Embedded Neovim

A text object, visual mode and undo, inside a cell

With editor = "nvim" in your config, jOtter runs a hidden nvim --embed in the background and hands it every key you type in a cell. Neovim does the editing; jOtter still draws everything. You get Neovim’s full editing: operators and text objects (dw, ci(), visual modes, counts, registers, macros, . repeat and your own mappings.

editor = "nvim"

Neovim must be on your PATH. If it’s missing, or it crashes, jOtter switches to the builtin editor and says so in the status line. Text you were typing is kept.

How it behaves

Each cell gets its own Neovim buffer, so undo history and marks survive switching between cells.
The buffer’s filetype is set from the cell (python, markdown, …), so filetype plugins and settings apply.
: and / command lines appear in jOtter’s status line as you type them.
:w saves the cell into the notebook and the notebook to disk, like w outside the cell. If the file changed on disk since you opened or saved it, jOtter refuses; :w! saves anyway, like W.
:wq, :x and ZZ save the same way and leave the cell. :q leaves the cell and keeps the edit without saving the file. :q! and ZQ leave it and throw the edit away.
Esc in normal mode leaves the cell, as in the builtin editor, and Shift+Enter runs it.

Your config and plugins

By default Neovim loads your init.lua or init.vim and plugins. Before your config runs, jOtter sets g:jotter = 1, so you can skip whatever makes no sense inside a cell:

-- options, keymaps and editing plugins load everywhere
require('options')
require('keymaps')

if not vim.g.jotter then
  -- statusline, dashboard, file explorer, pickers: only outside jOtter
  require('ui')
end

Or guard individual plugins, for example with lazy.nvim:

{ 'nvim-lualine/lualine.nvim', cond = not vim.g.jotter },

Set nvim_user_config = false to start a clean Neovim (-u NONE) instead.

What isn’t drawn

jOtter only shows the cell’s text. Neovim runs without a user interface attached, so nothing it would draw in a window of its own appears: pickers (Telescope, fzf-lua), floating hovers and diagnostics, file explorers, splits and the command-line window.

If such a plugin opens a window anyway, jOtter notices right after the key, closes the window, returns to the cell and says so in the status line. Your cell text is never touched, but the plugin’s action is lost. Popups that don’t take focus, such as nvim-cmp’s completion menu, are simply invisible. jOtter’s own completion works with this backend.

The fix for all of these is the vim.g.jotter guard above.