lisp/register.el

   1 ;;; register.el --- register commands for Emacs
   2
   3 ;; Copyright (C) 1985, 1993-1994, 2001-2013 Free Software Foundation,
   4 ;; Inc.
   5
   6 ;; Maintainer: FSF
   7 ;; Keywords: internal
   8 ;; Package: emacs
   9
  10 ;; This file is part of GNU Emacs.
  11
  12 ;; GNU Emacs is free software: you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation, either version 3 of the License, or
  15 ;; (at your option) any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  24
  25 ;;; Commentary:
  26
  27 ;; This package of functions emulates and somewhat extends the venerable
  28 ;; TECO's `register' feature, which permits you to save various useful
  29 ;; pieces of buffer state to named variables.  The entry points are
  30 ;; documented in the Emacs user's manual.
  31
  32 (eval-when-compile (require 'cl-lib))
  33
  34 ;;; Code:
  35
  36 (cl-defstruct
  37   (registerv (:constructor nil)
  38              (:constructor registerv--make (&optional data print-func
  39                                                       jump-func insert-func))
  40              (:copier nil)
  41              (:type vector)
  42              :named)
  43   (data        nil :read-only t)
  44   (print-func  nil :read-only t)
  45   (jump-func   nil :read-only t)
  46   (insert-func nil :read-only t))
  47
  48 (cl-defun registerv-make (data &key print-func jump-func insert-func)
  49   "Create a register value object.
  50
  51 DATA can be any value.
  52 PRINT-FUNC if provided controls how `list-registers' and
  53 `view-register' print the register.  It should be a function
  54 receiving one argument DATA and print text that completes
  55 this sentence:
  56   Register X contains [TEXT PRINTED BY PRINT-FUNC]
  57 JUMP-FUNC if provided, controls how `jump-to-register' jumps to the register.
  58 INSERT-FUNC if provided, controls how `insert-register' insert the register.
  59 They both receive DATA as argument."
  60   (registerv--make data print-func jump-func insert-func))
  61
  62 (defvar register-alist nil
  63   "Alist of elements (NAME . CONTENTS), one for each Emacs register.
  64 NAME is a character (a number).  CONTENTS is a string, number, marker, list
  65 or a struct returned by `registerv-make'.
  66 A list of strings represents a rectangle.
  67 A list of the form (file . FILE-NAME) represents the file named FILE-NAME.
  68 A list of the form (file-query FILE-NAME POSITION) represents
  69  position POSITION in the file named FILE-NAME, but query before
  70  visiting it.
  71 A list of the form (WINDOW-CONFIGURATION POSITION)
  72  represents a saved window configuration plus a saved value of point.
  73 A list of the form (FRAME-CONFIGURATION POSITION)
  74  represents a saved frame configuration plus a saved value of point.")
  75
  76 (defgroup register nil
  77   "Register commands."
  78   :group 'convenience
  79   :version "24.3")
  80
  81 (defcustom register-separator nil
  82   "Register containing the text to put between collected texts, or nil if none.
  83
  84 When collecting text with
  85 `append-to-register' (resp. `prepend-to-register') contents of
  86 this register is added to the beginning (resp. end) of the marked
  87 text."
  88   :group 'register
  89   :type '(choice (const :tag "None" nil)
  90                  (character :tag "Use register" :value ?+)))
  91
  92 (defun get-register (register)
  93   "Return contents of Emacs register named REGISTER, or nil if none."
  94   (cdr (assq register register-alist)))
  95
  96 (defun set-register (register value)
  97   "Set contents of Emacs register named REGISTER to VALUE.  Returns VALUE.
  98 See the documentation of the variable `register-alist' for possible VALUEs."
  99   (let ((aelt (assq register register-alist)))
 100     (if aelt
 101         (setcdr aelt value)
 102       (push (cons register value) register-alist))
 103     value))
 104
 105 (defun point-to-register (register &optional arg)
 106   "Store current location of point in register REGISTER.
 107 With prefix argument, store current frame configuration.
 108 Use \\[jump-to-register] to go to that location or restore that configuration.
 109 Argument is a character, naming the register."
 110   (interactive "cPoint to register: \nP")
 111   ;; Turn the marker into a file-ref if the buffer is killed.
