1 ;;; mail-hist.el --- Headers and message body history for outgoing mail.
2 ;; Copyright (C) 1994 Free Software Foundation, Inc.
4 ;; Author: Karl Fogel <kfogel@cs.oberlin.edu>
5 ;; Created: March, 1994
7 ;; Keywords: mail, history
9 ;; This file is part of GNU Emacs.
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 2, or (at your option)
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.
23 ;; You should have received a copy of the GNU General Public License
24 ;; along with GNU Emacs; see the file COPYING. If not, write to
25 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
27 ;; Thanks to Jim Blandy for mentioning ring.el. It saved a lot of
30 ;; To use this package, put it in a directory in your load-path, and
31 ;; put this in your .emacs file:
33 ;; (load "mail-hist" nil t)
35 ;; Or you could do it with autoloads and hooks in your .emacs:
37 ;; (add-hook 'mail-mode-hook 'mail-hist-define-keys)
38 ;; (add-hook 'mail-send-hook 'mail-hist-put-headers-into-history)
39 ;; (add-hook 'vm-mail-mode-hook 'mail-hist-define-keys) ;or rmail, etc
40 ;; (autoload 'mail-hist-define-keys "mail-hist")
41 ;; (autoload 'mail-hist-put-headers-into-history "mail-hist")
43 ;; Once it's installed, use M-p and M-n from mail headers to recover
44 ;; previous/next contents in the history for that header, or, in the
45 ;; body of the message, to recover previous/next text of the message.
46 ;; This only applies to outgoing mail -- mail-hist ignores received
49 ;; Although repeated history requests do clear out the text from the
50 ;; previous request, an isolated request just inserts its text at
51 ;; point, so that you can mix the histories of different messages
52 ;; easily. This might be confusing at times, but there should be no
53 ;; problems that undo can't handle.
59 (defun mail-hist-define-keys ()
60 "Define keys for accessing mail header history. For use in hooks."
61 (local-set-key "\M-p" 'mail-hist-previous-input)
62 (local-set-key "\M-n" 'mail-hist-next-input))
65 (add-hook 'mail-mode-hook 'mail-hist-define-keys)
68 (add-hook 'vm-mail-mode-hook 'mail-hist-define-keys)
71 (add-hook 'mail-send-hook 'mail-hist-put-headers-into-history)
73 (defvar mail-hist-header-ring-alist nil
74 "Alist of form (header-name . history-ring).
75 Used for knowing which history list to look in when the user asks for
76 previous/next input.")
78 (defvar mail-hist-history-size (or kill-ring-max 1729)
79 "*The maximum number of elements in a mail field's history.
80 Oldest elements are dumped first.")
83 (defvar mail-hist-keep-history t
84 "*Non-nil means keep a history for headers and text of outgoing mail.")
86 ;; For handling repeated history requests
87 (defvar mail-hist-access-count 0)
89 (defvar mail-hist-last-bounds nil)
90 ;; (start . end) A pair indicating the buffer positions delimiting the
91 ;; last inserted history, so it can be replaced by a new input if the
92 ;; command is repeated.
94 (defvar mail-hist-header-regexp "^[^:]*:"
95 "Regular expression for matching headers in a mail message.")
97 (defsubst mail-hist-current-header-name ()
98 "Get name of mail header point is currently in, without the colon.
99 Returns nil if not in a header, implying that point is in the body of
102 (re-search-backward (concat "^" mail-header-separator) nil t))
103 nil ; then we are in the body of the message
105 (let* ((body-start ; limit possibility of false headers
107 (re-search-forward (concat "^" mail-header-separator) nil t)))
109 (re-search-backward mail-hist-header-regexp nil t))
111 (prog2 (search-forward ":" body-start t) (1- (point)))))
115 (downcase (buffer-substring name-start name-end)))))))
117 (defsubst mail-hist-forward-header (count)
118 "Move forward COUNT headers (backward if COUNT is negative).
119 If last/first header is encountered first, stop there and returns
122 Places point on the first non-whitespace on the line following the
123 colon after the header name, or on the second space following that if
124 the header is empty."
125 (let ((boundary (save-excursion
126 (re-search-forward (concat "^" mail-header-separator) nil t))))
130 (setq boundary (save-excursion
138 (re-search-forward mail-hist-header-regexp boundary t))
139 (setq count (1- count)))
140 ;; because the current header will match too.
141 (setq count (1- count))
146 (re-search-backward mail-hist-header-regexp nil t))
147 (setq count (1+ count)))
148 ;; we end up behind the header, so must move to the front
149 (re-search-forward mail-hist-header-regexp boundary t))
150 ;; Now we are right after the colon
151 (and (looking-at "\\s-") (forward-char 1))
152 ;; return nil if didn't go as far as asked, otherwise point
155 (defsubst mail-hist-beginning-of-header ()
156 "Move to the start of the current header.
