Dkendal / nvim-minor-mode

Emacs like minor modes for Neovim

Nvim-minor-mode

This package adds similar functionality as Emacs’s minor modes.

Minor modes

Within the definition of this package a minor mode is a set of keymaps that are enabled with some command, and can be disabled using the same command.

They’re useful for functionality that you don’t necessarily always want to be active.

Installation

Use whatever package manager you like:

Plug 'Dkendal/nvim-minor-mode'

use { 'Dkendal/nvim-minor-mode' }

Usage

Minor modes can be defined using the define_minor_mode function.

Say I wanted to defined a “lisp” minor mode. While I could write a new plugin and define it for all filetypes that are a lisp, I could instead define a minor mode and enable it as desired while editing files.

local define_minor_mode = require('minor-mode').define_minor_mode

define_minor_mode('lisp', [[
  Minor modes for lisps to navigate sexps. Replaces some normal movement
  keybindings.
  ]], {
  command = 'LispMode',
  keymap = {
    {
      'n',
      'j',
      function()
        vim.fn.search('(')
      end,
      { silent = true }
    },

    {
      'n',
      'k',
      function()
        vim.fn.search('(', 'b')
      end,
      { silent = true }
    }
  }
})

The second argument, LispMode, will be used to define a new command.

:LispMode

Calling it again will remove all the keymaps.

Types

vim-expr :: string

command-name :: string

  A valid vim command name.

mode :: "n" | "v" | "x" | ... | "!" ""

  See [map-overview] or [nvim_set_keymap]

minor-mode-name :: string

lhs :: string

rhs :: vim-expr | function

  Standard right hand side of a keybinding, but can also be a lua function.

mapping-opts :: {
  nowait = boolean,
  silent = boolean,
  script = boolean,
  expr = boolean,
  unique = boolean,
  noremap = boolean,
}

  See the definition of {opts} for [nvim_set_keymap].

mapping :: { mode lhs, rhs, mapping-opts || null }

  Same arguments as [nvim_set_keymap], except rhs may also be a lua function.

keymap :: { mapping }

API

All top level API functions should treat kebab-case methods and underscore_case functions interchangeably for fennel and lua use, respectively.

define_minor_mode(mode :: minor-mode-name, doc :: string, minor-mode-opts)

Defines a new minor mode whose name is mode (a string). It defines a Vim command named after opts.command to toggle the minor mode, standard Vim command naming rules apply (:h :user-cmd-ambiguous). Provide a short explanation of what the minor mode is in doc-string - this value isn’t exposed anywhere at the moment.

minor-mode-opts is a map, key values are defined below:

:command command-name

:keymap keymap

An array of key bindings that will be activated with the minor mode. Key bindings are the same as arguments to nvim_set_keymap (:h nvim_set_keymap())

Here’s an example keymap:

{
  keymap = {
    { 'n', '<c-p>', ':echo \"down\"', { silent = true } },
    { 'n', '<c-n>', ':echo \"up\"',   { silent = true } } }
  }
}

Caveats

This plugin uses buffer local keymaps, if you already have a buffer local keymap present, or overwrite it with another while a minor mode is active and then disable said minor mode, the keymap will be removed.

Related

• https://github.com/kana/vim-submode
• https://www.gnu.org/software/emacs/manual/html_node/elisp/Defining-Minor-Modes.html

Liscence

MPL-2.0