 112   (add-hook 'kill-buffer-hook 'register-swap-out nil t)
 113   (set-register register
 114                 (if arg (list (current-frame-configuration) (point-marker))
 115                   (point-marker))))
 116
 117 (defun window-configuration-to-register (register &optional _arg)
 118   "Store the window configuration of the selected frame in register REGISTER.
 119 Use \\[jump-to-register] to restore the configuration.
 120 Argument is a character, naming the register."
 121   (interactive "cWindow configuration to register: \nP")
 122   ;; current-window-configuration does not include the value
 123   ;; of point in the current buffer, so record that separately.
 124   (set-register register (list (current-window-configuration) (point-marker))))
 125
 126 (defun frame-configuration-to-register (register &optional _arg)
 127   "Store the window configuration of all frames in register REGISTER.
 128 Use \\[jump-to-register] to restore the configuration.
 129 Argument is a character, naming the register."
 130   (interactive "cFrame configuration to register: \nP")
 131   ;; current-frame-configuration does not include the value
 132   ;; of point in the current buffer, so record that separately.
 133   (set-register register (list (current-frame-configuration) (point-marker))))
 134
 135 (defalias 'register-to-point 'jump-to-register)
 136 (defun jump-to-register (register &optional delete)
 137   "Move point to location stored in a register.
 138 If the register contains a file name, find that file.
 139 \(To put a file name in a register, you must use `set-register'.)
 140 If the register contains a window configuration (one frame) or a frame
 141 configuration (all frames), restore that frame or all frames accordingly.
 142 First argument is a character, naming the register.
 143 Optional second arg non-nil (interactively, prefix argument) says to
 144 delete any existing frames that the frame configuration doesn't mention.
 145 \(Otherwise, these frames are iconified.)"
 146   (interactive "cJump to register: \nP")
 147   (let ((val (get-register register)))
 148     (cond
 149      ((registerv-p val)
 150       (cl-assert (registerv-jump-func val) nil
 151               "Don't know how to jump to register %s"
 152               (single-key-description register))
 153       (funcall (registerv-jump-func val) (registerv-data val)))
 154      ((and (consp val) (frame-configuration-p (car val)))
 155       (set-frame-configuration (car val) (not delete))
 156       (goto-char (cadr val)))
 157      ((and (consp val) (window-configuration-p (car val)))
 158       (set-window-configuration (car val))
 159       (goto-char (cadr val)))
 160      ((markerp val)
 161       (or (marker-buffer val)
 162           (error "That register's buffer no longer exists"))
 163       (switch-to-buffer (marker-buffer val))
 164       (goto-char val))
 165      ((and (consp val) (eq (car val) 'file))
 166       (find-file (cdr val)))
 167      ((and (consp val) (eq (car val) 'file-query))
 168       (or (find-buffer-visiting (nth 1 val))
 169           (y-or-n-p (format "Visit file %s again? " (nth 1 val)))
 170           (error "Register access aborted"))
 171       (find-file (nth 1 val))
 172       (goto-char (nth 2 val)))
 173      (t
 174       (error "Register doesn't contain a buffer position or configuration")))))
 175
 176 (defun register-swap-out ()
 177   "Turn markers into file-query references when a buffer is killed."
 178   (and buffer-file-name
 179        (dolist (elem register-alist)
 180          (and (markerp (cdr elem))
 181               (eq (marker-buffer (cdr elem)) (current-buffer))
 182               (setcdr elem
 183                       (list 'file-query
 184                             buffer-file-name
 185                             (marker-position (cdr elem))))))))
 186
 187 (defun number-to-register (number register)
 188   "Store a number in a register.
 189 Two args, NUMBER and REGISTER (a character, naming the register).
 190 If NUMBER is nil, a decimal number is read from the buffer starting
 191 at point, and point moves to the end of that number.
 192 Interactively, NUMBER is the prefix arg (none means nil)."
 193   (interactive "P\ncNumber to register: ")
 194   (set-register register
 195                 (if number
 196                     (prefix-numeric-value number)
 197                   (if (looking-at "\\s-*-?[0-9]+")
 198                       (progn
 199                         (goto-char (match-end 0))
 200                         (string-to-number (match-string 0)))
 201                     0))))
 202
 203 (defun increment-register (prefix register)
 204   "Augment contents of REGISTER.
