Setup Neovim for Elixir

Table of Contents

I have been using Vim/Neovim as my primary IDE for the last 5 years and developing in Elixir for the past 2 years and a half or so. In this article, I’ll try to explain my current setup with its plugin and global configuration. I’ll also include as many tips as possible so that you can boost your productivity using this fantastic editor. This article is aimed at Neovim users but you can adapt everything to vim.

Plugin manager
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First of all, we need a plugin manager because downloading manually every time you need to use vim on a new session becomes annoying pretty quickly. I personnaly use vim-plug but Pathogen or other choices are ok too !

I like to have my plugs separated from the rest of my config so put

source $HOME/.config/nvim/plug.vim

at the top of your init.vim file.

In your plug.vim file, copy the following to install plug-vim if absent.

let vimplug_exists=expand('~/.config/nvim/autoload/plug.vim')

if !filereadable(vimplug_exists)
  if !executable("curl")
    echoerr "You have to install curl or first install vim-plug yourself!"
    execute "q!"
  endif
  echo "Installing Vim-Plug..."
  echo ""
  silent exec "!\curl -fLo " . vimplug_exists . " --create-dirs https://raw.githubusercontent.com/junegunn/vim-plug/master/plug.vim"
  let g:not_finish_vimplug = "yes"

  autocmd VimEnter * PlugInstall
endif

To download and use plugins, we need to add the following to plug.vim :

call plug#begin('~/.config/nvim/plugged')
Plug 'tpope/vim-fugitive'
call plug#end()

The line Plug 'tpope/vim-fugitive' is an example of a plugin you can install. You need to put the keyword Plug followed by the plugin’s github repository.

With this, we have the plugin manager and we can dive into the exciting parts !

The basics
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I’ll try to not spend too much time on these but we still need to use a few basic plugins for project management and other purposes. Here is the list :

  Plug 'tpope/vim-surround'
  Plug 'scrooloose/nerdtree'
  Plug 'Xuyuanp/nerdtree-git-plugin'
  Plug 'scrooloose/nerdcommenter'
  Plug 'tpope/vim-fugitive'
  Plug 'jiangmiao/auto-pairs'
  Plug 'bling/vim-airline'
  Plug 'nathanaelkane/vim-indent-guides'

In order, these will:

Change the characters surrounding an object (line/word/paragraph/other)
Display a file explorer of the current directory
Add git functionnalities to the previous file explorer
Comment/uncomment more easily
Add git functionnalities such as git vertical diff to resolve merge conflicts with ease
Autopairs certain non alphanumerical characters such as parenthesis, quotes, curly braces …
Display a status/tabline
Display indent guides

For the configuration, here are a few very basics config parameters :

"" Encoding
set encoding=utf-8
set fileencoding=utf-8
set fileencodings=utf-8

" Basic stuff
let mapleader=","
set foldmethod=indent

"" Tabs. May be overridden by autocmd rules
set tabstop=2
set softtabstop=0
set shiftwidth=2
set expandtab

"" Fix backspace indent
set backspace=indent,eol,start

"" Enable hidden buffers
set hidden

"" Searching
set nohlsearch
set incsearch
set ignorecase
set smartcase

" session management
let g:session_directory = "~/.config/nvim/session"
let g:session_autoload = "no"
let g:session_autosave = "no"
let g:session_command_aliases = 1
set nobackup
set noswapfile

set nocompatible

There is a million other settings that you can tweak but for now, it will be enough !

You might also want to add a theme of your choice such as nord/gruvbox/dracula…

Syntax Highlighting
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For syntax highlighting, I use vim-elixir so add the following in your plug.vim file:

Plug 'vim-editors/vim-elixir'

It also handles automatic indentation which is always handy. You must have the following in your init.vim file for it to work properly:

syntax on
filetype plugin indent on

Snippets
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Snippets are small templates for commonly used code that you can fill in on the fly. It’s surprisingly powerful and doesn’t need much configuration.

First, we need a plugin to handle snippets. I like to use Ultisnips to manage them. Add to your plug.vim file:

Plug 'sirver/ultisnips'
Plug 'honza/vim-snippets'

And to your init.vim:

" Snippets
let g:UltiSnipsExpandTrigger="<c-j>"
let g:UltiSnipsJumpForwardTrigger="<c-j>"
let g:UltiSnipsJumpBackwardTrigger="<c-b>"

For example, I can just type mod and press ctrl + j and it will complete it to

defmodule name do
end

with the cursor on name and name selected so I can just keep on typing to change to name of the module.

There is a lot of other snippets ready to be used. If you want to consult them or edit them, type :UltiSnipsEdit with an elixir file opened.

Tags and autocompletion
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Tags are very powerful and helps you navigate big projects with more fluidity. Autocompletion is also a pretty basic feature for any IDE which respects itself.
The plugin I use is alchemist and it’s fantastic! The only downside I have with it is I can’t seem to jump to the definition of a module or function in a new tab. For your plug.vim file:

  Plug 'slashmili/alchemist.vim'
  Plug 'Shougo/deoplete.nvim', { 'do': ':UpdateRemotePlugins' }

And for your init.vim file:

" Deoplete config
let g:deoplete#enable_at_startup=1
call deoplete#custom#option('ignore_sources', {'_': ['around', 'buffer']})

To jump to the definition of the function/module/macro your cursor is on, just press ctrl + ]. If you want to come back to where you were before, press ctrl + t. It requires to have your project compiled whether with iex -S mix or mix phoenix.server. For autocompletion, just press ctrl + x followed by ctrl + o to open a contextual menu with the different options.

Conclusion
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Vim is a very powerful editor and with only a few plugins, you can make it usable even for big projets while retaining its speed and lightweight.
If you want to see the rest of my configuration, head over to my dotfiles !

Plugin manager#

The basics#

Syntax Highlighting#

Snippets#

Tags and autocompletion#

Conclusion#