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Diffstat (limited to 'emacs/guix-prettify.el')
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diff --git a/emacs/guix-prettify.el b/emacs/guix-prettify.el new file mode 100644 index 0000000000..b01495c86b --- /dev/null +++ b/emacs/guix-prettify.el @@ -0,0 +1,204 @@ +;;; guix-prettify.el --- Prettify Guix store file names + +;; Copyright © 2014 Alex Kost <alezost@gmail.com> + +;; This file is part of GNU Guix. + +;; GNU Guix 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. + +;; GNU Guix 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 <http://www.gnu.org/licenses/>. + +;;; Commentary: + +;; This package provides minor-mode for prettifying Guix store file +;; names — i.e., after enabling `guix-prettify-mode', +;; '/gnu/store/72f54nfp6g1hz873w8z3gfcah0h4nl9p-foo-0.1' names will be +;; replaced with '/gnu/store/…-foo-0.1' in the current buffer. There is +;; also `global-guix-prettify-mode' for global prettifying. + +;; To install, add the following to your emacs init file: +;; +;; (add-to-list 'load-path "/path/to/dir-with-guix-prettify") +;; (autoload 'guix-prettify-mode "guix-prettify" nil t) +;; (autoload 'global-guix-prettify-mode "guix-prettify" nil t) + +;; If you want to enable/disable composition after "M-x font-lock-mode", +;; use the following setting: +;; +;; (setq font-lock-extra-managed-props +;; (cons 'composition font-lock-extra-managed-props)) + +;; Credits: +;; +;; Thanks to Ludovic Courtès for the idea of this package. +;; +;; Thanks to the authors of `prettify-symbols-mode' (part of Emacs 24.4) +;; and "pretty-symbols.el" <http://github.com/drothlis/pretty-symbols> +;; for the code. It helped to write this package. + +;;; Code: + +(defgroup guix-prettify nil + "Prettify Guix store file names." + :prefix "guix-prettify-" + :group 'font-lock + :group 'convenience) + +(defcustom guix-prettify-char ?… + "Character used for prettifying." + :type 'character + :group 'guix-prettify) + +(defcustom guix-prettify-decompose-force nil + "If non-nil, remove any composition. + +By default, after disabling `guix-prettify-mode', +compositions (prettifying names with `guix-prettify-char') are +removed only from strings matching `guix-prettify-regexp', so +that compositions created by other modes are left untouched. + +Set this variable to non-nil, if you want to remove any +composition unconditionally (like `prettify-symbols-mode' does). +Most likely it will do no harm and will make the process of +disabling `guix-prettify-mode' a little faster." + :type 'boolean + :group 'guix-prettify) + +(defcustom guix-prettify-regexp + (rx "/" + (or "nix" "gnu") + "/store/" + ;; Hash-parts do not include "e", "o", "u" and "t". See base32Chars + ;; at <https://github.com/NixOS/nix/blob/master/src/libutil/hash.cc> + (group (= 32 (any "0-9" "a-d" "f-n" "p-s" "v-z")))) + "Regexp matching file names for prettifying. + +Disable `guix-prettify-mode' before modifying this variable and +make sure to modify `guix-prettify-regexp-group' if needed. + +Example of a \"deeper\" prettifying: + + (setq guix-prettify-regexp \"store/[[:alnum:]]\\\\\\={32\\\\}\" + guix-prettify-regexp-group 0) + +This will transform +'/gnu/store/72f54nfp6g1hz873w8z3gfcah0h4nl9p-foo-0.1' into +'/gnu/…-foo-0.1'" + :type 'regexp + :group 'guix-prettify) + +(defcustom guix-prettify-regexp-group 1 + "Regexp group in `guix-prettify-regexp' for prettifying." + :type 'integer + :group 'guix-prettify) + +(defvar guix-prettify-special-modes + '(guix-info-mode ibuffer-mode) + "List of special modes that support font-locking. + +By default, \\[global-guix-prettify-mode] enables prettifying in +all buffers except the ones where `font-lock-defaults' is +nil (see Info node `(elisp) Font Lock Basics'), because it may +break the existing highlighting. + +Modes from this list and all derived modes are exceptions +\(`global-guix-prettify-mode' enables prettifying there).") + +(defvar guix-prettify-flush-function + (cond ((fboundp 'font-lock-flush) #'font-lock-flush) + ((fboundp 'jit-lock-refontify) #'jit-lock-refontify)) + "Function used to refontify buffer. +This function is called without arguments after +enabling/disabling `guix-prettify-mode'. If nil, do nothing.") + +(defun guix-prettify-compose () + "Compose matching region in the current buffer." + (let ((beg (match-beginning guix-prettify-regexp-group)) + (end (match-end guix-prettify-regexp-group))) + (compose-region beg end guix-prettify-char 'decompose-region)) + ;; Return nil because we're not adding any face property. + nil) + +(defun guix-prettify-decompose-buffer () + "Remove file names compositions from the current buffer." + (with-silent-modifications + (let ((inhibit-read-only t)) + (if guix-prettify-decompose-force + (remove-text-properties (point-min) + (point-max) + '(composition nil)) + (save-excursion + (goto-char (point-min)) + (while (re-search-forward guix-prettify-regexp nil t) + (remove-text-properties + (match-beginning guix-prettify-regexp-group) + (match-end guix-prettify-regexp-group) + '(composition nil)))))))) + +;;;###autoload +(define-minor-mode guix-prettify-mode + "Toggle Guix Prettify mode. + +With a prefix argument ARG, enable Guix Prettify mode if ARG is +positive, and disable it otherwise. If called from Lisp, enable +the mode if ARG is omitted or nil. + +When Guix Prettify mode is enabled, hash-parts of the Guix store +file names (see `guix-prettify-regexp') are prettified, +i.e. displayed as `guix-prettify-char' character. This mode can +be enabled programmatically using hooks: + + (add-hook 'shell-mode-hook 'guix-prettify-mode) + +It is possible to enable the mode in any buffer, however not any +buffer's highlighting may survive after adding new elements to +`font-lock-keywords' (see `guix-prettify-special-modes' for +details). + +Also you can use `global-guix-prettify-mode' to enable Guix +Prettify mode for all modes that support font-locking." + :init-value nil + :lighter " …" + (let ((keywords `((,guix-prettify-regexp + (,guix-prettify-regexp-group + (guix-prettify-compose)))))) + (if guix-prettify-mode + ;; Turn on. + (font-lock-add-keywords nil keywords) + ;; Turn off. + (font-lock-remove-keywords nil keywords) + (guix-prettify-decompose-buffer)) + (and guix-prettify-flush-function + (funcall guix-prettify-flush-function)))) + +(defun guix-prettify-supported-p () + "Return non-nil, if the mode can be harmlessly enabled in current buffer." + (or font-lock-defaults + (apply #'derived-mode-p guix-prettify-special-modes))) + +(defun guix-prettify-turn-on () + "Enable `guix-prettify-mode' in the current buffer if needed. +See `guix-prettify-special-modes' for details." + (and (not guix-prettify-mode) + (guix-prettify-supported-p) + (guix-prettify-mode))) + +;;;###autoload +(define-globalized-minor-mode global-guix-prettify-mode + guix-prettify-mode guix-prettify-turn-on) + +;;;###autoload +(defalias 'guix-prettify-global-mode 'global-guix-prettify-mode) + +(provide 'guix-prettify) + +;;; guix-prettify.el ends here |