swarm.nvim

Features

Feature	Description
Add cursor below / above	<C-Down> / <C-Up>
Add cursor at next match	<C-n> — like VM's <C-n>
Remove last cursor	<C-p>
Skip current match	<C-x>
Select all occurrences	<leader>A
Cursors on visual lines	<C-m> in visual mode
Exit	<Esc>
User commands	:MCAddDown, :MCAddUp, :MCAddWord, :MCSelectAll, :MCAddVisual, :MCRemoveLast, :MCSkip, :MCCancel

All extra cursors are rendered with extmarks and follow buffer edits automatically. Typing in insert mode, backspace, and enter are replayed on every cursor.

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Requirements

• Neovim ≥ 0.9 (uses vim.on_key, nvim_buf_set_extmark, nvim_set_hl)

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Installation

lazy.nvim

{
  "bernys/swarm.nvim",
  event = "VeryLazy",
  config = function()
    require("swarm").setup()
  end,
}

packer.nvim

use {
  "bernys/swarm.nvim",
  config = function()
    require("swarm").setup()
  end,
}

---

Configuration

require("swarm").setup({
  -- Set to false to define your own keymaps
  default_mappings = true,

  -- Highlight group for virtual cursors
  highlight_cursor = "Swarm",

  -- Highlight group for virtual selections
  highlight_visual = "SwarmVisual",
})

Custom keymaps

require("swarm").setup({ default_mappings = false })

local s   = require("swarm")
local opts = { noremap = true, silent = true }

vim.keymap.set({ "n", "x" }, "<C-n>",     s.add_cursor_word,    opts)
vim.keymap.set({ "n", "x" }, "<C-p>",     s.remove_last_cursor, opts)
vim.keymap.set({ "n", "x" }, "<C-x>",     s.skip_cursor,        opts)
vim.keymap.set({ "n", "x" }, "<C-Down>",  function() s.add_cursor("down") end, opts)
vim.keymap.set({ "n", "x" }, "<C-Up>",    function() s.add_cursor("up") end,   opts)
vim.keymap.set({ "n", "x" }, "<leader>A", s.select_all_word,    opts)
vim.keymap.set("x",          "<C-m>",     s.add_cursors_visual,  opts)
vim.keymap.set("n",          "<Esc>",     s.cancel,             opts)

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Workflow examples

Edit every occurrence of a word

1. Place the cursor on the word.
2. Press <C-n> once — the current word is selected and cursor jumps to the next match.
3. Keep pressing <C-n> to add more cursors.
4. Press <leader>A to select all occurrences at once.
5. Enter insert mode and type; all cursors edit simultaneously.
6. Press <Esc> to finish.

Edit every line in a visual block

1. Select lines with V (linewise visual).
2. Press <C-m> — a cursor is placed at the same column on every selected line.
3. Type your edits.
4. Press <Esc> to finish.

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Architecture

plugin/swarm.lua   ← Neovim plugin entry point, default keymaps
lua/swarm/
  init.lua               ← Public API (add_cursor, cancel, …)
  config.lua             ← User configuration
  state.lua              ← Virtual cursor list + extmark management
  utils.lua              ← Buffer helpers (find occurrences, insert/delete)
  input.lua              ← on_key capture, keystroke replay to cursors
  highlight.lua          ← Default highlight groups

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Highlight groups

Group	Default	Usage
Swarm	purple block	Virtual cursor positions
SwarmVisual	subtle bg	Virtual visual selections
SwarmMain	cyan block	Real cursor while 'Swarm' is active

Override in your colorscheme or after setup():

vim.api.nvim_set_hl(0, "Swarm", { bg = "#ff0000", fg = "#ffffff", bold = true })

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Contributing

PRs welcome! Areas to improve:

• Visual-mode selections on virtual cursors
• Per-cursor registers/yanks
• Regex-based :MCFind command
• Dot-repeat (.) support
• Undo grouping across all cursors

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A Lua-native multiple-cursors plugin for Neovim, inspired by mg979/vim-visual-multi.

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License

MIT