multiple-cursors-core.el

;;; multiple-cursors-core.el --- An experiment in multiple cursors for emacs.

;; Copyright (C) 2012-2016 Magnar Sveen

;; Author: Magnar Sveen <magnars@gmail.com>
;; Keywords: editing cursors

;; 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 <http://www.gnu.org/licenses/>.

;;; Commentary:

;; This file contains the core functionality of multiple-cursors.
;; Please see multiple-cursors.el for more commentary.

;;; Code:

(require 'cl-lib)
(require 'rect)

(defvar mc--read-char)

(defface mc/cursor-face
  '((t (:inverse-video t)))
  "The face used for fake cursors"
  :group 'multiple-cursors)

(defface mc/cursor-bar-face
  `((t (:height 1 :background ,(face-attribute 'cursor :background))))
  "The face used for fake cursors if the cursor-type is bar"
  :group 'multiple-cursors)

(defface mc/region-face
  '((t :inherit region))
  "The face used for fake regions"
  :group 'multiple-cursors)

(defmacro mc/add-fake-cursor-to-undo-list (&rest forms)
  "Make sure point is in the right place when undoing"
  (let ((uc (make-symbol "undo-cleaner")))
    `(let ((,uc (cons 'apply (cons 'deactivate-cursor-after-undo (list id)))))
       (setq buffer-undo-list (cons ,uc buffer-undo-list))
       ,@forms
       (if (eq ,uc (car buffer-undo-list)) ;; if nothing has been added to the undo-list
           (setq buffer-undo-list (cdr buffer-undo-list)) ;; then pop the cleaner right off again
         (setq buffer-undo-list ;; otherwise add a function to activate this cursor
               (cons (cons 'apply (cons 'activate-cursor-for-undo (list id))) buffer-undo-list))))))

(defun mc/all-fake-cursors (&optional start end)
  (cl-remove-if-not 'mc/fake-cursor-p
                    (overlays-in (or start (point-min))
                                 (or end   (point-max)))))

(defmacro mc/for-each-fake-cursor (&rest forms)
  "Runs the body for each fake cursor, bound to the name cursor"
  `(mapc #'(lambda (cursor) ,@forms)
         (mc/all-fake-cursors)))

(defmacro mc/save-excursion (&rest forms)
  "Saves and restores all the state that multiple-cursors cares about."
  (let ((cs (make-symbol "current-state")))
    `(let ((,cs (mc/store-current-state-in-overlay
                 (make-overlay (point) (point) nil nil t))))
       (overlay-put ,cs 'type 'original-cursor)
       (save-excursion ,@forms)
       (mc/pop-state-from-overlay ,cs))))

(defun mc--compare-by-overlay-start (o1 o2)
  (< (overlay-start o1) (overlay-start o2)))

(defmacro mc/for-each-cursor-ordered (&rest forms)
  "Runs the body for each cursor, fake and real, bound to the name cursor"
  (let ((rci (make-symbol "real-cursor-id")))
    `(let ((,rci (overlay-get (mc/create-fake-cursor-at-point) 'mc-id)))
       (mapc #'(lambda (cursor)
                 (when (mc/fake-cursor-p cursor)
                   ,@forms))
             (sort (overlays-in (point-min) (point-max)) 'mc--compare-by-overlay-start))
       (mc/pop-state-from-overlay (mc/cursor-with-id ,rci)))))

(defmacro mc/save-window-scroll (&rest forms)
  "Saves and restores the window scroll position"
  (let ((p (make-symbol "p"))
        (s (make-symbol "start"))
        (h (make-symbol "hscroll")))
    `(let ((,p (set-marker (make-marker) (point)))
           (,s (set-marker (make-marker) (window-start)))
           (,h (window-hscroll)))
       ,@forms
       (goto-char ,p)
       (set-window-start nil ,s t)
       (set-window-hscroll nil ,h)
       (set-marker ,p nil)
       (set-marker ,s nil))))

(defun mc/cursor-is-bar ()
  "Return non-nil if the cursor is a bar."
  (or (eq cursor-type 'bar)
    (and (listp cursor-type)
         (eq (car cursor-type) 'bar))))

