lisp/register.el

   1 ;;; register.el --- register commands for Emacs
   2
   3 ;; Copyright (C) 1985, 1993, 1994, 2001, 2002, 2003, 2004,
   4 ;;   2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
   5
   6 ;; Maintainer: FSF
   7 ;; Keywords: internal
   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 ;;; Global key bindings
  32
  33 ;;;###autoload (define-key ctl-x-r-map "\C-@" 'point-to-register)
  34 ;;;###autoload (define-key ctl-x-r-map [?\C-\ ] 'point-to-register)
  35 ;;;###autoload (define-key ctl-x-r-map " " 'point-to-register)
  36 ;;;###autoload (define-key ctl-x-r-map "j" 'jump-to-register)
  37 ;;;###autoload (define-key ctl-x-r-map "s" 'copy-to-register)
  38 ;;;###autoload (define-key ctl-x-r-map "x" 'copy-to-register)
  39 ;;;###autoload (define-key ctl-x-r-map "i" 'insert-register)
  40 ;;;###autoload (define-key ctl-x-r-map "g" 'insert-register)
  41 ;;;###autoload (define-key ctl-x-r-map "r" 'copy-rectangle-to-register)
  42 ;;;###autoload (define-key ctl-x-r-map "n" 'number-to-register)
  43 ;;;###autoload (define-key ctl-x-r-map "+" 'increment-register)
  44 ;;;###autoload (define-key ctl-x-r-map "w" 'window-configuration-to-register)
  45 ;;;###autoload (define-key ctl-x-r-map "f" 'frame-configuration-to-register)
  46
  47 ;;; Code:
  48
  49 (defvar register-alist nil
  50   "Alist of elements (NAME . CONTENTS), one for each Emacs register.
  51 NAME is a character (a number).  CONTENTS is a string, number, marker or list.
  52 A list of strings represents a rectangle.
  53 A list of the form (file . NAME) represents the file named NAME.
  54 A list of the form (file-query NAME POSITION) represents position POSITION
  55  in the file named NAME, but query before visiting it.
  56 A list of the form (WINDOW-CONFIGURATION POSITION)
  57  represents a saved window configuration plus a saved value of point.
  58 A list of the form (FRAME-CONFIGURATION POSITION)
  59  represents a saved frame configuration plus a saved value of point.")
  60
  61 (defun get-register (reg)
  62   "Return contents of Emacs register named REG, or nil if none."
  63   (cdr (assq reg register-alist)))
  64
  65 (defun set-register (register value)
  66   "Set contents of Emacs register named REGISTER to VALUE.  Returns VALUE.
  67 See the documentation of the variable `register-alist' for possible VALUE."
  68   (let ((aelt (assq register register-alist)))
  69     (if aelt
  70         (setcdr aelt value)
  71       (push (cons register value) register-alist))
  72     value))
  73
  74 (defun point-to-register (register &optional arg)
  75   "Store current location of point in register REGISTER.
  76 With prefix argument, store current frame configuration.
  77 Use \\[jump-to-register] to go to that location or restore that configuration.
  78 Argument is a character, naming the register."
  79   (interactive "cPoint to register: \nP")
  80   ;; Turn the marker into a file-ref if the buffer is killed.
  81   (add-hook 'kill-buffer-hook 'register-swap-out nil t)
  82   (set-register register
  83                 (if arg (list (current-frame-configuration) (point-marker))
  84                   (point-marker))))
  85
  86 (defun window-configuration-to-register (register &optional arg)
  87   "Store the window configuration of the selected frame in register REGISTER.
  88 Use \\[jump-to-register] to restore the configuration.
  89 Argument is a character, naming the register."
  90   (interactive "cWindow configuration to register: \nP")
  91   ;; current-window-configuration does not include the value
  92   ;; of point in the current buffer, so record that separately.
  93   (set-register register (list (current-window-configuration) (point-marker))))
  94
  95 (defun frame-configuration-to-register (register &optional arg)
  96   "Store the window configuration of all frames in register REGISTER.
  97 Use \\[jump-to-register] to restore the configuration.
  98 Argument is a character, naming the register."
  99   (interactive "cFrame configuration to register: \nP")
 100   ;; current-frame-configuration does not include the value
 101   ;; of point in the current buffer, so record that separately.
 102   (set-register register (list (current-frame-configuration) (point-marker))))
 103
 104 (defalias 'register-to-point 'jump-to-register)
 105 (defun jump-to-register (register &optional delete)
 106   "Move point to location stored in a register.
 107 If the register contains a file name, find that file.
 108  \(To put a file name in a register, you must use `set-register'.)
 109 If the register contains a window configuration (one frame) or a frame
 110 configuration (all frames), restore that frame or all frames accordingly.
