replua.nvim

An Emacs-style scratch buffer for executing Lua inside Neovim. replua.nvim opens a dedicated buffer where you can experiment with Lua, call any Neovim API, and see results printed inline -- much like the classic Emacs Lisp interaction mode.

Features

• Opens a scratch buffer (replua://scratch) with Neovim APIs and the current global environment available.
• Evaluate the current line, surrounding block, or the whole buffer.
• Captures both returned values and print() output, appending results as Lua comments.
• Each scratch buffer owns its own Lua environment. Close a buffer (or open a new one with :RepluaOpen!) to start from a clean slate without affecting other replua instances.

Installation

-- lazy.nvim example
{
  "mghaight/replua.nvim",
  config = function()
    require("replua").setup()
  end,
}

If you prefer to manage configuration manually, require the plugin somewhere in your startup files:

require("replua").setup()

The bundled plugin/replua.lua file calls setup() on load, so the commands are available even without manual configuration.

Usage

Open the scratch buffer with:

:RepluaOpen

Need another scratch buffer? Run :RepluaOpen! for a fresh instance.

The default keymaps inside the buffer mirror Emacs-style interactions:

Mapping	Mode	Action
<localleader>e	n	Evaluate the current line
<localleader><CR>	n	Evaluate the surrounding block
<localleader>r	n	Evaluate the entire scratch buffer

Each evaluation appends comment lines such as -- => result or -- print: output, and drops you onto a new blank line ready for more Lua.

Additional commands:

• :RepluaEval — Evaluate the entire scratch buffer.
• :RepluaOpen! — Create a new replua buffer with a fresh environment.
• :RepluaReset — Reset the Lua environment used for evaluation.

Because the environment proxies _G, anything you define becomes available to Neovim instantly. For example:

vim.api.nvim_set_option_value("number", true, { scope = "local", win = 0 })
-- => nil

Configuration

Customize behaviour through setup():

-- example configuration
require("replua").setup({
  open_command = "botright 15split",
  keymaps = {
    eval_line = "<leader>rl",
    eval_block = nil, -- disable
    eval_buffer = "<leader>ra",
  },
  intro_lines = {
    "-- replua.nvim",
    "-- Custom scratch buffer - happy hacking!",
    "",
  },
  print_prefix = "-- -> ",
  result_prefix = "-- => ",
  newline_after_result = true,
  persist_env = true,
})

Any option may be omitted to keep the defaults. Tables are merged, so redefining a single keymap leaves the others untouched.