/LuaSnip

Snippet Engine for Neovim written in Lua.

Primary LanguageLuaApache License 2.0Apache-2.0

LuaSnip

LuaSnip

javadoc.mp4

Features

  • Tabstops
  • Text-Transformations using Lua functions
  • Conditional Expansion
  • Defining nested Snippets
  • Filetype-specific Snippets
  • Choices
  • Dynamic Snippet creation
  • Regex-Trigger
  • Autotriggered Snippets
  • Easy Postfix Snippets
  • Fast
  • Parse LSP-Style Snippets either directly in lua, as a vscode package or a snipmate snippet collection.
  • Expand LSP-Snippets with nvim-compe (or its' successor, nvim-cmp (requires cmp_luasnip))
  • Snippet history (jump back into older snippets)
  • Resolve filetype at the cursor using Treesitter

Drawbacks

  • Snippets that make use of the entire functionality of this plugin have to be defined in Lua (but 95% of snippets can be written in lsp-syntax).

Requirements

Neovim >= 0.7 (extmarks) jsregexp for lsp-snippet-transformations (see here for some tips on installing it).

Setup

Install

  • With your preferred plugin manager i.e. vim-plug, Packer or lazy
    Packer:

    use({
	"L3MON4D3/LuaSnip",
	-- follow latest release.
	tag = "v2.*", -- Replace <CurrentMajor> by the latest released major (first number of latest release)
	-- install jsregexp (optional!:).
	run = "make install_jsregexp"
})

    lazy:

    {
	"L3MON4D3/LuaSnip",
	-- follow latest release.
	version = "v2.*", -- Replace <CurrentMajor> by the latest released major (first number of latest release)
	-- install jsregexp (optional!).
	build = "make install_jsregexp"
}

    vim-plug:

    " follow latest release and install jsregexp.
Plug 'L3MON4D3/LuaSnip', {'tag': 'v2.*', 'do': 'make install_jsregexp'} " Replace <CurrentMajor> by the latest released major (first number of latest release)

    Check the Releases-section to the right for the latest major version.

  • LuaSnip uses Semantic Versioning (with some leeway, big patches might end up as a Minor version)!
    Releases will be tagged as vMajor.Minor.Patch, we recommend following the latest Major release.
    Consider watching the repos releases so you're notified when a new version becomes available.

Keymaps

In vimscript, with <Tab> for jumping forward/expanding a snippet, <Shift-Tab> for jumping backward, and <Ctrl-E> for changing the current choice when in a choiceNode...

" press <Tab> to expand or jump in a snippet. These can also be mapped separately
" via <Plug>luasnip-expand-snippet and <Plug>luasnip-jump-next.
imap <silent><expr> <Tab> luasnip#expand_or_jumpable() ? '<Plug>luasnip-expand-or-jump' : '<Tab>' 
" -1 for jumping backwards.
inoremap <silent> <S-Tab> <cmd>lua require'luasnip'.jump(-1)<Cr>

snoremap <silent> <Tab> <cmd>lua require('luasnip').jump(1)<Cr>
snoremap <silent> <S-Tab> <cmd>lua require('luasnip').jump(-1)<Cr>

" For changing choices in choiceNodes (not strictly necessary for a basic setup).
imap <silent><expr> <C-E> luasnip#choice_active() ? '<Plug>luasnip-next-choice' : '<C-E>'
smap <silent><expr> <C-E> luasnip#choice_active() ? '<Plug>luasnip-next-choice' : '<C-E>'

... or in lua, with a different set of keys: <Ctrl-K> for expanding, <Ctrl-L> for jumping forward, <Ctrl-J> for jumping backward, and <Ctrl-E> for changing the active choice.

vim.keymap.set({"i"}, "<C-K>", function() ls.expand() end, {silent = true})
vim.keymap.set({"i", "s"}, "<C-L>", function() ls.jump( 1) end, {silent = true})
vim.keymap.set({"i", "s"}, "<C-J>", function() ls.jump(-1) end, {silent = true})

vim.keymap.set({"i", "s"}, "<C-E>", function()
	if ls.choice_active() then
		ls.change_choice(1)
	end
end, {silent = true})

nvim-cmp's wiki also contains an example for setting up a super-tab-like mapping.

