode

To find the manual page for the function under the cursor you can either set erlang-man-root-dir to erlang man root directory path in the layer definition:

  (erlang :variables erlang-man-root-dir "*path_to_folder*/otp_22/lib/erlang/man")

or let erlang-mode download it by executing M-x erlang-man-download-ask.

LSP

The lsp backend uses erlang_ls as its language server implementation.

Clone the project to your system and compile it:

  make

Note: Ensure you have erlang_ls in your PATH…

You can install it:

  make install

Key bindings

erlang-mode

Key binding	Description
C-c C-a	Align arrows ("->")
C-c C-c	Comment region
C-c C-d	Display function manual at point
C-c C-j	Generate a new clause
C-c C-q	Indent function
C-c C-u	Uncomment region
C-c C-y	Insert, at the point, the argument list of the previous clause.
C-c C-z	Display the erlang-shell or start a new
C-c M-a	Move backward to previous start of clause.
C-c M-e	Move to the end of the current clause.
C-c M-h	Put mark at end of clause, point at beginning.

LSP

You will find an overview of all the key bindings on the lsp layer description.