 205 Interactively, PREFIX is in raw form.
 206
 207 If REGISTER contains a number, add `prefix-numeric-value' of
 208 PREFIX to it.
 209
 210 If REGISTER is empty or if it contains text, call
 211 `append-to-register' with `delete-flag' set to PREFIX."
 212   (interactive "P\ncIncrement register: ")
 213   (let ((register-val (get-register register)))
 214     (cond
 215      ((numberp register-val)
 216       (let ((number (prefix-numeric-value prefix)))
 217         (set-register register (+ number register-val))))
 218      ((or (not register-val) (stringp register-val))
 219       (append-to-register register (region-beginning) (region-end) prefix))
 220      (t (error "Register does not contain a number or text")))))
 221
 222 (defun view-register (register)
 223   "Display what is contained in register named REGISTER.
 224 The Lisp value REGISTER is a character."
 225   (interactive "cView register: ")
 226   (let ((val (get-register register)))
 227     (if (null val)
 228         (message "Register %s is empty" (single-key-description register))
 229       (with-output-to-temp-buffer "*Output*"
 230         (describe-register-1 register t)))))
 231
 232 (defun list-registers ()
 233   "Display a list of nonempty registers saying briefly what they contain."
 234   (interactive)
 235   (let ((list (copy-sequence register-alist)))
 236     (setq list (sort list (lambda (a b) (< (car a) (car b)))))
 237     (with-output-to-temp-buffer "*Output*"
 238       (dolist (elt list)
 239         (when (get-register (car elt))
 240           (describe-register-1 (car elt))
 241           (terpri))))))
 242
 243 (defun describe-register-1 (register &optional verbose)
 244   (princ "Register ")
 245   (princ (single-key-description register))
 246   (princ " contains ")
 247   (let ((val (get-register register)))
 248     (cond
 249      ((registerv-p val)
 250       (if (registerv-print-func val)
 251           (funcall (registerv-print-func val) (registerv-data val))
 252         (princ "[UNPRINTABLE CONTENTS].")))
 253
 254      ((numberp val)
 255       (princ val))
 256
 257      ((markerp val)
 258       (let ((buf (marker-buffer val)))
 259         (if (null buf)
 260             (princ "a marker in no buffer")
 261           (princ "a buffer position:\n    buffer ")
 262           (princ (buffer-name buf))
 263           (princ ", position ")
 264           (princ (marker-position val)))))
 265
 266      ((and (consp val) (window-configuration-p (car val)))
 267       (princ "a window configuration."))
 268
 269      ((and (consp val) (frame-configuration-p (car val)))
 270       (princ "a frame configuration."))
 271
 272      ((and (consp val) (eq (car val) 'file))
 273       (princ "the file ")
 274       (prin1 (cdr val))
 275       (princ "."))
 276
 277      ((and (consp val) (eq (car val) 'file-query))
 278       (princ "a file-query reference:\n    file ")
 279       (prin1 (car (cdr val)))
 280       (princ ",\n    position ")
 281       (princ (car (cdr (cdr val))))
 282       (princ "."))
 283
 284      ((consp val)
 285       (if verbose
 286           (progn
 287             (princ "the rectangle:\n")
 288             (while val
 289               (princ "    ")
 290               (princ (car val))
 291               (terpri)
 292               (setq val (cdr val))))
 293         (princ "a rectangle starting with ")
 294         (princ (car val))))
 295
 296      ((stringp val)
 297       (if (eq yank-excluded-properties t)
 298           (set-text-properties 0 (length val) nil val)
 299         (remove-list-of-text-properties 0 (length val)
 300                                         yank-excluded-properties val))
 301       (if verbose
 302           (progn
 303             (princ "the text:\n")
 304             (princ val))
 305         (cond
 306          ;; Extract first N characters starting with first non-whitespace.
 307          ((string-match (format "[^ \t\n].\\{,%d\\}"
 308                                 ;; Deduct 6 for the spaces inserted below.
 309                                 (min 20 (max 0 (- (window-width) 6))))
 310                         val)
 311           (princ "text starting with\n    ")
 312           (princ (match-string 0 val)))
 313          ((string-match "^[ \t\n]+$" val)
 314           (princ "whitespace"))
 315          (t
 316           (princ "the empty string")))))
 317      (t
 318       (princ "Garbage:\n")
 319       (if verbose (prin1 val))))))
 320
 321 (defun insert-register (register &optional arg)
 322   "Insert contents of register REGISTER.  (REGISTER is a character.)