Add Snippets

Check out the doc for a general explanation of the loaders and their benefits. The following list serves only as a short overview.

  • VS Code-like: To use existing VS Code style snippets from a plugin (eg. rafamadriz/friendly-snippets) simply install the plugin and then add

    require("luasnip.loaders.from_vscode").lazy_load()

    somewhere in your nvim-config. LuaSnip will then load the snippets contained in the plugin on startup. You can also easily load your own custom vscode style snippets by passing the path to the custom snippet-directory to the load function:

    -- load snippets from path/of/your/nvim/config/my-cool-snippets
require("luasnip.loaders.from_vscode").lazy_load({ paths = { "./my-cool-snippets" } })

    For more info on the VS Code loader, check the examples or documentation.

  • SnipMate-like: Very similar to VS Code packages; install a plugin that provides snippets and call the load-function:

    require("luasnip.loaders.from_snipmate").lazy_load()

    The SnipMate format is very simple, so adding custom snippets only requires a few steps:

    • add a directory beside your init.vim (or any other place that is in your runtimepath) named snippets.
    • inside that directory, create files named <filetype>.snippets and add snippets for the given filetype in it (for inspiration, check honza/vim-snippets). 
      # comment
snippet <trigger> <description>
<snippet-body>
snippet if C-style if
if ($1)
	$0

    Again, there are some examples and documentation.

  • Lua: Add the snippets by calling require("luasnip").add_snippets(filetype, snippets). An example for this can be found here.
    This can also be done much cleaner, with all the benefits that come with using a loader, by using the loader for lua

There's also a repository collecting snippets for various languages, molleweide/LuaSnip-snippets.nvim

Documentation

Getting started

You have two main choices: use SnipMate/VS Code snippets (easier) or write snippets in Lua (more complex but also more feature-rich). Here are some suggestions for getting started in either case:

  • SnipMate or VS Code snippets: if you only want to write/load SnipMate or VS Code snippets and ignore Lua snippets (and this is definitely recommended if you don't yet need Lua snippets' more complicated features), check out the sections on loading VS Code or SnipMate packages in DOC.md. Of those two, SnipMate is definitely the more comfortable way of writing snippets.
  • Lua snippets: we suggest first watching or reading one of the introductory guides in the Resources for new users section below. After getting familiar with the basics, you should check out the important LuaSnip features in the following list:
    • config: Notable: region_check_events for jumping to the end of snippets the cursor is no longer inside of, delete_check_events for cleaning up snippets whose text was deleted, and enable_autosnippets to enable automatic snippet expansion.
    • extras: This module contains many functions that make writing snippets significantly easier; fmt and lambda are especially useful.
    • lua-loader: A very useful way to load snippets, more comfortable than calling add_snippets.
      Also supports hot reload (limited to buffers in the same NeoVim instance as the edited file) and jumping to the files that provide snippets to the current buffer.
    • Advanced nodes: functionNode, dynamicNode, choiceNode and restoreNode.
      Instead of reading about them in the doc, the first three are explained very well in this video by TJ DeVries.

Official docs and examples

Note: instead of immediately reading the official documentation, you may want to check out the Resources for new users section below since the docs are written more as a reference manual than as a tutorial for new users.

  • DOC.md is the main documentation—it gives an overview of how to write snippets, explains the role and use case of each LuaSnip node, shows how to load snippets from Lua, VS Code, and SnipMate formats, and covers the available LuaSnip API.
  • :help luasnip.txt is a plain text version of DOC.md available with Neovim's :help feature.
  • The file Examples/snippets.lua contains many example snippets written in Lua—we highly recommend looking through (or better yet, :luafileing) these example snippets before using LuaSnip's advanced features.
  • The Wiki contains some useful LuaSnip extensions and some examples of advanced snippets and configs.
  • Configuration is documented in DOC.md as well.

【中文版】DOC in Chinese is here.

Resources for new users

Here are some LuaSnip videos and tutorials on the Web:

Inspired by vsnip.vim