(defun mc/line-number-at-pos (&optional pos absolute)
  "Faster implementation of `line-number-at-pos'."
  (if pos
      (save-excursion
        (if absolute
            (save-restriction
              (widen)
              (goto-char pos)
              (string-to-number (format-mode-line "%l")))
          (goto-char pos)
          (string-to-number (format-mode-line "%l"))))
    (string-to-number (format-mode-line "%l"))))

(defun mc/make-cursor-overlay-at-eol (pos)
  "Create overlay to look like cursor at end of line."
  (let ((overlay (make-overlay pos pos nil nil nil)))
    (if (mc/cursor-is-bar)
	(overlay-put overlay 'before-string (propertize "|" 'face 'mc/cursor-bar-face))
      (overlay-put overlay 'after-string (propertize " " 'face 'mc/cursor-face)))
    overlay))

(defun mc/make-cursor-overlay-inline (pos)
  "Create overlay to look like cursor inside text."
  (let ((overlay (make-overlay pos (1+ pos) nil nil nil)))
    (if (mc/cursor-is-bar)
	(overlay-put overlay 'before-string (propertize "|" 'face 'mc/cursor-bar-face))
      (overlay-put overlay 'face 'mc/cursor-face))
    overlay))

(defun mc/make-cursor-overlay-at-point ()
  "Create overlay to look like cursor.
Special case for end of line, because overlay over a newline
highlights the entire width of the window."
  (if (eolp)
      (mc/make-cursor-overlay-at-eol (point))
    (mc/make-cursor-overlay-inline (point))))

(defun mc/make-region-overlay-between-point-and-mark ()
  "Create overlay to look like active region."
  (let ((overlay (make-overlay (mark) (point) nil nil t)))
    (overlay-put overlay 'face 'mc/region-face)
    (overlay-put overlay 'type 'additional-region)
    overlay))

(defvar mc/cursor-specific-vars '(transient-mark-mode
                                  kill-ring
                                  kill-ring-yank-pointer
                                  mark-ring
                                  mark-active
                                  yank-undo-function
                                  autopair-action
                                  autopair-wrap-action
                                  temporary-goal-column
                                  er/history
                                  dabbrev--abbrev-char-regexp
                                  dabbrev--check-other-buffers
                                  dabbrev--friend-buffer-list
                                  dabbrev--last-abbrev-location
                                  dabbrev--last-abbreviation
                                  dabbrev--last-buffer
                                  dabbrev--last-buffer-found
                                  dabbrev--last-direction
                                  dabbrev--last-expansion
                                  dabbrev--last-expansion-location
                                  dabbrev--last-table)
  "A list of vars that need to be tracked on a per-cursor basis.")

(defun mc/store-current-state-in-overlay (o)
  "Store relevant info about point and mark in the given overlay."
  (overlay-put o 'point (set-marker (make-marker) (point)))
  (overlay-put o 'mark (set-marker (make-marker)
				   (let ((mark-even-if-inactive t))
				     (mark))))
  (dolist (var mc/cursor-specific-vars)
    (when (boundp var) (overlay-put o var (symbol-value var))))
  o)

(defun mc/restore-state-from-overlay (o)
  "Restore point and mark from stored info in the given overlay."
  (goto-char (overlay-get o 'point))
  (set-marker (mark-marker) (overlay-get o 'mark))
  (dolist (var mc/cursor-specific-vars)
    (when (boundp var) (set var (overlay-get o var)))))

(defun mc/remove-fake-cursor (o)
  "Delete overlay with state, including dependent overlays and markers."
  (set-marker (overlay-get o 'point) nil)
  (set-marker (overlay-get o 'mark) nil)
  (mc/delete-region-overlay o)
  (delete-overlay o))

(defun mc/pop-state-from-overlay (o)
  "Restore the state stored in given overlay and then remove the overlay."
  (mc/restore-state-from-overlay o)
  (mc/remove-fake-cursor o))

(defun mc/delete-region-overlay (o)
  "Remove the dependent region overlay for a given cursor overlay."
  (ignore-errors
    (delete-overlay (overlay-get o 'region-overlay))))

(defvar mc--current-cursor-id 0
  "Var to store increasing id of fake cursors, used to keep track of them for undo.")

