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 (defun get-register (register)
  80   "Return contents of Emacs register named REGISTER, or nil if none."
  81   (cdr (assq register register-alist)))
  82
  83 (defun set-register (register value)
  84   "Set contents of Emacs register named REGISTER to VALUE.  Returns VALUE.
  85 See the documentation of the variable `register-alist' for possible VALUEs."
  86   (let ((aelt (assq register register-alist)))
  87     (if aelt
  88         (setcdr aelt value)
  89       (push (cons register value) register-alist))
  90     value))
  91
  92 (defun point-to-register (register &optional arg)
  93   "Store current location of point in register REGISTER.
  94 With prefix argument, store current frame configuration.
  95 Use \\[jump-to-register] to go to that location or restore that configuration.
  96 Argument is a character, naming the register."
  97   (interactive "cPoint to register: \nP")
  98   ;; Turn the marker into a file-ref if the buffer is killed.
  99   (add-hook 'kill-buffer-hook 'register-swap-out nil t)
 100   (set-register register
 101                 (if arg (list (current-frame-configuration) (point-marker))
 102                   (point-marker))))
 103
 104 (defun window-configuration-to-register (register &optional _arg)
 105   "Store the window configuration of the selected frame in register REGISTER.
 106 Use \\[jump-to-register] to restore the configuration.
 107 Argument is a character, naming the register."
 108   (interactive "cWindow configuration to register: \nP")
 109   ;; current-window-configuration does not include the value
 110   ;; of point in the current buffer, so record that separately.
 111   (set-register register (list (current-window-configuration) (point-marker))))
 112
 113 (defun frame-configuration-to-register (register &optional _arg)
 114   "Store the window configuration of all frames in register REGISTER.
 115 Use \\[jump-to-register] to restore the configuration.
 116 Argument is a character, naming the register."
 117   (interactive "cFrame configuration to register: \nP")
 118   ;; current-frame-configuration does not include the value
 119   ;; of point in the current buffer, so record that separately.
 120   (set-register register (list (current-frame-configuration) (point-marker))))
 121
 122 (defalias 'register-to-point 'jump-to-register)
 123 (defun jump-to-register (register &optional delete)
 124   "Move point to location stored in a register.
 125 If the register contains a file name, find that file.
 126 \(To put a file name in a register, you must use `set-register'.)
 127 If the register contains a window configuration (one frame) or a frame
 128 configuration (all frames), restore that frame or all frames accordingly.
 129 First argument is a character, naming the register.
 130 Optional second arg non-nil (interactively, prefix argument) says to
 131 delete any existing frames that the frame configuration doesn't mention.
 132 \(Otherwise, these frames are iconified.)"
 133   (interactive "cJump to register: \nP")
 134   (let ((val (get-register register)))
 135     (cond
 136      ((registerv-p val)
 137       (cl-assert (registerv-jump-func val) nil
 138               "Don't know how to jump to register %s"
 139               (single-key-description register))
 140       (funcall (registerv-jump-func val) (registerv-data val)))
 141      ((and (consp val) (frame-configuration-p (car val)))
 142       (set-frame-configuration (car val) (not delete))
 143       (goto-char (cadr val)))
 144      ((and (consp val) (window-configuration-p (car val)))
 145       (set-window-configuration (car val))
 146       (goto-char (cadr val)))
 147      ((markerp val)
 148       (or (marker-buffer val)
 149           (error "That register's buffer no longer exists"))
 150       (switch-to-buffer (marker-buffer val))
 151       (goto-char val))
 152      ((and (consp val) (eq (car val) 'file))
 153       (find-file (cdr val)))
 154      ((and (consp val) (eq (car val) 'file-query))
 155       (or (find-buffer-visiting (nth 1 val))
 156           (y-or-n-p (format "Visit file %s again? " (nth 1 val)))
 157           (error "Register access aborted"))
 158       (find-file (nth 1 val))
 159       (goto-char (nth 2 val)))
 160      ((and (fboundp 'semantic-foreign-tag-p)
 161            semantic-mode
 162            (semantic-foreign-tag-p val))
 163       (switch-to-buffer (semantic-tag-buffer val))
 164       (goto-char (semantic-tag-start val)))
 165      (t
 166       (error "Register doesn't contain a buffer position or configuration")))))
 167
 168 (defun register-swap-out ()
 169   "Turn markers into file-query references when a buffer is killed."
