Steps to Set Up LazyVim with LuaSnip and LaTeX Snippets

1. Fresh Install of LazyVim and Clear Cache

• Follow the LazyVim installation guide: https://www.lazyvim.org/installation
• Clear the cache by running the following commands:

rm -rf ~/.local/share/nvim
rm -rf ~/.local/state/nvim
rm -rf ~/.cache/nvim
rm -rf ~/.config/nvim

2. Update and Install LazyVim Defaults

• Installation link for LazyVim - https://www.lazyvim.org/installation
• After installing LazyVim, ensure that you have updated and installed all the defaults.
• Use the LazyVim extras (use the x option).

3. Install LuaSnip from the Extras Menu

• In the LazyVim extras menu, select and install LuaSnip. This ensures all dependencies are installed correctly.

4. Add LuaSnip Example Snippets

• Paste the following LuaSnip example snippets into your init.lua file:
  • https://github.com/L3MON4D3/LuaSnip/blob/master/Examples/snippets.lua

(Note: You can organize your snippets into separate folders, but for quick testing, you can directly add them this way to verify they work.)

5. Install LaTeX Snippets Plugin

• Install the LaTeX snippets plugin by adding the following code in the lua/plugins/latexsnips.lua file:

return {
    "evesdropper/luasnip-latex-snippets.nvim",
}

• After this, when you load a .tex file, you will have all the LaTeX snippets available.

6. Configure LuaSnip and Key Mappings in init.lua

• Add the following configuration at the start of your init.lua file to require LuaSnip and set up key mappings:

-- Require LuaSnip
local luasnip = require("luasnip")

-- Configure key mappings
vim.keymap.set({"i", "s"}, "<Tab>", function()
    if luasnip.expand_or_jumpable() then
        luasnip.expand_or_jump()
    else
        return "<Tab>"
    end
end, {silent = true, expr = true})

vim.keymap.set({"i", "s"}, "<S-Tab>", function()
    if luasnip.jumpable(-1) then
        luasnip.jump(-1)
    else
        return "<S-Tab>"
    end
end, {silent = true, expr = true})

7. Setup nvim-cmp for LuaSnip Tab Expansion

• Add the following snippet under the previous set up nvim-cmp to use <Tab> for expanding LuaSnip snippets and <S-Tab> for jumping backward:

-- Setup nvim-cmp.
local cmp = require'cmp'
local luasnip = require'luasnip'

cmp.setup({
    mapping = {
        -- Use <Tab> to expand snippets
        ['<Tab>'] = cmp.mapping(function(fallback)
            if luasnip.expand_or_jumpable() then
                luasnip.expand_or_jump()
            else
                fallback()  -- fall back to normal tab functionality
            end
        end, { 'i', 's' }),

        -- Use <S-Tab> to jump backward in snippets
        ['<S-Tab>'] = cmp.mapping(function(fallback)
            if luasnip.jumpable(-1) then
                luasnip.jump(-1)
            else
                fallback()
            end
        end, { 'i', 's' }),
    },
})

8. Important Notes

• This configuration allows you to use <Tab> as the expander for LuaSnip snippets. However, it does not provide partial snippet completion.
• For example, to expand a LaTeX matrix snippet, you must type the entire trigger (e.g., mat) and then press <Tab>. It will not complete with a partial trigger like ma followed by <Tab>.