(defun mc/create-cursor-id ()
  "Returns a unique cursor id"
  (cl-incf mc--current-cursor-id))

(defvar mc--max-cursors-original nil
  "This variable maintains the original maximum number of cursors.
When `mc/create-fake-cursor-at-point' is called and
`mc/max-cursors' is overridden, this value serves as a backup so
that `mc/max-cursors' can take on a new value.  When
`mc/remove-fake-cursors' is called, the values are reset.")

(defcustom mc/max-cursors nil
  "Safety ceiling for the number of active cursors.
If your emacs slows down or freezes when using too many cursors,
customize this value appropriately.

Cursors will be added until this value is reached, at which point
you can either temporarily override the value or abort the
operation entirely.

If this value is nil, there is no ceiling."
  :type '(integer)
  :group 'multiple-cursors)

(defun mc/create-fake-cursor-at-point (&optional id)
  "Add a fake cursor and possibly a fake active region overlay based on point and mark.
Saves the current state in the overlay to be restored later."
  (unless mc--max-cursors-original
    (setq mc--max-cursors-original mc/max-cursors))
  (when mc/max-cursors
    (unless (< (mc/num-cursors) mc/max-cursors)
      (if (yes-or-no-p (format "%d active cursors. Continue? " (mc/num-cursors)))
          (setq mc/max-cursors (read-number "Enter a new, temporary maximum: "))
        (mc/remove-fake-cursors)
        (error "Aborted: too many cursors"))))
  (let ((overlay (mc/make-cursor-overlay-at-point)))
    (overlay-put overlay 'mc-id (or id (mc/create-cursor-id)))
    (overlay-put overlay 'type 'fake-cursor)
    (overlay-put overlay 'priority 100)
    (mc/store-current-state-in-overlay overlay)
    (when (use-region-p)
      (overlay-put overlay 'region-overlay
                   (mc/make-region-overlay-between-point-and-mark)))
    overlay))

(defun mc/execute-command (cmd)
  "Run command, simulating the parts of the command loop that makes sense for fake cursors."
  (setq this-command cmd)
  (run-hooks 'pre-command-hook)
  (unless (eq this-command 'ignore)
    (call-interactively cmd))
  (run-hooks 'post-command-hook)
  (when deactivate-mark (deactivate-mark)))

(defvar mc--executing-command-for-fake-cursor nil)

(defun mc/execute-command-for-fake-cursor (cmd cursor)
  (let ((mc--executing-command-for-fake-cursor t)
        (id (overlay-get cursor 'mc-id))
        (annoying-arrows-mode nil)
        (smooth-scroll-margin 0))
    (mc/add-fake-cursor-to-undo-list
     (mc/pop-state-from-overlay cursor)
     (ignore-errors
       (mc/execute-command cmd)
       (mc/create-fake-cursor-at-point id)))))

(defun mc/execute-command-for-all-fake-cursors (cmd)
  "Calls CMD interactively for each cursor.
It works by moving point to the fake cursor, setting
up the proper environment, and then removing the cursor.
After executing the command, it sets up a new fake
cursor with updated info."
  (mc/save-excursion
   (mc/save-window-scroll
    (mc/for-each-fake-cursor
     (save-excursion
       (mc/execute-command-for-fake-cursor cmd cursor)))))
  (mc--reset-read-prompts))

(defun mc/execute-command-for-all-cursors (cmd)
  "Calls CMD interactively for the real cursor and all fakes."
  (call-interactively cmd)
  (mc/execute-command-for-all-fake-cursors cmd))

;; Intercept some reading commands so you won't have to
;; answer them for every single cursor

(defvar mc--read-char nil)
(defvar multiple-cursors-mode nil)
(defadvice read-char (around mc-support activate)
  (if (not multiple-cursors-mode)
      ad-do-it
    (unless mc--read-char
      (setq mc--read-char ad-do-it))
    (setq ad-return-value mc--read-char)))

(defvar mc--read-quoted-char nil)
(defadvice read-quoted-char (around mc-support activate)
  (if (not multiple-cursors-mode)
      ad-do-it
    (unless mc--read-quoted-char
      (setq mc--read-quoted-char ad-do-it))
    (setq ad-return-value mc--read-quoted-char)))