 170   (and buffer-file-name
 171        (dolist (elem register-alist)
 172          (and (markerp (cdr elem))
 173               (eq (marker-buffer (cdr elem)) (current-buffer))
 174               (setcdr elem
 175                       (list 'file-query
 176                             buffer-file-name
 177                             (marker-position (cdr elem))))))))
 178
 179 (defun number-to-register (number register)
 180   "Store a number in a register.
 181 Two args, NUMBER and REGISTER (a character, naming the register).
 182 If NUMBER is nil, a decimal number is read from the buffer starting
 183 at point, and point moves to the end of that number.
 184 Interactively, NUMBER is the prefix arg (none means nil)."
 185   (interactive "P\ncNumber to register: ")
 186   (set-register register
 187                 (if number
 188                     (prefix-numeric-value number)
 189                   (if (looking-at "\\s-*-?[0-9]+")
 190                       (progn
 191                         (goto-char (match-end 0))
 192                         (string-to-number (match-string 0)))
 193                     0))))
 194
 195 (defun increment-register (number register)
 196   "Add NUMBER to the contents of register REGISTER.
 197 Interactively, NUMBER is the prefix arg."
 198   (interactive "p\ncIncrement register: ")
 199   (or (numberp (get-register register))
 200       (error "Register does not contain a number"))
 201   (set-register register (+ number (get-register register))))
 202
 203 (defun view-register (register)
 204   "Display what is contained in register named REGISTER.
 205 The Lisp value REGISTER is a character."
 206   (interactive "cView register: ")
 207   (let ((val (get-register register)))
 208     (if (null val)
 209         (message "Register %s is empty" (single-key-description register))
 210       (with-output-to-temp-buffer "*Output*"
 211         (describe-register-1 register t)))))
 212
 213 (defun list-registers ()
 214   "Display a list of nonempty registers saying briefly what they contain."
 215   (interactive)
 216   (let ((list (copy-sequence register-alist)))
 217     (setq list (sort list (lambda (a b) (< (car a) (car b)))))
 218     (with-output-to-temp-buffer "*Output*"
 219       (dolist (elt list)
 220         (when (get-register (car elt))
 221           (describe-register-1 (car elt))
 222           (terpri))))))
 223
 224 (defun describe-register-1 (register &optional verbose)
 225   (princ "Register ")
 226   (princ (single-key-description register))
 227   (princ " contains ")
 228   (let ((val (get-register register)))
 229     (cond
 230      ((registerv-p val)
 231       (if (registerv-print-func val)
 232           (funcall (registerv-print-func val) (registerv-data val))
 233         (princ "[UNPRINTABLE CONTENTS].")))
 234
 235      ((numberp val)
 236       (princ val))
 237
 238      ((markerp val)
 239       (let ((buf (marker-buffer val)))
 240         (if (null buf)
 241             (princ "a marker in no buffer")
 242           (princ "a buffer position:\n    buffer ")
 243           (princ (buffer-name buf))
 244           (princ ", position ")
 245           (princ (marker-position val)))))
 246
 247      ((and (consp val) (window-configuration-p (car val)))
 248       (princ "a window configuration."))
 249
 250      ((and (consp val) (frame-configuration-p (car val)))
 251       (princ "a frame configuration."))
 252
 253      ((and (consp val) (eq (car val) 'file))
 254       (princ "the file ")
 255       (prin1 (cdr val))
 256       (princ "."))
 257
 258      ((and (consp val) (eq (car val) 'file-query))
 259       (princ "a file-query reference:\n    file ")
 260       (prin1 (car (cdr val)))
 261       (princ ",\n    position ")
 262       (princ (car (cdr (cdr val))))
 263       (princ "."))
 264
 265      ((consp val)
 266       (if verbose
 267           (progn
 268             (princ "the rectangle:\n")
 269             (while val
 270               (princ "    ")
 271               (princ (car val))
 272               (terpri)
 273               (setq val (cdr val))))
 274         (princ "a rectangle starting with ")
 275         (princ (car val))))
 276
 277      ((stringp val)
 278       (if (eq yank-excluded-properties t)
 279           (set-text-properties 0 (length val) nil val)
 280         (remove-list-of-text-properties 0 (length val)
 281                                         yank-excluded-properties val))
 282       (if verbose
 283           (progn
 284             (princ "the text:\n")
 285             (princ val))
 286         (cond
 287          ;; Extract first N characters starting with first non-whitespace.
