Emacs's NEWS files are useful as a searchable reference, but they can
be overwhelming as an entry point.  In this file, I'm keeping track of
the changes /I/ am excited about.
* 29
** =:core= promotions
A couple of ELPA packages have moved to emacs.git, making them
available out of the box.
*** eglot ("Emacs Polyglot"): LSP client
Lets Emacs leverage language servers to boost completion-at-point,
eldoc, flymake, imenu, project, xref.
*** use-package: init-file management
A utility macro for configuring packages that makes init-file
management more pleasant (and efficient to boot):

- OT1H, brings some amount of structure and order when compared to a
  fully free-form DYI =.emacs=,
- OTOH, allows more leeway on how to organize things, when compared to
  Custom's rigid auto-generated forms (e.g. using regular code
  comments, computing option values, sorting options arbitrarily),
- takes care of setting up the ~eval-after-load~ wizardry to keep
  startup snappy.

A tedious aspect of porting a ~custom-file~ to ~use-package~
declarations is tracking down what package defines which variables,
since not every variable is named after the package it belongs to.
I wrote [[file:~/memory-leaks/guides/emacs/use-package.org::*Porting from ~custom-file~][some code to make the process faster]].
** ~global-text-scale-adjust~
~text-scale-adjust~ (bound to =C-x C-X= ∀ =X= ∈ =[=+-0]=) only scales
the font size in the current buffer; more often than not, one may want
to increase the default font size everywhere (e.g. when projecting
their screen).

To that end, users had to =M-x customize-face RET default= or =M-:=
~(set-face-attribute 'default nil :height …)~; now they can use the
new =C-x C-M-X= bindings to invoke ~global-text-scale-adjust~.
** ~split-root-window-{below,right}~
E.g. when you already have a vertical split, and you'd like to spawn a
full-height window to the side (instead of splitting either the top or
bottom window horizontally and keeping the other full-width).

Been missing this in both Emacs and Terminator; glad Emacs now has a
solution.

Part of the new window keymap on =C-x w=.
** ~rename-visited-file~
Instead of =C-x C-w NEWNAME RET M-! rm OLDNAME RET=.
** "fold hints" for outlines
~outline-minor-mode-use-buttons~ can be set to either

- =in-margins=: magit-section-like indicators,
- =t=: in-buffer buttons.

Initially the latter used arguably "garish" color emoji; with the
addition of the =icons.el= library, the way these buttons are
displayed can now be controlled with ~icon-preference~, which defaults
to more sober SVG images.
** ~imenu~ now bound to =M-g i=
Turns out that lots of modes define an imenu.
** ~setopt~ sets variables and runs their Custom setters
** "Pure GTK" Emacs
Some brave souls took it upon themselves to drag Emacs kicking and
screaming into The Wayland Future™: "pure GTK" means that Emacs will
only rely on GTK APIs, instead of a mix of GTK and X.

Try it out by giving =--with-pgtk= to =./configure=.  One caveat is
that GTK input methods… eat modifiers or something?  E.g. =S-SPC=
degrades to =SPC=.  Apparently Emacs users are the only ones to care
about that? 🤷

(Note for whoever feels like debugging that: this problem can be
reproduced on the X+GTK build by setting ~x-gtk-use-native-input~)
** Honorable mentions
These have me excited too, but I have nits to pick with the current
incarnation.
*** ~pixel-scroll-precision-mode~
Setting that minor mode with ~pixel-scroll-precision-interpolate-page~
makes =PageUp= and =PageDown= much smoother.  Would love for =M-v= and
=C-v= to use that as well…  Heck, would love for all scrolling,
jumping and recentering commands to use that.
*** Picking completions from the minibuffer
=M-<up>= and =M-<down>= in the minibuffer cycle through completion
candidates.  Would love for these to have non-arrow bindings
(e.g. =C-c C-[pn]= with a repeat map?).

Unsetting ~minibuffer-completion-auto-choose~ also lets the user
choose when to insert candidates in the minibuffer: =C-u M-RET= to
just insert, or =M-RET= to insert and immediately exit the minibuffer.
*** =C-x 8 e= keymap to search & insert emoji
Less hassle than =C-x 8 RET err what was the name again=, especially
for composed emoji 😵‍💫

Uses transient 👍 but relies on auto-generated, non-mnemonic =a-z=
suffixes to pick gender/color variations 👎 rather than taking
advantage of transient prefixes (e.g. =-g= for gender and =-s= for
skin tone), which

1. don't add an unecessary step for the common "ungendered Lego" case,
2. can remember a user's preferred values with ~transient-save~.

Upstream considers this idea "[[https://yhetil.org/emacs-devel/87ilxfx1ku.fsf@gnus.org/][fraught politically]]" 🤷

Others agree it would be [[https://yhetil.org/emacs-devel/87r1bx9pwo.fsf@bernoul.li/][nice-to-have, though not must-have]]; maybe
I'll take a stab at implementing it (making it opt-in, keeping the
alphabetical suffixes by default).
* 28
** Transient input methods
*** Background
Input methods make it easier to type in certain classes of characters.
Emacs includes different kinds of methods:

- alternative keyboard layouts :: if you are familiar with specific
  layouts, e.g. Dvorak, French AZERTY, Russian, you can ask Emacs to
  switch to this layout;

- composition :: some methods let you specify characters by typing in
  short sequences of other symbols:
  - =french-prefix= provides easy access to diacritics with e.g. ='e=
    for =é=, =,c= for =ç=;
  - =TeX= turns TeX macros such as =\alpha=, =\pi=, =\le=, =\ne=,
    =\wedge= into their corresponding characters, i.e. α, π, ≤, ≠, ∧.

