feat(editor): add custom yank-indent package

When yank-indent-mode is enabled, yanked (pasted) text is indented based
on the indent rules of the current major mode. It has a
global-yank-indent-mode too which by default excludes a long list of
known indentation sensitive modes with which this approach does not work
very well.

It is based on some random hacky snippets elisp I've been using for over
a decade. Said snippets are themselves based on some random snippets I
found online, and since morphed into the weird monster they had become.

core/siren-core-custom.el

@@ -12,25 +12,6 @@
   "Basic settings for Siren."
   :group 'tools)
 
-(defcustom siren-yank-indent-threshold 1000
-  "Threshold (# chars) over which indentation does not automatically occur."
-  :type 'number
-  :group 'siren)
-
-(defcustom siren-indent-sensitive-modes
-  '(coffee-mode conf-mode haml-mode makefile-automake-mode makefile-bsdmake-mode
-                makefile-gmake-mode makefile-imake-mode makefile-makepp-mode
-                makefile-mode python-mode slim-mode yaml-mode)
-  "Major modes for which auto-indenting is suppressed."
-  :type '(repeat symbol)
-  :group 'siren)
-
-(defcustom siren-yank-indent-modes '(LaTeX-mode TeX-mode)
-  "Major modes in which to indent regions that are yanked (or yank-popped).
-Only modes that don't derive from `prog-mode' should be listed here."
-  :type '(repeat symbol)
-  :group 'siren)
-
 (defcustom siren-transparency-level 99
   "The default frame transparency level for Emacs frames."
   :type 'number

core/siren-core-editor.el

@@ -95,32 +95,6 @@
 (put 'upcase-region 'disabled nil)
 (put 'downcase-region 'disabled nil)
 
-;; automatically indenting yanked text if in programming-modes
-(defun yank-advised-indent-function (beg end)
-  "Do indentation, as long as the region isn't too large."
-  (if (<= (- end beg) siren-yank-indent-threshold)
-      (indent-region beg end nil)))
-
-(defmacro advise-commands (advice-name commands class &rest body)
-  "Apply advice named ADVICE-NAME to multiple COMMANDS.
-
-The body of the advice is in BODY."
-  `(progn
-     ,@(mapcar (lambda (command)
-                 `(defadvice ,command (,class ,(intern (concat (symbol-name command) "-" advice-name)) activate)
-                    ,@body))
-               commands)))
-
-(advise-commands "indent" (yank yank-pop) after
-  "If current mode is one of `siren-yank-indent-modes',
-indent yanked text (with prefix arg don't indent)."
-  (if (and (not (ad-get-arg 0))
-           (not (member major-mode siren-indent-sensitive-modes))
-           (or (derived-mode-p 'prog-mode)
-               (member major-mode siren-yank-indent-modes)))
-      (let ((transient-mark-mode nil))
-        (yank-advised-indent-function (region-beginning) (region-end)))))
-
 ;; make a shell script executable automatically on save
 (add-hook 'after-save-hook
           'executable-make-buffer-file-executable-if-script-p)

core/siren-core-modules.el

@@ -52,6 +52,7 @@
 (require 'siren-vundo)
 (require 'siren-which-key)
 (require 'siren-whitespace)
+(require 'siren-yank-indent)
 
 ;; Completion Systems and Interfaces
 (require 'siren-vertico)