New GNU ELPA package: jinx - Enchanted Just-in-time Spell Checker

[Sacha Chua]

    Summary: Enchanted Just-in-time Spell Checker
   Requires: emacs-27.1, compat-29.1.4.0
    Website: https://github.com/minad/jinx
 Maintainer: Daniel Mendler <mail@daniel-mendler.de>
     Author: Daniel Mendler <mail@daniel-mendler.de>
Other versions: 0.4 (gnu).

Jinx provides just-in-time spell-checking via libenchant
(https://abiword.github.io/enchant/).  The package aims to achieve
high performance and low resource usage, without impacting your
editing experience.  Overall Jinx should just work out of the box
without much intervention.

Jinx highlights misspellings lazily only in the visible part of the
text.  The window boundaries and text folding are taken into
account.  Jinx binds directly to the native libenchant API, such
that process communication with a backend Aspell process can be
avoided.  Libenchant is widely used as spell-checking API by text
editors and supports Nuspell, Hunspell, Aspell and a few lesser
known backends.  Jinx automatically compiles and loads the native
module at startup.  Libenchant must be installed on your system for
compilation.  If `pkg-config' is available it will be used to
locate libenchant.  On Debian or Ubuntu, install the packages
`libenchant-2-2', `libenchant-2-dev' and `pkg-config'.

Jinx supports multiple languages in a buffer at the same time via
the `jinx-languages' customization variable.  It offers flexible
settings to ignore misspellings via faces (`jinx-exclude-faces' and
`jinx-include-faces'), regular expressions (`jinx-exclude-regexps')
and programmable predicates.  Jinx comes preconfigured for the most
important major modes.

Jinx offers three auto-loaded entry points , the modes
`global-jinx-mode', `jinx-mode' and the command `jinx-correct'.
You can either enable `global-jinx-mode' or add `jinx-mode' to the
hooks of the modes.

(add-hook 'emacs-startup-hook #'global-jinx-mode)

(dolist (hook '(text-mode-hook prog-mode-hook conf-mode-hook))
  (add-hook hook #'jinx-mode))

In order to correct misspellings bind `jinx-correct' to a
convenient key in your configuration.  Jinx is independent of the
Ispell package, so you can reuse the binding M-$ which is bound to
`ispell-word' by default.  When pressing M-$, Jinx offers
correction suggestions for the misspelling next to point.  If the
prefix key C-u is pressed, the entire buffer is spell-checked.

(keymap-global-set "<remap> <ispell-word>" #'jinx-correct)

Jinx offers a similar UI as Augusto Stoffel's jit-spell package and
borrows ideas from it.  Jit-spell uses Ispell process communication
instead of a native API.  It does not restrict the highlighting to
the visible text.  In my setup I observed an increase in load and
latency as a consequence, in particular in combination with stealth
locking and commands which trigger fontification eagerly like
`consult-line' from my Consult package.

The technique to spell-check only the visible text was inspired by
Campbell Barton's spell-fu package.  Spell-fu maintains the
dictionary itself via a hash table, which results in high memory
usage for languages with compound words or inflected word forms.
In Jinx we avoid the complexity of managing the dictionary and
access the advanced spell-checker algorithms directly via
libenchant (affixation, compound words, etc.).