A Neovim plugin for changing keyword case.

Coerce is a Neovim plugin that enables you to quickly change a keyword’s case. Coerce’s framework is also capable of any short-text, single-command text manipulation, e.g., turning selected text into its numeronym.

Example session

⚡️ Requirements

• Neovim 0.9+
• Required plugin dependencies:
  • Coop
• Optional plugin dependencies:
  • Which Key

📦 Installation

Install the plugin with your preferred package manager, such as Lazy:

{
  "gregorias/coerce.nvim",
  tag = 'v4.1.0',
  config = true,
}

Abolish setup

This plugin effectively replaces Abolish’s coercion functionality. If you wish to keep it for its other features, you can disable the coercion feature like so:

{
  "tpope/vim-abolish",
  init = function()
    -- Disable coercion mappings. I use coerce.nvim for that.
    vim.g.abolish_no_mappings = true
  end,
}

🚀 Usage

You can use Coerce to coerce words into various cases using modes.

• A case is a function that changes a word into another word, e.g., the word’s camel case version.
• A mode specifies how Coerce triggers, selects and transforms the word, e.g., select whatever is currently visually selected.

Quick start

1. Put the cursor inside a keyword.
2. Press crX, where X stands for your desired case. Which key, if present, will show you hints.

Built-in cases

Case	Key
camelCase	c
dot.case	d
kebab-case	k
n12e	n
PascalCase	p
snake_case	s
UPPER_CASE	u
path/case	/
space case	<space>

Built-in modes

Vim mode	Keymap prefix	Selector	Transformer
Normal	cr	current word	LSP rename/local
Normal	gcr	motion selection	local
Visual	gcr	visual selection	local

The default visual prefix is gcr and not cr in order to avoid a conflict with the default c.

Tips & tricks

Visually selecting a previously changed keyword

You may coerce a keyword in such a way that it stops being keyword, e.g., you use the path case in most programming languages. In that case, just running cr again won’t fully revert the case. You’ll need to visually select the word to fix it.

To quickly select a changed keyword, you can configure a special keymap for doing that. For example, here’s how I have it set up:

require"which-key".register({
  g = {
    p = {
      -- "p" makes sense, gv selects the last Visual selection, so this one
      -- selects the last pasted text.
      function()
          vim.api.nvim_feedkeys("`[" .. vim.fn.strpart(vim.fn.getregtype(), 0, 1) .. "`]", "n", false)
      end,
      "Switch to VISUAL using last paste/change",
    },
  },
})

With that, I can use gp to select whatever I have just coerced.

⚙️ Configuration

Setup

The default configuration looks like so:

require"coerce".setup{
  keymap_registry = require("coerce.keymap").keymap_registry(),
  -- The notification function used during error conditions.
  notify = function(...) return vim.notify(...) end,
  default_mode_keymap_prefixes = {
    normal_mode = "cr",
    motion_mode = "gcr",
    visual_mode = "gcr",
  },
  -- Set any field to false to disable that mode.
  default_mode_mask = {
    normal_mode = true,
    motion_mode = true,
    visual_mode = true,
  },
  -- If you don’t like the default cases and modes, you can override them.
  cases = require"coerce".default_cases,
  modes = require"coerce".get_default_modes(default_mode_mask, default_mode_keymap_prefixes),
}

You may freely modify the config parameters to your liking.

Register a new case

You can register a new case like so:

require"coerce".register_case{
  keymap = "l",
  case = function(str)
    return vim.fn.tolower(str)
  end,
  description = "lowercase",
}

Register a new mode

You can register a new mode like so:

require"coerce".register_mode{
  vim_mode = "v",
  keymap_prefix = "gc",
  selector = function(cb)
    local s, e = -- Your function that finds start and end points.
                 -- For example, returning {0, 0}, {0, 5} selects the first 6
                 -- characters of the current buffer.
    local region_m = require"coerce.region"
    cb(region_m(region_m.modes.INLINE, s, e))
  end,
  transformer = require"coerce.transformer".transform_local,
}

Examples

Selectively disabling LSP rename

If you don’t like that the default normal mode binding uses LSP rename (e.g., because it’s too slow), you can provide your own implementation like so:

require"coerce".setup{
  -- …
  default_mode_mask = {
    -- Disable the default `cr` binding.
    normal_mode = false,
  },
  -- …
}

-- Register a custom `cr` binding that uses the local-only transformation.
require"coerce".register_mode{
  vim_mode = "n",
  keymap_prefix = "cr",
  selector = require"coerce.selector".select_current_word,
  transformer = require"coerce.transformer".transform_local,
}

✅ Comparison to similar tools

Text-case is more feature-rich than Coerce, but if you just need to change case of the current keyword, Coerce is simpler.

Feature	Coerce	Text-case	Abolish
Full Unicode support	✅	❌	❌
Which Key integration	✅	✅	❌
nvim-notify integration	✅	❌	❌
Current keyword coerce	✅	❌	✅
Visual selection	✅	✅	❌
Motion selection	✅	✅	❌
LSP rename	✅	✅	❌
Kebab case	✅	✅	✅
Numeronym “case”	✅	❌	❌
Dot repeat support	✅	✅	✅
Custom case support	✅	❌	❌
Custom mode support	✅	❌	❌

🙏 Acknowledgments

This plugin was inspired by Abolish’s coercion feature. I created this plugin to address Abolish’s shortcomings, which are:

• No integration with Which Key or Legendary.
• Little configurability. I couldn’t extend the plugin with new cases.

I used Text-case’s source code to inform myself on how to do things in Neovim.

The logo is based on a fist SVG from SVG Repo.

🔗 See also

• Coop — My Neovim plugin for structured concurrency with coroutines.
• Toggle — My Neovim plugin for toggling options.