@@ -360,6 +360,26 @@ The Perfect Setup
@code{origin} snippet in turn may insert other trigger strings ending on
@code{...}, which also can be expanded further.
+@cindex skeleton
+If you use built-in skeleton system (@xref{Top,,,autotype}), you can
+load the snippets from the @file{etc/snippets/skeleton} directory.
+
+Skeletons for editing commit messages are provided in
+@file{etc/snippets/skeleton/commit-message.el}.
+
+@cindex @code{M-x guix-package-add}
+@cindex @code{M-x guix-package-remove}
+@cindex @code{M-x guix-package-update}
+@cindex @code{M-x guix-package-rename}
+@cindex @code{M-x guix-package-move}
+Once you load the file, the following functions are provided:
+@code{guix-package-add}, @code{guix-package-remove},
+@code{guix-package-update}, @code{guix-package-rename} and
+@code{guix-package-move}. When editing a commit message, invoke the
+appropriate one using @code{M-x} to insert a message for the change.
+
+The commit message skeletons depend on @url{https://magit.vc/, Magit}.
+
@cindex insert or update copyright
@cindex @code{M-x guix-copyright}
@cindex @code{M-x copyright-update}
new file mode 100644
@@ -0,0 +1,143 @@
+;;; commit-message.el --- skeletons for Guix's commit messages -*- lexical-binding: t; -*-
+;;; Copyright © 2024 Tomas Volf <~@wolfsden.cz>
+
+;; Author: Tomas Volf <~@wolfsden.cz>
+;; Keywords: vc, convenience
+
+;; This program is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+;;; Code:
+
+(defun guix--package-name-from-magit-diff (regex)
+ (with-temp-buffer
+ (magit-git-wash #'magit-diff-wash-diffs "diff" "--cached")
+ (goto-char (point-min))
+ (when (re-search-forward regex
+ nil 'noerror)
+ (match-string-no-properties 1))))
+
+(defun guix--first-file-from-magit-diff ()
+ (car (magit-staged-files)))
+
+(define-skeleton guix-package-add
+ "Insert a commit message for adding a package."
+ nil
+ '(setq v1 (or (guix--package-name-from-magit-diff
+ (rx "+(define-public " (group (+ (not (syntax whitespace))))))
+ (skeleton-read "Package: ")))
+ '(setq v2 (or (guix--first-file-from-magit-diff)
+ (skeleton-read "File: ")))
+ ;; v1 - package, v2 - file
+ "gnu: Add " v1 "." \n
+ _ \n
+ "* " v2 " (" v1 "): New variable." \n)
+
+(define-skeleton guix-package-remove
+ "Insert a commit message for removing a package."
+ nil
+ '(setq v1 (or (guix--package-name-from-magit-diff
+ (rx "-(define-public " (group (+ (not (syntax whitespace))))))
+ (skeleton-read "Package: ")))
+ '(setq v2 (or (guix--first-file-from-magit-diff)
+ (skeleton-read "File: ")))
+ ;; v1 - package, v2 - file
+ "gnu: Remove " v1 "." \n
+ _ \n
+ "* " v2 " (" v1 "): Delete variable." \n)
+
+(define-skeleton guix-package-update
+ "Insert a commit message for updating a package."
+ (or (guix--package-name-from-magit-diff
+ (rx line-start (* (syntax whitespace))
+ "(define-public " (group (+ (not (syntax whitespace))))))
+ (skeleton-read "Package: "))
+ '(setq v1 (or (with-temp-buffer
+ (magit-git-wash #'magit-diff-wash-diffs
+ "diff" "--cached")
+ (goto-char (point-min))
+ (search-forward "name" nil 'noerror)
+ (search-forward "+" nil 'noerror) ; first change
+ (when (and (search-forward "version " nil 'noerror)
+ (looking-at-p "\""))
+ (let ((end (save-excursion (search-forward "\")"
+ nil 'noerror))))
+ (when end
+ (forward-char)
+ (buffer-substring-no-properties (point) (- end 2))))))
+ (skeleton-read "New version: ")))
+ '(setq v2 (or (guix--first-file-from-magit-diff)
+ (skeleton-read "File: ")))
+ ;; str - package, v1 - new version, v2 - file
+ "gnu: " str ": Update to " v1 "." \n
+ _ \n
+ "* " v2 " (" str "): Update to " v1 "." \n)
+
+(define-skeleton guix-package-rename
+ "Insert a commit message for renaming a package."
+ (or (guix--first-file-from-magit-diff)
+ (skeleton-read "File: "))
+ '(setq v1 (or (guix--package-name-from-magit-diff
+ (rx "-(define-public " (group (+ (not (syntax whitespace))))))
+ (skeleton-read "Old package: ")))
+ '(setq v2 (or (guix--package-name-from-magit-diff
+ (rx "+(define-public " (group (+ (not (syntax whitespace))))))
+ (skeleton-read "New package: ")))
+ ;; str - file, v1 - old package, v2 - new package
+ "gnu: " v1 ": Rename package to " v2 "." \n
+ _ \n
+ @
+ "* " str " (" v1 "): Define in terms of `deprecated-package'." \n
+ "(" v2 "): New variable, formerly known as `crawl'." \n
+ @
+ '(fill-region (cadr skeleton-positions) (car skeleton-positions)))
+
+(define-skeleton guix-package-move
+ "Insert a commit message for moving a package."
+ (or (guix--package-name-from-magit-diff
+ (rx "-(define-public " (group (+ (not (syntax whitespace))))))
+ (skeleton-read "Package: "))
+ '(setq v1 (or (with-temp-buffer
+ (magit-git-wash #'magit-diff-wash-diffs
+ "diff" "--cached" "--no-prefix")
+ (goto-char (point-min))
+ (when (and
+ (re-search-forward "\\-(define-public \\(\\S-+\\)"
+ nil 'noerror)
+ (re-search-backward "modified[ ]*\\(\\S-+\\)"
+ nil 'noerror))
+ (match-string-no-properties 1)))
+ (skeleton-read "Old file: ")))
+ '(setq v2 (or (with-temp-buffer
+ (magit-git-wash #'magit-diff-wash-diffs
+ "diff" "--cached" "--no-prefix")
+ (goto-char (point-min))
+ (when (and
+ (re-search-forward "\\+(define-public \\(\\S-+\\)"
+ nil 'noerror)
+ (re-search-backward "modified[ ]*\\(\\S-+\\)"
+ nil 'noerror))
+ (match-string-no-properties 1)))
+ (skeleton-read "New file: ")))
+ ;; str - package, v1 - old file, v2 - new file
+ "gnu: " str ": Move to ("
+ (string-replace ".scm" "" (string-replace "/" " " v2))
+ ")." \n
+ _ \n
+ @
+ "* " v1 " (" str "): Move from here..." \n
+ "* " v2 " (" str "): ...to here." \n
+ @
+ '(fill-region (cadr skeleton-positions) (car skeleton-positions)))
+
+;;; commit-message.el ends here