(defun mc--reset-read-prompts ()
  (setq mc--read-char nil)
  (setq mc--read-quoted-char nil))

(mc--reset-read-prompts)

(defun mc/fake-cursor-p (o)
  "Predicate to check if an overlay is a fake cursor"
  (eq (overlay-get o 'type) 'fake-cursor))

(defun mc/cursor-with-id (id)
  "Find the first cursor with the given id, or nil"
  (cl-find-if #'(lambda (o) (and (mc/fake-cursor-p o)
                            (= id (overlay-get o 'mc-id))))
              (overlays-in (point-min) (point-max))))

(defvar mc--stored-state-for-undo nil
  "Variable to keep the state of the real cursor while undoing a fake one")

(defun activate-cursor-for-undo (id)
  "Called when undoing to temporarily activate the fake cursor which action is being undone."
  (let ((cursor (mc/cursor-with-id id)))
    (when cursor
      (setq mc--stored-state-for-undo (mc/store-current-state-in-overlay
                                       (make-overlay (point) (point) nil nil t)))
      (mc/pop-state-from-overlay cursor))))

(defun deactivate-cursor-after-undo (id)
  "Called when undoing to reinstate the real cursor after undoing a fake one."
  (when mc--stored-state-for-undo
    (mc/create-fake-cursor-at-point id)
    (mc/pop-state-from-overlay mc--stored-state-for-undo)
    (setq mc--stored-state-for-undo nil)))

(defcustom mc/always-run-for-all nil
  "Disables whitelisting and always executes commands for every fake cursor."
  :type '(boolean)
  :group 'multiple-cursors)

(defcustom mc/always-repeat-command nil
  "Disables confirmation for `mc/repeat-command' command."
  :type '(boolean)
  :group 'multiple-cursors)

(defun mc/prompt-for-inclusion-in-whitelist (original-command)
  "Asks the user, then adds the command either to the once-list or the all-list."
  (let ((all-p (y-or-n-p (format "Do %S for all cursors?" original-command))))
    (if all-p
        (add-to-list 'mc/cmds-to-run-for-all original-command)
      (add-to-list 'mc/cmds-to-run-once original-command))
    (mc/save-lists)
    all-p))

(defun mc/num-cursors ()
  "The number of cursors (real and fake) in the buffer."
  (1+ (cl-count-if 'mc/fake-cursor-p
                   (overlays-in (point-min) (point-max)))))

(defvar mc--this-command nil
  "Used to store the original command being run.")
(make-variable-buffer-local 'mc--this-command)

(defun mc/make-a-note-of-the-command-being-run ()
  "Used with pre-command-hook to store the original command being run.
Since that cannot be reliably determined in the post-command-hook.

Specifically, this-original-command isn't always right, because it could have
been remapped. And certain modes (cua comes to mind) will change their
remapping based on state. So a command that changes the state will afterwards
not be recognized through the command-remapping lookup."
  (unless mc--executing-command-for-fake-cursor
    (let ((cmd (or (command-remapping this-original-command)
                   this-original-command)))
      (setq mc--this-command (and (not (eq cmd 'god-mode-self-insert))
                                  cmd)))))

(defun mc/execute-this-command-for-all-cursors ()
  "Wrap around `mc/execute-this-command-for-all-cursors-1' to protect hook."
  (condition-case error
      (mc/execute-this-command-for-all-cursors-1)
    (error
     (message "[mc] problem in `mc/execute-this-command-for-all-cursors': %s"
              (error-message-string error)))))

;; execute-kbd-macro should never be run for fake cursors. The real cursor will
;; execute the keyboard macro, resulting in new commands in the command loop,
;; and the fake cursors can pick up on those instead.
(defadvice execute-kbd-macro (around skip-fake-cursors activate)
  (unless mc--executing-command-for-fake-cursor
    ad-do-it))

(defun mc/execute-this-command-for-all-cursors-1 ()
  "Used with post-command-hook to execute supported commands for all cursors.

It uses two lists of commands to know what to do: the run-once
list and the run-for-all list. If a command is in neither of these lists,
it will prompt for the proper action and then save that preference.

