Elixir layer

Table of ContentsClose

1. Description
- 1.1. Features:
2. Install
- 2.1. Layer
- 2.2. Choosing a backend
  - 2.2.1. Feature comparison in backends
3. Configuration
4. Key bindings
- 4.1. Alchemist
- 4.2. LSP
  - 4.2.1. Debugging

1. Description

This layer adds support for Elixir.

Alchemist brings the Elixir tooling to Emacs and comes with a bunch of features. Lsp-mode brings IDE like features following Language Server Protocol, through elixir-ls

As Alchemist is no longer maintained, elixir-ls is a preferred solution, even though it has less features at the moment.

1.1. Features:

Powerful IEx integration
Mix integration
Compile & Execution of Elixir code
Inline code evaluation
Documentation lookup
Definition lookup
Smart code completion
Elixir project management
Integration with company-mode
Flycheck support for credo
Flycheck support for test results
Interactive debugger using dap-mode

2. Install

2.1. Layer

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

2.2. Choosing a backend

To choose a default backend set the layer variable elixir-backend:

(elixir :variables elixir-backend 'alchemist)

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

Backend can be chosen on a per project basis using directory local variables (files named .dir-locals.el at the root of a project), an example to use the lsp backend:

;;; Directory Local Variables
;;; For more information see (info "(emacs) Directory Variables")

((elixir-mode (elixir-backend . lsp)))

Note: you can easily add a directory local variable with SPC f v d.

The available options are:

symbol	description
'alchemist	Default
'lsp	elixir-ls package

2.2.1. Feature comparison in backends

features	Alchemist	Lsp
Powerful IEx integration	yes	no
Mix integration	yes	no
Compile & Execution of Elixir code	yes	no
Inline code evaluation	yes	no
Documentation lookup	yes	yes
Definition lookup	yes	yes
Smart code completion	yes	yes
Elixir project management	yes	no
Integration with `company-mode`	yes	yes
Flycheck support	yes	yes

3. Configuration

3.1. Flycheck

Note: since flycheck checkers are slow, the checks are enabled only at save time.

3.1.1. Credo

You need to install credo into your project. For this, add the following snippet to dependencies of your project (in file mix.exs):

{:credo, "~> 0.5", only: [:dev, :test]}

Then run in your shell:

$ mix deps.get

For more info about mix see.

You can tell flycheck-credo to call credo with the '–strict' argument.

(setq flycheck-elixir-credo-strict t)

3.1.2. Dogma

In order to lint your code, you also need to install dogma into your project. For this, add the following snippet to the dependencies in your mix.exs file:

{:dogma, "~> 0.1", only: [:dev]}

Then run in your shell:

$ mix deps.get

3.2. Language server protocol

The lsp backend uses elixir-ls as its language server implementation Clone the project to your system and follow the building instructions here. Or the lsp-elixir fork, which is actively maintained as well. A third choice would be lexical which is said to be working especially well in bigger projects. For all of these some config must be applied in your dotfile.

For elixir-ls this would be:

(elixir :variables elixir-backend 'lsp
                   elixir-ls-path "*path to folder*/elixir-ls/release")

For lexical this would be:

(elixir :variables elixir-backend 'lsp
                   lsp-elixir-server-command '("*path to folder*/lexical/bin/start_lexical.sh"))

3.3. Debugger

For lsp backend only

lsp backend supports debugging of your elixir project through dap simply follow dap layer installation and configuration instructions as well as make sure to read this elixir-ls debugger support note

4. Key bindings

4.1. Alchemist

4.1.1. Refcard

You find and overview of all the key bindings on the Alchemist-Refcard.

4.1.2. Help

Key binding	Description
`SPC m h :`	Run custom search for help
`SPC m h h`	Show help of the current expression
`SPC m h H`	Toggle through search history
`SPC m h r`	Show help for current region

4.1.3. Mix

Key binding	Description
`SPC m m :`	Prompt for a `mix` command
`SPC m m c`	Compile the whole application
`SPC m m h`	Show help for a specific `mix` command
`SPC m m x`	Run the given expression in the Elixir application context

4.1.4. Project

Key binding	Description
`SPC m g t`	Toggle between a file and its tests in the current window.
`SPC m g T`	Toggle between a file and its tests in other window.

