From 3aec865add2b9af7ab7f730a9f3ec5f0fad078ff Mon Sep 17 00:00:00 2001
From: Jakub Czajka <jakub@ekhem.eu.org>
Date: Fri, 23 Dec 2022 19:01:17 +0100
Subject: [PATCH] [emacs] Extend the default minibuffer.

Minibuffer is a special window for selecting from a set of
values (e.g. a file to open). This commit extends the default emacs
minibuffer with orderless (narrowing the set of values) and
vertico (live preview of the set of values).
---
 conf/home/emacs.scm                         | 10 ++++
 emacs/.config/emacs/conf/conf-minibuffer.el | 61 +++++++++++++++++++++
 2 files changed, 71 insertions(+)
 create mode 100644 emacs/.config/emacs/conf/conf-minibuffer.el

diff --git a/conf/home/emacs.scm b/conf/home/emacs.scm
index 2868db1..875c43d 100644
--- a/conf/home/emacs.scm
+++ b/conf/home/emacs.scm
@@ -110,6 +110,15 @@
 	    (dotfiles
 	     (list "emacs/.config/emacs/conf/conf-language.el")))))
 
+(define emacs-minibuffer-service
+  (service home-program-service-type
+	   (home-program-configuration
+	    (packages
+	     (list emacs-orderless
+		   emacs-vertico))
+	    (dotfiles
+	     (list "emacs/.config/emacs/conf/conf-minibuffer.el")))))
+
 (define emacs-package-service
   (service home-program-service-type
 	   (home-program-configuration
@@ -154,6 +163,7 @@
         emacs-email-service
         emacs-keys-service
         emacs-language-service
+        emacs-minibuffer-service
         emacs-package-service
         emacs-pass-service
         emacs-service))
diff --git a/emacs/.config/emacs/conf/conf-minibuffer.el b/emacs/.config/emacs/conf/conf-minibuffer.el
new file mode 100644
index 0000000..3e61cb5
--- /dev/null
+++ b/emacs/.config/emacs/conf/conf-minibuffer.el
@@ -0,0 +1,61 @@
+;; Copyright (c) 2022 Jakub Czajka <jakub@ekhem.eu.org>
+;; License: GPL-3.0 or later.
+;;
+;; conf-minibuffer.el - configuration for the minibuffer.
+
+(require 'conf-package)
+
+;; Use y-or-n instead of yes-or-no.
+(fset 'yes-or-no-p 'y-or-n-p)
+
+(use-package minibuffer
+  ;; Allow to enter a minibuffer while in a minibuffer.
+  :custom
+  (enable-recursive-minibuffers t)
+  :custom-face
+  (minibuffer-prompt ((t :foreground "#fed065"))))
+
+(use-package orderless
+  :ensure t
+  :custom
+  ;; Interpret all input patterns as regular expressions by default.
+  (orderless-matching-styles '(orderless-regexp))
+  ;; Dispatchers for literal and without-literal matching styles.
+  (orderless-style-dispatchers '(with-literal-string without-literal-string))
+  ;; `basic' completion style as fallback.
+  (completion-styles '(orderless basic))
+  (completion-category-defaults nil)
+  ;; `partial-completion' completion style for file name completion.
+  (completion-category-overrides '((file (styles partial-completion))))
+  :config
+  (defun with-literal-string (pattern _index _total)
+    "Orderless dispatcher for literal matching style."
+    (when (string-suffix-p "=" pattern)
+      `(orderless-literal . ,(substring pattern 0 -1))))
+
+  (defun without-literal-string (pattern _index _total)
+    "Orderless dispatcher for without-literal matching style."
+    (when (string-suffix-p "!" pattern)
+      `(orderless-without-literal . ,(substring pattern 0 -1)))))
+
+(use-package vertico
+  :ensure t
+  :init
+  ;; Enable on startup.
+  ;; `vertico-mode' is an autoload.
+  (vertico-mode)
+  :custom
+  ;; Grow or shrink the minibuffer when possible.
+  (vertico-resize t)
+  ;; Hide the count of completion candidates
+  (vertico-count-format '())
+  ;; Make the completion list cyclical.
+  (vertico-cycle t))
+
+(use-package vertico-reverse
+  :init
+  ;; Enable on startup.
+  ;; `vertico-reverse-mode' is an autoload.
+  (vertico-reverse-mode))
+
+(provide 'conf-minibuffer)
-- 
2.39.5