Some commands are so unsupported that they are even prevented for
the original cursor, to inform about the lack of support."
  (unless mc--executing-command-for-fake-cursor

    (if (eq 1 (mc/num-cursors)) ;; no fake cursors? disable mc-mode
        (multiple-cursors-mode 0)
      (when this-original-command
        (let ((original-command (or mc--this-command
                                    (command-remapping this-original-command)
                                    this-original-command)))

          ;; skip keyboard macros, since they will generate actual commands that are
          ;; also run in the command loop - we'll handle those later instead.
          (when (functionp original-command)

            ;; if it's a lambda, we can't know if it's supported or not
            ;; - so go ahead and assume it's ok, because we're just optimistic like that
            (if (or (not (symbolp original-command))
                    ;; lambda registered by smartrep
                    (string-prefix-p "(" (symbol-name original-command)))
                (mc/execute-command-for-all-fake-cursors original-command)

              ;; smartrep `intern's commands into own obarray to help
              ;; `describe-bindings'.  So, let's re-`intern' here to
              ;; make the command comparable by `eq'.
              (setq original-command (intern (symbol-name original-command)))

              ;; otherwise it's a symbol, and we can be more thorough
              (if (get original-command 'mc--unsupported)
                  (message "%S is not supported with multiple cursors%s"
                           original-command
                           (get original-command 'mc--unsupported))

                ;; lazy-load the user's list file
                (mc/load-lists)

                (when (and original-command
                           (not (memq original-command mc--default-cmds-to-run-once))
                           (not (memq original-command mc/cmds-to-run-once))
                           (or mc/always-run-for-all
                               (memq original-command mc--default-cmds-to-run-for-all)
                               (memq original-command mc/cmds-to-run-for-all)
                               (mc/prompt-for-inclusion-in-whitelist original-command)))
                  (mc/execute-command-for-all-fake-cursors original-command))))))))))

(defun mc/remove-fake-cursors ()
  "Remove all fake cursors.
Do not use to conclude editing with multiple cursors. For that
you should disable multiple-cursors-mode."
  (mc/for-each-fake-cursor
   (mc/remove-fake-cursor cursor))
  (when mc--max-cursors-original
    (setq mc/max-cursors mc--max-cursors-original))
  (setq mc--max-cursors-original nil))

(defun mc/keyboard-quit ()
  "Deactivate mark if there are any active, otherwise exit multiple-cursors-mode."
  (interactive)
  (if (not (use-region-p))
      (multiple-cursors-mode 0)
    (deactivate-mark)))

(defun mc/repeat-command ()
  "Run last command from `command-history' for every fake cursor."
  (interactive)
  (when (or mc/always-repeat-command
            (y-or-n-p (format "[mc] repeat complex command: %s? " (caar command-history))))
    (mc/execute-command-for-all-fake-cursors
     (lambda () (interactive)
       (cl-letf (((symbol-function 'read-from-minibuffer)
                  (lambda (p &optional i k r h d m) (read i))))
         (repeat-complex-command 0))))))

(defvar mc/keymap nil
  "Keymap while multiple cursors are active.
Main goal of the keymap is to rebind C-g and <return> to conclude
multiple cursors editing.")
(unless mc/keymap
  (setq mc/keymap (make-sparse-keymap))
  (define-key mc/keymap (kbd "C-g") 'mc/keyboard-quit)
  (define-key mc/keymap (kbd "<return>") 'multiple-cursors-mode)
  (define-key mc/keymap (kbd "C-:") 'mc/repeat-command)
  (when (fboundp 'phi-search)
    (define-key mc/keymap (kbd "C-s") 'phi-search))
  (when (fboundp 'phi-search-backward)
    (define-key mc/keymap (kbd "C-r") 'phi-search-backward)))

(defun mc--all-equal (list)
  "Are all the items in LIST equal?"
  (let ((first (car list))
        (all-equal t))
    (while (and all-equal list)
      (setq all-equal (equal first (car list)))
      (setq list (cdr list)))
    all-equal))

(defun mc--kill-ring-entries ()
  "Return the latest kill-ring entry for each cursor.
The entries are returned in the order they are found in the buffer."
  (let (entries)
    (mc/for-each-cursor-ordered
     (setq entries (cons (car (overlay-get cursor 'kill-ring)) entries)))
    (reverse entries)))