 288          ((string-match (format "[^ \t\n].\\{,%d\\}"
 289                                 ;; Deduct 6 for the spaces inserted below.
 290                                 (min 20 (max 0 (- (window-width) 6))))
 291                         val)
 292           (princ "text starting with\n    ")
 293           (princ (match-string 0 val)))
 294          ((string-match "^[ \t\n]+$" val)
 295           (princ "whitespace"))
 296          (t
 297           (princ "the empty string")))))
 298      (t
 299       (princ "Garbage:\n")
 300       (if verbose (prin1 val))))))
 301
 302 (defun insert-register (register &optional arg)
 303   "Insert contents of register REGISTER.  (REGISTER is a character.)
 304 Normally puts point before and mark after the inserted text.
 305 If optional second arg is non-nil, puts mark before and point after.
 306 Interactively, second arg is non-nil if prefix arg is supplied."
 307   (interactive "*cInsert register: \nP")
 308   (push-mark)
 309   (let ((val (get-register register)))
 310     (cond
 311      ((registerv-p val)
 312       (cl-assert (registerv-insert-func val) nil
 313               "Don't know how to insert register %s"
 314               (single-key-description register))
 315       (funcall (registerv-insert-func val) (registerv-data val)))
 316      ((consp val)
 317       (insert-rectangle val))
 318      ((stringp val)
 319       (insert-for-yank val))
 320      ((numberp val)
 321       (princ val (current-buffer)))
 322      ((and (markerp val) (marker-position val))
 323       (princ (marker-position val) (current-buffer)))
 324      ((and (fboundp 'semantic-foreign-tag-p)
 325            semantic-mode
 326            (semantic-foreign-tag-p val))
 327       (semantic-insert-foreign-tag val))
 328      (t
 329       (error "Register does not contain text"))))
 330   (if (not arg) (exchange-point-and-mark)))
 331
 332 (defun copy-to-register (register start end &optional delete-flag)
 333   "Copy region into register REGISTER.
 334 With prefix arg, delete as well.
 335 Called from program, takes four args: REGISTER, START, END and DELETE-FLAG.
 336 START and END are buffer positions indicating what to copy."
 337   (interactive "cCopy to register: \nr\nP")
 338   (set-register register (filter-buffer-substring start end))
 339   (if delete-flag (delete-region start end)))
 340
 341 (defun append-to-register (register start end &optional delete-flag)
 342   "Append region to text in register REGISTER.
 343 With prefix arg, delete as well.
 344 Called from program, takes four args: REGISTER, START, END and DELETE-FLAG.
 345 START and END are buffer positions indicating what to append."
 346   (interactive "cAppend to register: \nr\nP")
 347   (let ((reg (get-register register))
 348         (text (filter-buffer-substring start end)))
 349     (set-register
 350      register (cond ((not reg) text)
 351                     ((stringp reg) (concat reg text))
 352                     (t (error "Register does not contain text")))))
 353   (if delete-flag (delete-region start end)))
 354
 355 (defun prepend-to-register (register start end &optional delete-flag)
 356   "Prepend region to text in register REGISTER.
 357 With prefix arg, delete as well.
 358 Called from program, takes four args: REGISTER, START, END and DELETE-FLAG.
 359 START and END are buffer positions indicating what to prepend."
 360   (interactive "cPrepend to register: \nr\nP")
 361   (let ((reg (get-register register))
 362         (text (filter-buffer-substring start end)))
 363     (set-register
 364      register (cond ((not reg) text)
 365                     ((stringp reg) (concat text reg))
 366                     (t (error "Register does not contain text")))))
 367   (if delete-flag (delete-region start end)))
 368
 369 (defun copy-rectangle-to-register (register start end &optional delete-flag)
 370   "Copy rectangular region into register REGISTER.
 371 With prefix arg, delete as well.
 372 To insert this register in the buffer, use \\[insert-register].
 373
 374 Called from a program, takes four args: REGISTER, START, END and DELETE-FLAG.
 375 START and END are buffer positions giving two corners of rectangle."
 376   (interactive "cCopy rectangle to register: \nr\nP")
 377   (set-register register
 378                 (if delete-flag
 379                     (delete-extract-rectangle start end)
 380                   (extract-rectangle start end))))
 381
 382 (provide 'register)
 383 ;;; register.el ends here