lisp/register.el

   1 ;;; register.el --- register commands for Emacs
   2
   3 ;; Copyright (C) 1985, 1993-1994, 2001-2012 Free Software Foundation, Inc.
   4
   5 ;; Maintainer: FSF
   6 ;; Keywords: internal
   7 ;; Package: emacs
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software: you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation, either version 3 of the License, or
  14 ;; (at your option) any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  23
  24 ;;; Commentary:
  25
  26 ;; This package of functions emulates and somewhat extends the venerable
  27 ;; TECO's `register' feature, which permits you to save various useful
  28 ;; pieces of buffer state to named variables.  The entry points are
  29 ;; documented in the Emacs user's manual.
  30
  31 (eval-when-compile (require 'cl-lib))
  32
  33 (declare-function semantic-insert-foreign-tag "semantic/tag" (foreign-tag))
  34 (declare-function semantic-tag-buffer "semantic/tag" (tag))
  35 (declare-function semantic-tag-start "semantic/tag" (tag))
  36
  37 ;;; Code:
  38
  39 (cl-defstruct
  40   (registerv (:constructor nil)
  41              (:constructor registerv--make (&optional data print-func
  42                                                       jump-func insert-func))
  43              (:copier nil)
  44              (:type vector)
  45              :named)
  46   (data        nil :read-only t)
  47   (print-func  nil :read-only t)
  48   (jump-func   nil :read-only t)
  49   (insert-func nil :read-only t))
  50
  51 (cl-defun registerv-make (data &key print-func jump-func insert-func)
  52   "Create a register value object.
  53
  54 DATA can be any value.
  55 PRINT-FUNC if provided controls how `list-registers' and
  56 `view-register' print the register.  It should be a function
  57 receiving one argument DATA and print text that completes
  58 this sentence:
  59   Register X contains [TEXT PRINTED BY PRINT-FUNC]
  60 JUMP-FUNC if provided, controls how `jump-to-register' jumps to the register.
  61 INSERT-FUNC if provided, controls how `insert-register' insert the register.
  62 They both receive DATA as argument."
  63   (registerv--make data print-func jump-func insert-func))
  64
  65 (defvar register-alist nil
  66   "Alist of elements (NAME . CONTENTS), one for each Emacs register.
  67 NAME is a character (a number).  CONTENTS is a string, number, marker, list
  68 or a struct returned by `registerv-make'.
  69 A list of strings represents a rectangle.
  70 A list of the form (file . FILE-NAME) represents the file named FILE-NAME.
  71 A list of the form (file-query FILE-NAME POSITION) represents
  72  position POSITION in the file named FILE-NAME, but query before
  73  visiting it.
  74 A list of the form (WINDOW-CONFIGURATION POSITION)
  75  represents a saved window configuration plus a saved value of point.
  76 A list of the form (FRAME-CONFIGURATION POSITION)
  77  represents a saved frame configuration plus a saved value of point.")
  78
  79 (defgroup register nil
  80   "Register commands."
  81   :group 'convenience
  82   :version "24.3")
  83
  84 (defcustom register-separator nil
  85   "Register containing the text to put between collected texts, or nil if none.
  86
  87 When collecting text with
  88 `append-to-register' (resp. `prepend-to-register') contents of
  89 this register is added to the beginning (resp. end) of the marked
  90 text."
  91   :group 'register
  92   :type '(choice (const :tag "None" nil)
  93                  (character :tag "Use register" :value ?+)))
  94
  95 (defun get-register (register)
  96   "Return contents of Emacs register named REGISTER, or nil if none."
  97   (cdr (assq register register-alist)))
  98
  99 (defun set-register (register value)
 100   "Set contents of Emacs register named REGISTER to VALUE.  Returns VALUE.
 101 See the documentation of the variable `register-alist' for possible VALUEs."
 102   (let ((aelt (assq register register-alist)))
 103     (if aelt
 104         (setcdr aelt value)
 105       (push (cons register value) register-alist))
 106     value))
 107
 108 (defun point-to-register (register &optional arg)
 109   "Store current location of point in register REGISTER.
 110 With prefix argument, store current frame configuration.
 111 Use \\[jump-to-register] to go to that location or restore that configuration.
 112 Argument is a character, naming the register."
 113   (interactive "cPoint to register: \nP")
 114   ;; Turn the marker into a file-ref if the buffer is killed.