(defun mc--maybe-set-killed-rectangle ()
  "Add the latest kill-ring entry for each cursor to killed-rectangle.
So you can paste it in later with `yank-rectangle'."
  (let ((entries (let (mc/max-cursors) (mc--kill-ring-entries))))
    (unless (mc--all-equal entries)
      (setq killed-rectangle entries))))

(defvar mc/unsupported-minor-modes '(company-mode auto-complete-mode flyspell-mode jedi-mode)
  "List of minor-modes that does not play well with multiple-cursors.
They are temporarily disabled when multiple-cursors are active.")

(defvar mc/temporarily-disabled-minor-modes nil
  "The list of temporarily disabled minor-modes.")
(make-variable-buffer-local 'mc/temporarily-disabled-minor-modes)

(defun mc/temporarily-disable-minor-mode (mode)
  "If MODE is available and turned on, remember that and turn it off."
  (when (and (boundp mode) (eval mode))
    (add-to-list 'mc/temporarily-disabled-minor-modes mode)
    (funcall mode -1)))

(defun mc/temporarily-disable-unsupported-minor-modes ()
  (mapc 'mc/temporarily-disable-minor-mode mc/unsupported-minor-modes))

(defun mc/enable-minor-mode (mode)
  (funcall mode 1))

(defun mc/enable-temporarily-disabled-minor-modes ()
  (mapc 'mc/enable-minor-mode mc/temporarily-disabled-minor-modes)
  (setq mc/temporarily-disabled-minor-modes nil))

(defcustom mc/mode-line
  `(" mc:" (:eval (format ,(propertize "%d" 'face 'font-lock-warning-face)
                          (mc/num-cursors))))
  "What to display in the mode line while multiple-cursors-mode is active."
  :group 'multiple-cursors)
(put 'mc/mode-line 'risky-local-variable t)

;;;###autoload
(define-minor-mode multiple-cursors-mode
  "Mode while multiple cursors are active."
  nil mc/mode-line mc/keymap
  (if multiple-cursors-mode
      (progn
        (mc/temporarily-disable-unsupported-minor-modes)
        (add-hook 'pre-command-hook 'mc/make-a-note-of-the-command-being-run nil t)
        (add-hook 'post-command-hook 'mc/execute-this-command-for-all-cursors t t)
        (run-hooks 'multiple-cursors-mode-enabled-hook))
    (remove-hook 'post-command-hook 'mc/execute-this-command-for-all-cursors t)
    (remove-hook 'pre-command-hook 'mc/make-a-note-of-the-command-being-run t)
    (setq mc--this-command nil)
    (mc--maybe-set-killed-rectangle)
    (mc/remove-fake-cursors)
    (mc/enable-temporarily-disabled-minor-modes)
    (run-hooks 'multiple-cursors-mode-disabled-hook)))

(add-hook 'after-revert-hook #'(lambda () (multiple-cursors-mode 0)))

(defun mc/maybe-multiple-cursors-mode ()
  "Enable multiple-cursors-mode if there is more than one currently active cursor."
  (if (> (mc/num-cursors) 1)
      (multiple-cursors-mode 1)
    (multiple-cursors-mode 0)))

(defmacro unsupported-cmd (cmd msg)
  "Adds command to list of unsupported commands and prevents it
from being executed if in multiple-cursors-mode."
  `(progn
     (put (quote ,cmd) 'mc--unsupported ,msg)
     (defadvice ,cmd (around unsupported-advice activate)
       "command isn't supported with multiple cursors"
       (unless (and multiple-cursors-mode (called-interactively-p 'any))
         ad-do-it))))

;; Commands that does not work with multiple-cursors
(unsupported-cmd isearch-forward ". Feel free to add a compatible version.")
(unsupported-cmd isearch-backward ". Feel free to add a compatible version.")