4.1.5. Evaluation in place

Key binding	Description
`SPC m e b`	Evaluate buffer
`SPC m e B`	Evaluate buffer and insert result
`SPC m e l`	Evaluate current line
`SPC m e L`	Evaluate current line and insert result
`SPC m e r`	Evaluate region
`SPC m e R`	Evaluate region and insert result

4.1.6. REPL interactions

Key binding	Description
`SPC m s c`	Compiles the current buffer in the IEx process.
`SPC m s i`	Start an `iex` inferior process
`SPC m s I`	Start an IEx process with mix (`iex -S mix`)
`SPC m s l`	Send current line to REPL buffer
`SPC m s L`	Send current line to REPL buffer and focus it in `insert state`
`SPC m s m`	Reloads the module in the current buffer in your IEx process
`SPC m s r`	Send region to REPL buffer
`SPC m s R`	Send region to REPL buffer and focus it in `insert state`

4.1.7. Tests

Key binding	Description
`SPC m g t`	Open the test file for current buffer
`SPC m t a`	Run all the tests
`SPC m t b`	Run all the tests from current buffer
`SPC m t B`	Run all the tests from current file; if test file not found, after confirm, create it
`SPC m t f`	Choose test file to run
`SPC m t t`	Run test under point
`SPC m t r`	Rerun the last test
`SPC m t n`	Jump to next test
`SPC m t N`	Jump to previous test
`SPC m t s`	Run stale tests (`mix test --stale`)
`SPC m t R`	Toggle test report window
`SPC m t F`	Open project test directory and list all test files.

4.1.8. Compile

Key binding	Description
`SPC m c :`	Run a custom compile command with `elixirc`
`SPC m c b`	Compile the current buffer with elixirc. `elixirc`
`SPC m c f`	Compile the given filename with `elixirc`

4.1.9. Execute

Key binding	Description
`SPC m x :`	Run a custom execute command with `elixir`
`SPC m x b`	Run the current buffer through `elixir`
`SPC m x f`	Run `elixir` with the given filename

4.1.10. Code Definition Jump

Key binding	Description
`SPC m g g`	Jump to the elixir expression definition at point.
`SPC m .`	Jump to the elixir expression definition at point.
`SPC m g b`	Pop back to where `SPC m g g` was last invoked.
`SPC m ,`	Pop back to where `SPC m g g` was last invoked.
`SPC m g n`	Jump to next symbol definition
`SPC m g N`	Jump to previous symbol definition
`SPC m g j`	Choose which symbol definition to jump to

4.1.11. Hex (packages)

Hex is the package manager for Elixir & Erlang ecosystem. See https://hex.pm.

Key binding	Description
`SPC m X i`	Display Hex package information for the package at point
`SPC m X r`	Display Hex package releases for the package at point
`SPC m X R`	Display Hex package releases for a certain package
`SPC m X I`	Display Hex package info for a certain package
`SPC m X s`	Search for Hex packages

4.1.12. Macro expand

Key binding	Description
`SPC m o l`	Macro expand once the Elixir code on the current line
`SPC m o L`	Macro expand once the Elixir code on the current line and insert the result
`SPC m o k`	Macro expand completely the Elixir code on the current line
`SPC m o K`	Macro expand completely the Elixir code on the current line and insert the result
`SPC m o i`	Macro expand once the Elixir code on marked region
`SPC m o I`	Macro expand once the Elixir code on marked region once and insert the result
`SPC m o r`	Macro expand completely the Elixir code on marked region
`SPC m o R`	Macro expand completely the Elixir code on marked region and insert the result

4.1.13. Formatting

Key binding	Description
`SPC m =`	Format the current buffer

4.1.14. Debugging

Key binding	Description
`SPC m d b`	Toggle IEx.pry breakpoint

4.2. LSP

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

4.2.1. Debugging

Using the dap layer you'll get access to all the DAP key bindings, see the complete list of key bindings on the dap layer description.