boon/README.md

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Boon: An Ergonomic Command Mode for Emacs
==========================================

Boon is a complete package for modal editing, which is not Evil.

Selling points:
- Ergonomic: common commands are easy to type. (See below)
- Lightweight: ~300 loc for its core.
- Good Emacs integration: integrates well with existing Emacs
  infrastructure and takes advantage of it.


Ergonomic Design
----------------

It is largely accepted that modal edition is more ergonomic than using
key-chords.  Boon attempts to make modal editing as comfortable as
possible, by adhering to the following design principles:

- Spacial allocation first, mnemonics second: the allocation of keys
  to commands is primarily based on the locations of keys on the
  keyboard. Whatever is printed on the key cap is a secondary concern.

- Easy finger rolls: common key combinations should either be
  left/right hand alternation or easy one-hand rolls.

- Use of home row and strong fingers for the most used commands

- Easy navigation: many commands are bound to navigation. This
  allocation of keys facilitates moving around, which is the most
  common task when editting text. Because movements double up as
  region-definitions, this design also makes manipulation commands
  more powerful.

- Prefer an easy two-keystroke combination to a single hard-to-reach
  key. Hard-to-reach keys are free for the user to bind to rarely used
  commands (often user and mode-dependenent).

In command mode, movement keys are bound to the right hand, while text
manipulation is bound to the left hand.


Right-hand.

The leftwards (and upwards) movements are bound to the leftmost
fingers (index and middle finger), while rightwards (and downwards)
movements are bound to the rightmost fingers (ring finger and pinky.)
Additional unpaired, movements are bound to the middle column
(extended reach with index).

Left-hand.

The most common edition commands (cut, paste, parenthesis
manipulation) are bound to the home row. The top row is (mainly) for
searching. The bottom row gives access to regular Emacs stuff (C-x
...) (C-c ...), insert mode, and registers.


Emacs Integration: Reusable Modules
-----------------------------------

Boon is designed as a stack of layers. Each layer is customizable and
provides reusable components, in full agreement with the Emacs
spirit. This means that even if you disagree with the design choices
explained above, you may still want to use some parts of Boon. The
structure of Boon is as follows:

1. boon-moves.el and boon-search.el provide a set of move and search
   commands. These work the same way as standard Emacs commands ---
   they are merely (sometimes) more powerful. Frontends typically bind
   these commands (and more) in boon-moves-map, which is active in
   'command mode'.
2. boon-arguments.el provides a set of selectors to define
   regions. (These selectors are the equivalent of vim 'text
   objects'.) Selectors include plain regions (words, lines,
   paragraphs, ...), but also region transformers (think: exclude
   borders, just borders, including spaces, foreach,
   etc.). Additionally every move command in the boon-moves-map keymap
   can be used as a selector. The selectors are regular interactive
   functions, which means that they are easily customized. On top of
   it all, the system supports multiple-cursors (multiple regions will
   be returned when multiple cursors are active).
3. boon-core.el provides an infrastructure for modal editing. The
   implementation is very much inspired from evil-core, but heavily
   simplified.
4. boon-main.el provides a set of commands. These are similar to
   standard Emacs commands, but they use the system of selectors
   described above. (For good measure, some random extra commands are
   thrown in.) These commands may be used in combination with a modal
   system or not. A few commands also switch to insert mode.
5. boon-keys.el, boon-colemak.el, boon-qwerty.el are frontends. Those
   require all the above and provide a mapping of moves, selectors and
   commands onto keys.

Installation
------------

REQUIREMENTS
- Emacs version >= 24.5
- Qwerty or Colemak layout (workman version partially implemented).

Install Boon (perhaps using
[![MELPA](http://stable.melpa.org/packages/boon-badge.svg)](http://stable.melpa.org/#/boon)),
and add the following to your configuration:

    (require 'boon-colemak)
    ;; (require 'boon-qwerty) ;; for qwerty port (alpha quality)
        (require 'boon-powerline)
    (boon-powerline-theme) ;; if you want use powerline with Boon

Then

    (boon-mode) ;; to enable boon everywhere

If you just eval'ed the above (or just did not want to enable boon
everywhere), Boon may not be active in the current buffer. If it is
not activated and you want to try it locally, activate it by

    M-x turn-on-boon-mode

Usage
-----

You can jump-start by reading the
[cheat sheet](https://pdf.yt/d/hSKUThNNSxrNFXkQ) directly, but reading
through the tutorial is highly recommended:

    M-x boon-tutorial

(You'll get the version of the tutorial adapted to the frontend you
have activated, qwerty or colemak.)

Configuration
-------------

The main variables to configure are:

- boon-select-map, boon-moves-map, boon-command-map. Those are keymaps.
- boon-enclosures, which can be customized.

Comparison with other modal layers for Emacs
---------------------------------------------

- Evil

  Evil is a (quite) complete vi emulation layer for Emacs.

  In Boon, quite a bit of Emacs structure and user experience is
  retained. Examples: the x key gives the C-x prefix map.  The usual
  Emacs (interactive) arguments are used for text objects. Thus most of
  Boon remains usable even if one does not wish to use modal editing.

  Besides, Emacs is already customizable enough as it is: the core of
  Boon is just 300 lines or so. Figuring out all the ins and outs of
  Evil to do what I want would probably have required more effort than
  implementing Boon.

  Finally, evil use vi bindings (by default at least), which do not
  feature the best ergonomics.

- Xah Fly Keys http://ergoemacs.org/misc/ergoemacs_vi_mode.html

  Like boon, Xah Fly Keys aims at providing a layout whose design is
  ergonomic. As far as I understand it follows the spirit of Xah's
  ErgoEmacs package. As I understand it ErgoEmacs makes most design
  decisions differently from boon. I have not made an in-depth
  comparison of ergonomics yet.

- Fingers https://github.com/fgeller/fingers.el

  Fingers borrows a few ideas from Boon, including the division of
  work between left and right hand. fgeller gives a detailed account
  of the particular differences with Boon. My opinion is that Fingers
  is compatible with Boon concepts and could (and probably should) be
  implemented as a Boon 'frontend'.

- God-mode https://github.com/chrisdone/god-mode

  God-mode is similar to "sticky modifier keys" in principle. Its
  simplicity allows to quickly get up to speed with it. However, it
  lacks the main benefit of a true modal layer: text operators. (what
  vi fans call a "language for text edition").

- Modal Mode http://retroj.net/modal-mode

  Another modal layer for Emacs, which is also lightweight and aims to
  integrate with Emacs. However, as far as I can see, there is no
  special attention paid to ergonomics.

- Modal Emacs https://github.com/joelmccracken/modal-emacs

  Modal Emacs does not appear to be complete.