 115   (add-hook 'kill-buffer-hook 'register-swap-out nil t)
 116   (set-register register
 117                 (if arg (list (current-frame-configuration) (point-marker))
 118                   (point-marker))))
 119
 120 (defun window-configuration-to-register (register &optional _arg)
 121   "Store the window configuration of the selected frame in register REGISTER.
 122 Use \\[jump-to-register] to restore the configuration.
 123 Argument is a character, naming the register."
 124   (interactive "cWindow configuration to register: \nP")
 125   ;; current-window-configuration does not include the value
 126   ;; of point in the current buffer, so record that separately.
 127   (set-register register (list (current-window-configuration) (point-marker))))
 128
 129 (defun frame-configuration-to-register (register &optional _arg)
 130   "Store the window configuration of all frames in register REGISTER.
 131 Use \\[jump-to-register] to restore the configuration.
 132 Argument is a character, naming the register."
 133   (interactive "cFrame configuration to register: \nP")
 134   ;; current-frame-configuration does not include the value
 135   ;; of point in the current buffer, so record that separately.
 136   (set-register register (list (current-frame-configuration) (point-marker))))
 137
 138 (defalias 'register-to-point 'jump-to-register)
 139 (defun jump-to-register (register &optional delete)
 140   "Move point to location stored in a register.
 141 If the register contains a file name, find that file.
 142 \(To put a file name in a register, you must use `set-register'.)
 143 If the register contains a window configuration (one frame) or a frame
 144 configuration (all frames), restore that frame or all frames accordingly.
 145 First argument is a character, naming the register.
 146 Optional second arg non-nil (interactively, prefix argument) says to
 147 delete any existing frames that the frame configuration doesn't mention.
 148 \(Otherwise, these frames are iconified.)"
 149   (interactive "cJump to register: \nP")
 150   (let ((val (get-register register)))
 151     (cond
 152      ((registerv-p val)
 153       (cl-assert (registerv-jump-func val) nil
 154               "Don't know how to jump to register %s"
 155               (single-key-description register))
 156       (funcall (registerv-jump-func val) (registerv-data val)))
 157      ((and (consp val) (frame-configuration-p (car val)))
 158       (set-frame-configuration (car val) (not delete))
 159       (goto-char (cadr val)))
 160      ((and (consp val) (window-configuration-p (car val)))
 161       (set-window-configuration (car val))
 162       (goto-char (cadr val)))
 163      ((markerp val)
 164       (or (marker-buffer val)
 165           (error "That register's buffer no longer exists"))
 166       (switch-to-buffer (marker-buffer val))
 167       (goto-char val))
 168      ((and (consp val) (eq (car val) 'file))
 169       (find-file (cdr val)))
 170      ((and (consp val) (eq (car val) 'file-query))
 171       (or (find-buffer-visiting (nth 1 val))
 172           (y-or-n-p (format "Visit file %s again? " (nth 1 val)))
 173           (error "Register access aborted"))
 174       (find-file (nth 1 val))
 175       (goto-char (nth 2 val)))
 176      ((and (fboundp 'semantic-foreign-tag-p)
 177            semantic-mode
 178            (semantic-foreign-tag-p val))
 179       (switch-to-buffer (semantic-tag-buffer val))
 180       (goto-char (semantic-tag-start val)))
 181      (t
 182       (error "Register doesn't contain a buffer position or configuration")))))
 183
 184 (defun register-swap-out ()
 185   "Turn markers into file-query references when a buffer is killed."
 186   (and buffer-file-name
 187        (dolist (elem register-alist)
 188          (and (markerp (cdr elem))
 189               (eq (marker-buffer (cdr elem)) (current-buffer))
 190               (setcdr elem
 191                       (list 'file-query
 192                             buffer-file-name
 193                             (marker-position (cdr elem))))))))
 194
 195 (defun number-to-register (number register)
 196   "Store a number in a register.
 197 Two args, NUMBER and REGISTER (a character, naming the register).
 198 If NUMBER is nil, a decimal number is read from the buffer starting
 199 at point, and point moves to the end of that number.
 200 Interactively, NUMBER is the prefix arg (none means nil)."
 201   (interactive "P\ncNumber to register: ")
 202   (set-register register
 203                 (if number
 204                     (prefix-numeric-value number)
 205                   (if (looking-at "\\s-*-?[0-9]+")
 206                       (progn
 207                         (goto-char (match-end 0))
 208                         (string-to-number (match-string 0)))
 209                     0))))
 210
 211 (defun increment-register (prefix register)
 212   "Augment contents of REGISTER.
