selectrum: add icon support

Use the package `all-the-icons-completion` to add icons to vertical
completion buffers.

docs/modules.org

@@ -46,7 +46,7 @@ completion.
 + helm =+fuzzy +childframe= - *Another* search engine for love and life
 + ido - The /other/ *other* search engine for love and life
 + [[file:../modules/completion/ivy/README.org][ivy]] =+fuzzy +prescient +childframe +icons= - /The/ search engine for love and life
-+ [[file:../modules/completion/selectrum/README.org][selectrum]] =+prescient= - The search engine of the future
++ [[file:../modules/completion/selectrum/README.org][selectrum]] =+prescient +icons= - The search engine of the future
 
 * :config
 Modules that configure Emacs one way or another, or focus on making it easier

modules/completion/selectrum/README.org

@@ -26,6 +26,7 @@ TODO
 ** Module Flags
 + ~+prescient~ Enables prescient filtering and sorting for Selectrum searches
   instead of orderless.
++ ~+icons~ Adds icons to ~file~ and ~buffer~ category completion selections.
 
 ** Plugins
 [[https://github.com/minad/vertico][vertico]] (~+vertico~, experimental for the moment)
@@ -38,6 +39,7 @@ TODO
 [[https://github.com/mhayashi1120/Emacs-wgrep][wgrep]]
 [[https://github.com/raxod502/prescient.el][prescient]] (~+prescient~)
 [[https://github.com/minad/consult/][consult-flycheck]] (~:checkers syntax~)
+[[https://github.com/iyefrat/all-the-icons-completion][all-the-icons-completion]] (~+icons~)
 
 * Prerequisites
 This module has no prerequisites.

modules/completion/selectrum/TODO.org

@@ -92,6 +92,12 @@ and [[https://github.com/raxod502/selectrum/issues/561][561]], as well as having
   than the bugginess imo.
 *** Vertico is more actively maintained
 This might be a temporary concern, but still.
+** TODO Icon support
+The icon support works well enough when using Vertico, but is a bit dodgy on
+Selectrum due to it not handling lines of varying height that well, which ends
+up causing the selection to slide off the screen when moving it the to the
+bottom in some cases. Hopefully we just use Vertico and this becomes a nonissue,
+but it should still be taken into account.
 
 * PROJ HACKs to be addressed
 ** TODO ~fboundp~ issues
@@ -113,9 +119,6 @@ The clicking links exported grep buffers used to open in a new window, but now
 *** TODO Open upstream Embark issue for ~bookmark~ and ~file~
 ~bookmark~ or ~file~ export buffers open the links in the same window rather than
 the other one. This can be reproduces on emacs -Q.
-** TODO Icons
-Partially solved, seems to have interaction with selectrum height issue, so not
-yet implemented.
 ** TODO ~company~ completions get ordered really weirdly
 This is due to orderless adding a bunch of other matches.
 

modules/completion/selectrum/config.el

@@ -158,6 +158,9 @@
 (use-package! marginalia
   :hook (doom-first-input . marginalia-mode)
   :init
+  (when (featurep! +icons)
+    (add-hook 'marginalia-mode-hook
+              (lambda () (all-the-icons-completion-mode (if marginalia-mode 1 -1)))))
   (map! :map minibuffer-local-map
         :desc "Cycle marginalia views"
         "M-A" #'marginalia-cycle)

modules/completion/selectrum/packages.el

@@ -21,3 +21,8 @@
 (package! marginalia :pin "e31e03c5857bf7aada333f693caedfc3087d6297")
 
 (package! wgrep :pin "f9687c28bbc2e84f87a479b6ce04407bb97cfb23")
+
+(when (featurep! +icons)
+  (package! all-the-icons-completion
+    :recipe (:host github :repo "iyefrat/all-the-icons-completion")
+    :pin "975345f1b618fd316729c3cae6d11b96db530fd4"))