luasnip-latex-snippets

A port of Gilles Castel's snippets for the LuaSnip Engine.

Why?

UltiSnips felt unbearably slow. See neovim/neovim#7063 and https://github.com/SirVer/ultisnips/issues?q=label%3A%22neovim+only%22+is%3Aclosed.

Installation

Depends on vimtex to determine if the cursor is within math mode. Alternatively, you can use nvim-treesitter (experimental) by passing { use_treesitter = true } to the setup call.

It's necessary to enable autosnippets in luasnip: require("luasnip").config.setup { enable_autosnippets = true }.

Can be installed like any neovim plugin. If using wbthomason/packer.nvim:

use {
  "iurimateus/luasnip-latex-snippets.nvim",
  -- vimtex isn't required if using treesitter
  requires = { "L3MON4D3/LuaSnip", "lervag/vimtex" },
  config = function()
    require'luasnip-latex-snippets'.setup()
    -- or setup({ use_treesitter = true })
    require("luasnip").config.setup { enable_autosnippets = true }
  end,
}

Configuration

{
  use_treesitter = false, -- whether to use treesitter to determine if cursor is in math mode; if false, vimtex is used
  allow_on_markdown = true, -- whether to add snippets to markdown filetype
}

Misc

The following convention, from SirVer/ultisnips, is used for naming lua tables and respective files:

A: Automatic snippet expansion - snippets will activate as soon as their trigger
matches.

w: Word boundary - With this option the snippet trigger will match when the
trigger is a word boundary character. This is the default behavior.

b: Beginning of line expansion - A snippet with this option is expanded only if
the trigger is the first word on the line (i.e., only whitespace precedes the
trigger).

Note that the regex term used in LuaSnip is misleading: it is not a POSIX regexp. What's actually being used is Lua pattern matching, which has some limitations. In particular, it lacks positive lookbehind and alternation |. The first which is used in postfix completions (e.g. match delta, but not \delta) and can be handled with simple functions. The second was solved by splitting and/or partially rewriting the expressions.

Adding your own snippets / overrides

See discussion #3 (reply in thread)

local ls = require("luasnip")
local utils = require("luasnip-latex-snippets.util.utils")
local not_math = utils.not_math() -- pass true if using Treesitter

-- set a higher priority (defaults to 0 for most snippets)
local snip = ls.parser.parse_snippet(
  { trig = "mk", name = "Math", condition = not_math, priority = 10 },
  "$ ${1:${TM_SELECTED_TEXT}} $$0"
)

ls.add_snippets("tex", { snip }, {
  type = "autosnippets",
})

Roadmap

• Tests