 213 Interactively, PREFIX is in raw form.
 214
 215 If REGISTER contains a number, add `prefix-numeric-value' of
 216 PREFIX to it.
 217
 218 If REGISTER is empty or if it contains text, call
 219 `append-to-register' with `delete-flag' set to PREFIX."
 220   (interactive "P\ncIncrement register: ")
 221   (let ((register-val (get-register register)))
 222     (cond
 223      ((numberp register-val)
 224       (let ((number (prefix-numeric-value prefix)))
 225         (set-register register (+ number register-val))))
 226      ((or (not register-val) (stringp register-val))
 227       (append-to-register register (region-beginning) (region-end) prefix))
 228      (t (error "Register does not contain a number or text")))))
 229
 230 (defun view-register (register)
 231   "Display what is contained in register named REGISTER.
 232 The Lisp value REGISTER is a character."
 233   (interactive "cView register: ")
 234   (let ((val (get-register register)))
 235     (if (null val)
 236         (message "Register %s is empty" (single-key-description register))
 237       (with-output-to-temp-buffer "*Output*"
 238         (describe-register-1 register t)))))
 239
 240 (defun list-registers ()
 241   "Display a list of nonempty registers saying briefly what they contain."
 242   (interactive)
 243   (let ((list (copy-sequence register-alist)))
 244     (setq list (sort list (lambda (a b) (< (car a) (car b)))))
 245     (with-output-to-temp-buffer "*Output*"
 246       (dolist (elt list)
 247         (when (get-register (car elt))
 248           (describe-register-1 (car elt))
 249           (terpri))))))
 250
 251 (defun describe-register-1 (register &optional verbose)
 252   (princ "Register ")
 253   (princ (single-key-description register))
 254   (princ " contains ")
 255   (let ((val (get-register register)))
 256     (cond
 257      ((registerv-p val)
 258       (if (registerv-print-func val)
 259           (funcall (registerv-print-func val) (registerv-data val))
 260         (princ "[UNPRINTABLE CONTENTS].")))
 261
 262      ((numberp val)
 263       (princ val))
 264
 265      ((markerp val)
 266       (let ((buf (marker-buffer val)))
 267         (if (null buf)
 268             (princ "a marker in no buffer")
 269           (princ "a buffer position:\n    buffer ")
 270           (princ (buffer-name buf))
 271           (princ ", position ")
 272           (princ (marker-position val)))))
 273
 274      ((and (consp val) (window-configuration-p (car val)))
 275       (princ "a window configuration."))
 276
 277      ((and (consp val) (frame-configuration-p (car val)))
 278       (princ "a frame configuration."))
 279
 280      ((and (consp val) (eq (car val) 'file))
 281       (princ "the file ")
 282       (prin1 (cdr val))
 283       (princ "."))
 284
 285      ((and (consp val) (eq (car val) 'file-query))
 286       (princ "a file-query reference:\n    file ")
 287       (prin1 (car (cdr val)))
 288       (princ ",\n    position ")
 289       (princ (car (cdr (cdr val))))
 290       (princ "."))
 291
 292      ((consp val)
 293       (if verbose
 294           (progn
 295             (princ "the rectangle:\n")
 296             (while val
 297               (princ "    ")
 298               (princ (car val))
 299               (terpri)
 300               (setq val (cdr val))))
 301         (princ "a rectangle starting with ")
 302         (princ (car val))))
 303
 304      ((stringp val)
 305       (if (eq yank-excluded-properties t)
 306           (set-text-properties 0 (length val) nil val)
 307         (remove-list-of-text-properties 0 (length val)
 308                                         yank-excluded-properties val))
 309       (if verbose
 310           (progn
 311             (princ "the text:\n")
 312             (princ val))
 313         (cond
 314          ;; Extract first N characters starting with first non-whitespace.
 315          ((string-match (format "[^ \t\n].\\{,%d\\}"
 316                                 ;; Deduct 6 for the spaces inserted below.
 317                                 (min 20 (max 0 (- (window-width) 6))))
 318                         val)
 319           (princ "text starting with\n    ")
 320           (princ (match-string 0 val)))
 321          ((string-match "^[ \t\n]+$" val)
 322           (princ "whitespace"))
 323          (t
 324           (princ "the empty string")))))
 325      (t
 326       (princ "Garbage:\n")
 327       (if verbose (prin1 val))))))
 328
 329 (defun insert-register (register &optional arg)
 330   "Insert contents of register REGISTER.  (REGISTER is a character.)