 323 Normally puts point before and mark after the inserted text.
 324 If optional second arg is non-nil, puts mark before and point after.
 325 Interactively, second arg is non-nil if prefix arg is supplied."
 326   (interactive "*cInsert register: \nP")
 327   (push-mark)
 328   (let ((val (get-register register)))
 329     (cond
 330      ((registerv-p val)
 331       (cl-assert (registerv-insert-func val) nil
 332               "Don't know how to insert register %s"
 333               (single-key-description register))
 334       (funcall (registerv-insert-func val) (registerv-data val)))
 335      ((consp val)
 336       (insert-rectangle val))
 337      ((stringp val)
 338       (insert-for-yank val))
 339      ((numberp val)
 340       (princ val (current-buffer)))
 341      ((and (markerp val) (marker-position val))
 342       (princ (marker-position val) (current-buffer)))
 343      (t
 344       (error "Register does not contain text"))))
 345   (if (not arg) (exchange-point-and-mark)))
 346
 347 (defun copy-to-register (register start end &optional delete-flag)
 348   "Copy region into register REGISTER.
 349 With prefix arg, delete as well.
 350 Called from program, takes four args: REGISTER, START, END and DELETE-FLAG.
 351 START and END are buffer positions indicating what to copy."
 352   (interactive "cCopy to register: \nr\nP")
 353   (set-register register (filter-buffer-substring start end))
 354   (setq deactivate-mark t)
 355   (cond (delete-flag
 356          (delete-region start end))
 357         ((called-interactively-p 'interactive)
 358          (indicate-copied-region))))
 359
 360 (defun append-to-register (register start end &optional delete-flag)
 361   "Append region to text in register REGISTER.
 362 With prefix arg, delete as well.
 363 Called from program, takes four args: REGISTER, START, END and DELETE-FLAG.
 364 START and END are buffer positions indicating what to append."
 365   (interactive "cAppend to register: \nr\nP")
 366   (let ((reg (get-register register))
 367         (text (filter-buffer-substring start end))
 368         (separator (and register-separator (get-register register-separator))))
 369     (set-register
 370      register (cond ((not reg) text)
 371                     ((stringp reg) (concat reg separator text))
 372                     (t (error "Register does not contain text")))))
 373   (setq deactivate-mark t)
 374   (cond (delete-flag
 375          (delete-region start end))
 376         ((called-interactively-p 'interactive)
 377          (indicate-copied-region))))
 378
 379 (defun prepend-to-register (register start end &optional delete-flag)
 380   "Prepend region to text in register REGISTER.
 381 With prefix arg, delete as well.
 382 Called from program, takes four args: REGISTER, START, END and DELETE-FLAG.
 383 START and END are buffer positions indicating what to prepend."
 384   (interactive "cPrepend to register: \nr\nP")
 385   (let ((reg (get-register register))
 386         (text (filter-buffer-substring start end))
 387         (separator (and register-separator (get-register register-separator))))
 388     (set-register
 389      register (cond ((not reg) text)
 390                     ((stringp reg) (concat text separator reg))
 391                     (t (error "Register does not contain text")))))
 392   (setq deactivate-mark t)
 393   (cond (delete-flag
 394          (delete-region start end))
 395         ((called-interactively-p 'interactive)
 396          (indicate-copied-region))))
 397
 398 (defun copy-rectangle-to-register (register start end &optional delete-flag)
 399   "Copy rectangular region into register REGISTER.
 400 With prefix arg, delete as well.
 401 To insert this register in the buffer, use \\[insert-register].
 402
 403 Called from a program, takes four args: REGISTER, START, END and DELETE-FLAG.
 404 START and END are buffer positions giving two corners of rectangle."
 405   (interactive "cCopy rectangle to register: \nr\nP")
 406   (let ((rectangle (if delete-flag
 407                        (delete-extract-rectangle start end)
 408                      (extract-rectangle start end))))
 409     (set-register register rectangle)
 410     (when (and (null delete-flag)
 411                (called-interactively-p 'interactive))
 412       (setq deactivate-mark t)
 413       (indicate-copied-region (length (car rectangle))))))
 414
 415
 416 (provide 'register)
 417 ;;; register.el ends here