;; Make sure pastes from other programs are added to all kill-rings when yanking
(defadvice current-kill (before interprogram-paste-for-all-cursors
				(n &optional do-not-move) activate)
  (let ((interprogram-paste (and (= n 0)
                                 interprogram-paste-function
                                 (funcall interprogram-paste-function))))
    (when interprogram-paste
      ;; Add interprogram-paste to normal kill ring, just
      ;; like current-kill usually does for itself.
      ;; We have to do the work for it tho, since the funcall only returns
      ;; something once. It is not a pure function.
      (let ((interprogram-cut-function nil))
        (if (listp interprogram-paste)
            (mapc 'kill-new (nreverse interprogram-paste))
          (kill-new interprogram-paste))
        ;; And then add interprogram-paste to the kill-rings
        ;; of all the other cursors too.
        (mc/for-each-fake-cursor
         (let ((kill-ring (overlay-get cursor 'kill-ring))
               (kill-ring-yank-pointer (overlay-get cursor 'kill-ring-yank-pointer)))
           (if (listp interprogram-paste)
               (mapc 'kill-new (nreverse interprogram-paste))
             (kill-new interprogram-paste))
           (overlay-put cursor 'kill-ring kill-ring)
           (overlay-put cursor 'kill-ring-yank-pointer kill-ring-yank-pointer)))))))

(defcustom mc/list-file (locate-user-emacs-file ".mc-lists.el")
  "The position of the file that keeps track of your preferences
for running commands with multiple cursors."
  :type 'file
  :group 'multiple-cursors)

(defvar mc--list-file-loaded nil
  "Whether the list file has already been loaded.")

(defun mc/load-lists ()
  "Loads preferences for running commands with multiple cursors from `mc/list-file'"
  (unless mc--list-file-loaded
    (load mc/list-file 'noerror 'nomessage)
    (setq mc--list-file-loaded t)))

(defun mc/dump-list (list-symbol)
  "Insert (setq 'LIST-SYMBOL LIST-VALUE) to current buffer."
  (cl-symbol-macrolet ((value (symbol-value list-symbol)))
    (insert "(setq " (symbol-name list-symbol) "\n"
            "      '(")
    (newline-and-indent)
    (set list-symbol
         (sort value (lambda (x y) (string-lessp (symbol-name x)
                                            (symbol-name y)))))
    (mapc #'(lambda (cmd) (insert (format "%S" cmd)) (newline-and-indent))
          value)
    (insert "))")
    (newline)))

(defun mc/save-lists ()
  "Saves preferences for running commands with multiple cursors to `mc/list-file'"
  (with-temp-file mc/list-file
    (emacs-lisp-mode)
    (insert ";; This file is automatically generated by the multiple-cursors extension.")
    (newline)
    (insert ";; It keeps track of your preferences for running commands with multiple cursors.")
    (newline)
    (newline)
    (mc/dump-list 'mc/cmds-to-run-for-all)
    (newline)
    (mc/dump-list 'mc/cmds-to-run-once)))

(defvar mc/cmds-to-run-once nil
  "Commands to run only once in multiple-cursors-mode.")

(defvar mc--default-cmds-to-run-once nil
  "Default set of commands to run only once in multiple-cursors-mode.")