 111 First argument is a character, naming the register.
 112 Optional second arg non-nil (interactively, prefix argument) says to
 113 delete any existing frames that the frame configuration doesn't mention.
 114 \(Otherwise, these frames are iconified.)"
 115   (interactive "cJump to register: \nP")
 116   (let ((val (get-register register)))
 117     (cond
 118      ((and (consp val) (frame-configuration-p (car val)))
 119       (set-frame-configuration (car val) (not delete))
 120       (goto-char (cadr val)))
 121      ((and (consp val) (window-configuration-p (car val)))
 122       (set-window-configuration (car val))
 123       (goto-char (cadr val)))
 124      ((markerp val)
 125       (or (marker-buffer val)
 126           (error "That register's buffer no longer exists"))
 127       (switch-to-buffer (marker-buffer val))
 128       (goto-char val))
 129      ((and (consp val) (eq (car val) 'file))
 130       (find-file (cdr val)))
 131      ((and (consp val) (eq (car val) 'file-query))
 132       (or (find-buffer-visiting (nth 1 val))
 133           (y-or-n-p (format "Visit file %s again? " (nth 1 val)))
 134           (error "Register access aborted"))
 135       (find-file (nth 1 val))
 136       (goto-char (nth 2 val)))
 137      (t
 138       (error "Register doesn't contain a buffer position or configuration")))))
 139
 140 (defun register-swap-out ()
 141   "Turn markers into file-query references when a buffer is killed."
 142   (and buffer-file-name
 143        (dolist (elem register-alist)
 144          (and (markerp (cdr elem))
 145               (eq (marker-buffer (cdr elem)) (current-buffer))
 146               (setcdr elem
 147                       (list 'file-query
 148                             buffer-file-name
 149                             (marker-position (cdr elem))))))))
 150
 151 (defun number-to-register (number register)
 152   "Store a number in a register.
 153 Two args, NUMBER and REGISTER (a character, naming the register).
 154 If NUMBER is nil, a decimal number is read from the buffer starting
 155 at point, and point moves to the end of that number.
 156 Interactively, NUMBER is the prefix arg (none means nil)."
 157   (interactive "P\ncNumber to register: ")
 158   (set-register register
 159                 (if number
 160                     (prefix-numeric-value number)
 161                   (if (looking-at "\\s-*-?[0-9]+")
 162                       (progn
 163                         (goto-char (match-end 0))
 164                         (string-to-number (match-string 0)))
 165                     0))))
 166
 167 (defun increment-register (number register)
 168   "Add NUMBER to the contents of register REGISTER.
 169 Interactively, NUMBER is the prefix arg."
 170   (interactive "p\ncIncrement register: ")
 171   (or (numberp (get-register register))
 172       (error "Register does not contain a number"))
 173   (set-register register (+ number (get-register register))))
 174
 175 (defun view-register (register)
 176   "Display what is contained in register named REGISTER.
 177 The Lisp value REGISTER is a character."
 178   (interactive "cView register: ")
 179   (let ((val (get-register register)))
 180     (if (null val)
 181         (message "Register %s is empty" (single-key-description register))
 182       (with-output-to-temp-buffer "*Output*"
 183         (describe-register-1 register t)))))
 184
 185 (defun list-registers ()
 186   "Display a list of nonempty registers saying briefly what they contain."
 187   (interactive)
 188   (let ((list (copy-sequence register-alist)))
 189     (setq list (sort list (lambda (a b) (< (car a) (car b)))))
 190     (with-output-to-temp-buffer "*Output*"
 191       (dolist (elt list)
 192         (when (get-register (car elt))
 193           (describe-register-1 (car elt))
 194           (terpri))))))
 195
 196 (defun describe-register-1 (register &optional verbose)
 197   (princ "Register ")
 198   (princ (single-key-description register))
 199   (princ " contains ")
 200   (let ((val (get-register register)))
 201     (cond
 202      ((numberp val)
 203       (princ val))
 204
 205      ((markerp val)
 206       (let ((buf (marker-buffer val)))
 207         (if (null buf)
 208             (princ "a marker in no buffer")
 209           (princ "a buffer position:\n    buffer ")
 210           (princ (buffer-name buf))
 211           (princ ", position ")
 212           (princ (marker-position val)))))
 213
 214      ((and (consp val) (window-configuration-p (car val)))
 215       (princ "a window configuration."))
 216
 217      ((and (consp val) (frame-configuration-p (car val)))
 218       (princ "a frame configuration."))
 219
 220      ((and (consp val) (eq (car val) 'file))
 221       (princ "the file ")
 222       (prin1 (cdr val))
 223       (princ "."))
 224
 225      ((and (consp val) (eq (car val) 'file-query))
 226       (princ "a file-query reference:\n    file ")
 227       (prin1 (car (cdr val)))
 228       (princ ",\n    position ")
 229       (princ (car (cdr (cdr val))))
 230       (princ "."))