Input methods can be toggled with =C-\=; prefix that with =C-u= to
select a new method.  =C-h I <METHOD>= shows what characters
=<METHOD>= supports.  =C-u C-x == on a character tells you how to
input that character with the current input method ("to input: …").
*** What's new
The new =C-x \= command enables an input method temporarily, just for
the next character, and disables it afterward.

As an occasional user of the =TeX= method, I find this useful because
I no longer need to choose between
1. enabling =TeX=, typing a sequence, disabling =TeX=, or
2. enabling =TeX=, typing a sequence, keeping =TeX= enabled, getting
   bitten by it whenever I type in =oh_no= and that turns into =ohₙo=.

=C-x \= seems to follow the same rules as =C-\=:
- the first time you call it, it prompts for a method,
- subsequent calls do not prompt,
- add =C-u= to get a prompt back.
** ~same-window-prefix~, ~other-window-prefix~, ~other-frame-prefix~
The rules which govern how Emacs manages windows are beyond my
reckoning.  I know [[https://protesilaos.com/codelog/2020-01-07-emacs-display-buffer/][it is possible to tame them]] with patience and
discipline; still, these new commands appeal to my humble caveman
brain.

Assuming the command run by key sequence =KEYSEQ= will display its own
buffer =BUF=,

- =C-x 4 1 KEYSEQ= says "please display =BUF= right here, in this
  window";
- =C-x 4 4 KEYSEQ= says "please display =BUF= in another window";
- =C-x 5 5 KEYSEQ= says "please display =BUF= in another frame".

These new ~other-…-prefix~ commands can be seen as generalizations of
specialized shorthands such as =C-x 4 f= or =C-x 5 b=.
** Visibility-cycling with =TAB= in outline.el
=TAB= and =S-TAB= now work in Outline mode like they do in Org.  Look
at e.g. NEWS (=C-h N=) to see them in action.  Customize
~outline-minor-mode-cycle~ to enable this in ~outline-minor-mode~.

One small, /tiny/ step toward chipping good features out of Org in
order to generalize them.
** ~yank-from-kill-ring~
I've always been somewhat ambivalent about Emacs's ~kill-ring~:

1. Everything I ever copied is saved forever!  This is a revolutionary
   feature on par with the undo system 🙌

2. … Surely we can find a more ergonomic UI than =C-y M-y M-y M-y=
   /dammit/ =C-_ C-_= /ah screw it/ =C-h v kill-ring RET C-s= 🤔

And lo!  =M-y= now prompts for the ~kill-ring~ item to yank, with
completion.  This makes the ~kill-ring~ much more accessible IMO.
** ~repeat-mode~
=C-x o o o=!
** ~completions-group~, ~read-char-by-name-sort~
Some very welcome quality-of-life tweaks to =C-x 8 RET=.
** Gnus
*** =#= now toggles the process mark by default
No need for =M-#= anymore.
** Vertical icomplete
*** Settings
- ~completions-detailed~
- ~icomplete-scroll~
- ~icomplete-vertical-mode~
*** Advantages over plain icomplete
- annotations
- completion candidates are easier to tell apart
- =C-n= and =C-p= (=C-.= is awkward on AZERTY)
*** Advantages over Ivy and Vertico
- regular minibuffer bindings work:
  - =SPC= completes
  - =RET= yields current input, disregarding completion candidates
  - =C-j= yields selected completion candidate
- regular icomplete bindings work:
  - =C-M-i= inserts selected completion candidate
** Dired
*** ~dired-kill-when-opening-new-dired-buffer~
With this option, =RET= and =^= no longer make Dired buffers pile up 🎉

Previously, =a= (~dired-find-alternate-file~) could be used instead of
=RET=, but one had to write a custom command for =^=.
** Help
*** Outline in ~describe-bindings~
~describe-bindings-outline~ makes =C-h b='s output less overwhelming.
*** New commands for ~describe-{function,variable}~:
- =c= :: for variables, bring up the *Customize* UI,
- =i= :: bring up the relevant *Info* page,
- =s= :: jump to the *source* definition.
*** ~shortdoc-display-group~
Concise reference docs for specific topics.
** Tabs
For a long time I did not bother to check out the new tab bar, since I
did not expect to find a way to make tabs work in my rather byzantine
buffer management.

Then one day I started playing with the =C-x t= prefix on a whim, and
I was surprised by how much mileage I got out of forking off to a new
tab in order to "tuck away" the current window layout.
* 27
** ~what-cursor-show-names~
I sometimes use =C-u C-x == to (re)discover how the Unicode consortium
decided some character should be called; having plain =C-x == give me
that information without popping an extra buffer is neat.