(setq mc--default-cmds-to-run-once '(mc/edit-lines
                                     mc/edit-ends-of-lines
                                     mc/edit-beginnings-of-lines
                                     mc/mark-next-like-this
				     mc/mark-next-like-this-word
				     mc/mark-next-like-this-symbol
                                     mc/mark-next-word-like-this
                                     mc/mark-next-symbol-like-this
                                     mc/mark-previous-like-this
                                     mc/mark-previous-like-this-word
                                     mc/mark-previous-like-this-symbol
                                     mc/mark-previous-word-like-this
                                     mc/mark-previous-symbol-like-this
                                     mc/mark-all-like-this
                                     mc/mark-all-words-like-this
                                     mc/mark-all-symbols-like-this
                                     mc/mark-more-like-this-extended
                                     mc/mark-all-like-this-in-defun
                                     mc/mark-all-words-like-this-in-defun
                                     mc/mark-all-symbols-like-this-in-defun
                                     mc/mark-all-like-this-dwim
                                     mc/mark-all-dwim
                                     mc/mark-sgml-tag-pair
                                     mc/insert-numbers
				     mc/insert-letters
                                     mc/sort-regions
                                     mc/reverse-regions
                                     mc/cycle-forward
                                     mc/cycle-backward
                                     mc/add-cursor-on-click
                                     mc/mark-pop
                                     mc/add-cursors-to-all-matches
                                     mc/mmlte--left
                                     mc/mmlte--right
                                     mc/mmlte--up
                                     mc/mmlte--down
                                     mc/unmark-next-like-this
                                     mc/unmark-previous-like-this
                                     mc/skip-to-next-like-this
                                     mc/skip-to-previous-like-this
                                     rrm/switch-to-multiple-cursors
                                     mc-hide-unmatched-lines-mode
                                     mc/repeat-command
                                     hum/keyboard-quit
                                     hum/unhide-invisible-overlays
                                     save-buffer
                                     ido-exit-minibuffer
                                     ivy-done
                                     exit-minibuffer
                                     minibuffer-complete-and-exit
                                     execute-extended-command
                                     eval-expression
                                     undo
                                     redo
                                     undo-tree-undo
                                     undo-tree-redo
                                     universal-argument
                                     universal-argument-more
                                     universal-argument-other-key
                                     negative-argument
                                     digit-argument
                                     top-level
                                     recenter-top-bottom
                                     describe-mode
                                     describe-key-1
                                     describe-function
                                     describe-bindings
                                     describe-prefix-bindings
                                     view-echo-area-messages
                                     other-window
                                     kill-buffer-and-window
                                     split-window-right
                                     split-window-below
                                     delete-other-windows
                                     toggle-window-split
                                     mwheel-scroll
                                     scroll-up-command
                                     scroll-down-command
                                     mouse-set-point
                                     mouse-drag-region
                                     quit-window
                                     toggle-read-only
                                     windmove-left
                                     windmove-right
                                     windmove-up
                                     windmove-down
                                     repeat-complex-command))

(defvar mc--default-cmds-to-run-for-all nil
  "Default set of commands that should be mirrored by all cursors")

(setq mc--default-cmds-to-run-for-all '(mc/keyboard-quit
                                        self-insert-command
                                        quoted-insert
                                        previous-line
                                        next-line
                                        newline
                                        newline-and-indent
                                        open-line
                                        delete-blank-lines
                                        transpose-chars
                                        transpose-lines
                                        transpose-paragraphs
                                        transpose-regions
                                        join-line
                                        right-char
                                        right-word
                                        forward-char
                                        forward-word
                                        left-char
                                        left-word
                                        backward-char
                                        backward-word
                                        forward-paragraph
                                        backward-paragraph
                                        upcase-word
                                        downcase-word
                                        capitalize-word
                                        forward-list
                                        backward-list
                                        hippie-expand
                                        hippie-expand-lines
                                        yank
                                        yank-pop
                                        append-next-kill
                                        kill-word
                                        kill-line
                                        kill-whole-line
                                        backward-kill-word
                                        backward-delete-char-untabify
                                        delete-char delete-forward-char
                                        delete-backward-char
                                        py-electric-backspace
                                        c-electric-backspace
                                        org-delete-backward-char
                                        cperl-electric-backspace
                                        python-indent-dedent-line-backspace
                                        paredit-backward-delete
                                        autopair-backspace
                                        just-one-space
                                        zap-to-char
                                        end-of-line
                                        set-mark-command
                                        exchange-point-and-mark
                                        cua-set-mark
                                        cua-replace-region
                                        cua-delete-region
                                        move-end-of-line
                                        beginning-of-line
                                        move-beginning-of-line
                                        kill-ring-save
                                        back-to-indentation
                                        subword-forward
                                        subword-backward
                                        subword-mark
                                        subword-kill
                                        subword-backward-kill
                                        subword-transpose
                                        subword-capitalize
                                        subword-upcase
                                        subword-downcase
                                        er/expand-region
                                        er/contract-region
                                        smart-forward
                                        smart-backward
                                        smart-up
                                        smart-down))

(defvar mc/cmds-to-run-for-all nil
  "Commands to run for all cursors in multiple-cursors-mode")

(provide 'multiple-cursors-core)

;; Local Variables:
;; coding: utf-8
;; End:

;;; multiple-cursors-core.el ends here