 331 Normally puts point before and mark after the inserted text.
 332 If optional second arg is non-nil, puts mark before and point after.
 333 Interactively, second arg is non-nil if prefix arg is supplied."
 334   (interactive "*cInsert register: \nP")
 335   (push-mark)
 336   (let ((val (get-register register)))
 337     (cond
 338      ((registerv-p val)
 339       (cl-assert (registerv-insert-func val) nil
 340               "Don't know how to insert register %s"
 341               (single-key-description register))
 342       (funcall (registerv-insert-func val) (registerv-data val)))
 343      ((consp val)
 344       (insert-rectangle val))
 345      ((stringp val)
 346       (insert-for-yank val))
 347      ((numberp val)
 348       (princ val (current-buffer)))
 349      ((and (markerp val) (marker-position val))
 350       (princ (marker-position val) (current-buffer)))
 351      ((and (fboundp 'semantic-foreign-tag-p)
 352            semantic-mode
 353            (semantic-foreign-tag-p val))
 354       (semantic-insert-foreign-tag val))
 355      (t
 356       (error "Register does not contain text"))))
 357   (if (not arg) (exchange-point-and-mark)))
 358
 359 (defun copy-to-register (register start end &optional delete-flag)
 360   "Copy region into register REGISTER.
 361 With prefix arg, delete as well.
 362 Called from program, takes four args: REGISTER, START, END and DELETE-FLAG.
 363 START and END are buffer positions indicating what to copy."
 364   (interactive "cCopy to register: \nr\nP")
 365   (set-register register (filter-buffer-substring start end))
 366   (setq deactivate-mark t)
 367   (cond (delete-flag
 368          (delete-region start end))
 369         ((called-interactively-p 'interactive)
 370          (indicate-copied-region))))
 371
 372 (defun append-to-register (register start end &optional delete-flag)
 373   "Append region to text in register REGISTER.
 374 With prefix arg, delete as well.
 375 Called from program, takes four args: REGISTER, START, END and DELETE-FLAG.
 376 START and END are buffer positions indicating what to append."
 377   (interactive "cAppend to register: \nr\nP")
 378   (let ((reg (get-register register))
 379         (text (filter-buffer-substring start end))
 380         (separator (and register-separator (get-register register-separator))))
 381     (set-register
 382      register (cond ((not reg) text)
 383                     ((stringp reg) (concat reg separator text))
 384                     (t (error "Register does not contain text")))))
 385   (cond (delete-flag
 386          (delete-region start end))
 387         ((called-interactively-p 'interactive)
 388          (indicate-copied-region))))
 389
 390 (defun prepend-to-register (register start end &optional delete-flag)
 391   "Prepend region to text in register REGISTER.
 392 With prefix arg, delete as well.
 393 Called from program, takes four args: REGISTER, START, END and DELETE-FLAG.
 394 START and END are buffer positions indicating what to prepend."
 395   (interactive "cPrepend to register: \nr\nP")
 396   (let ((reg (get-register register))
 397         (text (filter-buffer-substring start end))
 398         (separator (and register-separator (get-register register-separator))))
 399     (set-register
 400      register (cond ((not reg) text)
 401                     ((stringp reg) (concat text separator reg))
 402                     (t (error "Register does not contain text")))))
 403   (cond (delete-flag
 404          (delete-region start end))
 405         ((called-interactively-p 'interactive)
 406          (indicate-copied-region))))
 407
 408 (defun copy-rectangle-to-register (register start end &optional delete-flag)
 409   "Copy rectangular region into register REGISTER.
 410 With prefix arg, delete as well.
 411 To insert this register in the buffer, use \\[insert-register].
 412
 413 Called from a program, takes four args: REGISTER, START, END and DELETE-FLAG.
 414 START and END are buffer positions giving two corners of rectangle."
 415   (interactive "cCopy rectangle to register: \nr\nP")
 416   (let ((rectangle (if delete-flag
 417                        (delete-extract-rectangle start end)
 418                      (extract-rectangle start end))))
 419     (set-register register rectangle)
 420     (when (and (null delete-flag)
 421                (called-interactively-p 'interactive))
 422       (setq deactivate-mark t)
 423       (indicate-copied-region (length (car rectangle))))))
 424
 425
 426 (provide 'register)
 427 ;;; register.el ends here