 231
 232      ((consp val)
 233       (if verbose
 234           (progn
 235             (princ "the rectangle:\n")
 236             (while val
 237               (princ "    ")
 238               (princ (car val))
 239               (terpri)
 240               (setq val (cdr val))))
 241         (princ "a rectangle starting with ")
 242         (princ (car val))))
 243
 244      ((stringp val)
 245       (if (eq yank-excluded-properties t)
 246           (set-text-properties 0 (length val) nil val)
 247         (remove-list-of-text-properties 0 (length val)
 248                                         yank-excluded-properties val))
 249       (if verbose
 250           (progn
 251             (princ "the text:\n")
 252             (princ val))
 253         (cond
 254          ;; Extract first N characters starting with first non-whitespace.
 255          ((string-match (format "[^ \t\n].\\{,%d\\}"
 256                                 ;; Deduct 6 for the spaces inserted below.
 257                                 (min 20 (max 0 (- (window-width) 6))))
 258                         val)
 259           (princ "text starting with\n    ")
 260           (princ (match-string 0 val)))
 261          ((string-match "^[ \t\n]+$" val)
 262           (princ "whitespace"))
 263          (t
 264           (princ "the empty string")))))
 265      (t
 266       (princ "Garbage:\n")
 267       (if verbose (prin1 val))))))
 268
 269 (defun insert-register (register &optional arg)
 270   "Insert contents of register REGISTER.  (REGISTER is a character.)
 271 Normally puts point before and mark after the inserted text.
 272 If optional second arg is non-nil, puts mark before and point after.
 273 Interactively, second arg is non-nil if prefix arg is supplied."
 274   (interactive "*cInsert register: \nP")
 275   (push-mark)
 276   (let ((val (get-register register)))
 277     (cond
 278      ((consp val)
 279       (insert-rectangle val))
 280      ((stringp val)
 281       (insert-for-yank val))
 282      ((numberp val)
 283       (princ val (current-buffer)))
 284      ((and (markerp val) (marker-position val))
 285       (princ (marker-position val) (current-buffer)))
 286      (t
 287       (error "Register does not contain text"))))
 288   (if (not arg) (exchange-point-and-mark)))
 289
 290 (defun copy-to-register (register start end &optional delete-flag)
 291   "Copy region into register REGISTER.  With prefix arg, delete as well.
 292 Called from program, takes four args: REGISTER, START, END and DELETE-FLAG.
 293 START and END are buffer positions indicating what to copy."
 294   (interactive "cCopy to register: \nr\nP")
 295   (set-register register (filter-buffer-substring start end))
 296   (if delete-flag (delete-region start end)))
 297
 298 (defun append-to-register (register start end &optional delete-flag)
 299   "Append region to text in register REGISTER.
 300 With prefix arg, delete as well.
 301 Called from program, takes four args: REGISTER, START, END and DELETE-FLAG.
 302 START and END are buffer positions indicating what to append."
 303   (interactive "cAppend to register: \nr\nP")
 304   (let ((reg (get-register register))
 305         (text (filter-buffer-substring start end)))
 306     (set-register
 307      register (cond ((not reg) text)
 308                     ((stringp reg) (concat reg text))
 309                     (t (error "Register does not contain text")))))
 310   (if delete-flag (delete-region start end)))
 311
 312 (defun prepend-to-register (register start end &optional delete-flag)
 313   "Prepend region to text in register REGISTER.
 314 With prefix arg, delete as well.
 315 Called from program, takes four args: REGISTER, START, END and DELETE-FLAG.
 316 START and END are buffer positions indicating what to prepend."
 317   (interactive "cPrepend to register: \nr\nP")
 318   (let ((reg (get-register register))
 319         (text (filter-buffer-substring start end)))
 320     (set-register
 321      register (cond ((not reg) text)
 322                     ((stringp reg) (concat text reg))
 323                     (t (error "Register does not contain text")))))
 324   (if delete-flag (delete-region start end)))
 325
 326 (defun copy-rectangle-to-register (register start end &optional delete-flag)
 327   "Copy rectangular region into register REGISTER.
 328 With prefix arg, delete as well.  To insert this register
 329 in the buffer, use \\[insert-register].
 330
 331 Called from a program, takes four args: REGISTER, START, END and DELETE-FLAG.
 332 START and END are buffer positions giving two corners of rectangle."
 333   (interactive "cCopy rectangle to register: \nr\nP")
 334   (set-register register
 335                 (if delete-flag
 336                     (delete-extract-rectangle start end)
 337                   (extract-rectangle start end))))
 338
 339 (provide 'register)
 340 ;; arch-tag: ce14dd68-8265-475f-9341-5d4ec5a53035
 341 ;;; register.el ends here