hjkl.el

Move in emacs using context dependent keybindings.

---

hjkl provides an easy way to navigate source files using context dependent keybindings, ie keybindings that trigger an action depending on characters that follow or precede the point (cursor). The idea is to move swiftly by semantically relevant units in a language agnostic way. You use hjkl-up, hjkl-down and other keybindings to jump to the previous or next semantic unit (a sexp, a paragraph for example) when point is after or behind a regular expression.

In a way, hjkl was born as the result of my frustration not being able to use lispy keybindings in all major modes.

Installation

This module is currently in beta version and not (yet) available on MELPA.

To install use

$ git clone https://github.com/sam217pa/emacs-hjkl

and add the following use-package declaration into your .emacs file:

(use-package hjkl
  :load-path "path/to/emacs-hjkl"
  :config
  (setq hjkl-up (kbd "K")) ; if k does not suits you.
  (hjkl-define-keys ...))

Usage

The following code tells emacs to jump to the next sentence when the cursor is positioned after a period, an exclamation or question mark, or to jump to the next outline heading if the cursor is before the value of outline-regexp, when the key defined by hjkl-down is pressed. Otherwise the key calling hjkl-down acts normally.

(hjkl-define-keys
 '((:keymap text-mode-map
    :bind (:down (("\\.\\|?\\|!" #'forward-sentence back)
                  (outline-regexp #'outline-next-heading))))))

It results into the evaluation of the following snippet:

(define-key text-mode-map hjkl-down
  (lambda () (interactive)
    (cond ((looking-back "\\.\\|?\\|!")
           (funcall #'forward-sentence))
          ((looking-at outline-regexp)
           (outline-next-heading))
          (t (self-insert-command 1)))))

(More information on context-dependent keybindings can be found here.)

hjkl Directions

hjkl provides several keybindings by default, corresponding to hjkl-directions:

• :up: bound to k by default, useful to goes up a semantic unit. It can be used to jump to the beginning of the previous paragraph, SEXP or outline-heading.

• :down: bound to j by default, it makes sense to bind function that does the opposite of those bound to hjkl-up.

• :left or :right: bound to h and l by default, useful to goes out of a semantic unit. It can be used to jump to the enclosing parent delimiter when the cursor is before a closing delimiter, or to hide the body of the current outline heading.

• :jump: bound to a by default, useful to jump to a specific location using avy for example.

• :eval: bound to e by default, used to evaluate SEXP or expression in a REPL. It is useful in emacs-lisp, ESS-modes, python and languages that interact with a REPL.

• :mark: bound to m by default, used to mark expressions, paragraphs and

• stuff like that.

• :other: bound to o by default, jump to the corresponding delimiter.

Example config

Contributions

I would really appreciate contributions as this is my first package. I am sure it does some really wrong things, and that it can be improved a lot. I'll be glad to have feedbacks on it !

Disclaimer

hjkl still feels a lot like a hack to me, but it does kinda work as I expected, so I felt I would put it in the open. Maybe it will break things in your config, but as the GPL says, it is distributed without any garantee … ;)

Function Documentation

(hjkl-define-keys KEY-DEFINITION)

Call ‘hjkl--define-key’ on each sublist of KEY-DEFINITION.

KEY-DEFINITION should be a list of the form

’((:keymap KEYMAP
   :bind (:DIRECTION ((RE FUNCTION-CALL BACK)))))

:keymap should be a valid emacs keymap.

:bind is mandatory, it corresponds to the list of condition to check for each hjkl direction.

RE is a valid regular expression, passed to ‘looking-at’ if BACK is nil (the default) or ‘looking-back’ if BACK is t.

FUNCTION-CALL can be a simple function call of the form #’function or a lambda expression.

An example usage would be the following snippet:

(hjkl-define-keys
 ’((:keymap text-mode-map
    :bind (:up (("\.\|?\|!" (lambda ()
                                   (backward-sentence)
                                   (backward-char 1))
                 back))
           :down (("\.\|?\|!" #’forward-sentence back))))))

It bind ‘hjkl-up’ to jump to the beginning of the previous sentence when the cursor is after a ‘.‘, a ‘?‘ or a ‘!‘ and ‘hjkl-down’ to go the next sentence. The "back" mention is optional but indicate that the characters that matters precedes the cursor.

(hjkl-update-keys)

Update keybinding definition if ‘‘hjkl-bindings’’ is defined by calling ‘‘hjkl-define-keys’’ on it.

---

Markdown README file generated by make-readme-markdown.el