157 The start of the current header is defined as one space after the
158 colon, or just after the colon if it is not followed by whitespace."
159 ;; this is slick as all heck:
160 (if (mail-hist-forward-header -1)
161 (mail-hist-forward-header 1)
162 (mail-hist-forward-header 1)
163 (mail-hist-forward-header -1)))
165 (defsubst mail-hist-current-header-contents ()
166 "Get the contents of the mail header in which point is located."
168 (mail-hist-beginning-of-header)
169 (let ((start (point)))
170 (or (mail-hist-forward-header 1)
171 (re-search-forward (concat "^" mail-header-separator)))
173 (buffer-substring start (1- (point))))))
175 (defsubst mail-hist-get-header-ring (header)
176 "Get HEADER's history ring, or nil if none.
177 HEADER is a string without the colon."
178 (setq header (downcase header))
179 (cdr (assoc header mail-hist-header-ring-alist)))
181 (defsubst mail-hist-add-header-contents-to-ring (header &optional contents)
182 "Add the contents of HEADER to the header history ring.
183 Optional argument CONTENTS is a string which will be the contents
184 (instead of whatever's found in the header)."
185 (setq header (downcase header))
186 (let ((ring (cdr (assoc header mail-hist-header-ring-alist))))
188 ;; If the ring doesn't exist, we'll have to make it and add it
189 ;; to the mail-header-ring-alist:
191 (setq ring (make-ring mail-hist-history-size))
192 (setq mail-hist-header-ring-alist
193 (cons (cons header ring) mail-hist-header-ring-alist))))
196 (or contents (mail-hist-current-header-contents)))))
199 (defun mail-hist-put-headers-into-history ()
200 "Put headers and contents of this message into mail header history.
201 Each header has its own independent history, as does the body of the
204 This function normally would be called when the message is sent."
206 mail-hist-keep-history
208 (goto-char (point-min))
209 (while (mail-hist-forward-header 1)
210 (mail-hist-add-header-contents-to-ring
211 (mail-hist-current-header-name)))
214 (goto-char (point-min))
215 (re-search-forward (concat "^" mail-header-separator) nil)
217 (buffer-substring (point) (point-max)))))
218 (mail-hist-add-header-contents-to-ring "body" body-contents)))))
220 (defun mail-hist-previous-input (header)
221 "Insert the previous contents of this mail header or message body.
222 Moves back through the history of sent mail messages. Each header has
223 its own independent history, as does the body of the message.
225 The history only contains the contents of outgoing messages, not
227 (interactive (list (or (mail-hist-current-header-name) "body")))
228 (setq header (downcase header))
229 (let* ((ring (cdr (assoc header mail-hist-header-ring-alist)))
230 (len (ring-length ring))
231 (repeat (eq last-command 'mail-hist-input-access)))
233 (setq mail-hist-access-count
234 (ring-plus1 mail-hist-access-count len))
235 (setq mail-hist-access-count 0))
239 (message "No history for \"%s\"." header))
240 (if (ring-empty-p ring)
241 (error "\"%s\" ring is empty." header)
243 (delete-region (car mail-hist-last-bounds)
244 (cdr mail-hist-last-bounds)))
245 (let ((start (point)))
246 (insert (ring-ref ring mail-hist-access-count))
247 (setq mail-hist-last-bounds (cons start (point)))
248 (setq this-command 'mail-hist-input-access))))))
250 (defun mail-hist-next-input (header)
251 "Insert next contents of this mail header or message body.
252 Moves back through the history of sent mail messages. Each header has
253 its own independent history, as does the body of the message.
255 Although you can do so, it does not make much sense to call this
256 without having called `mail-hist-previous-header' first
257 (\\[mail-hist-previous-header]).
259 The history only contains the contents of outgoing messages, not
261 (interactive (list (or (mail-hist-current-header-name) "body")))
262 (setq header (downcase header))
263 (let* ((ring (cdr (assoc header mail-hist-header-ring-alist)))
264 (len (ring-length ring))
265 (repeat (eq last-command 'mail-hist-input-access)))
267 (setq mail-hist-access-count
268 (ring-minus1 mail-hist-access-count len))
269 (setq mail-hist-access-count 0))
273 (message "No history for \"%s\"." header))
274 (if (ring-empty-p ring)
275 (error "\"%s\" ring is empty." header)
277 (delete-region (car mail-hist-last-bounds)
278 (cdr mail-hist-last-bounds)))
279 (let ((start (point)))
280 (insert (ring-ref ring mail-hist-access-count))
281 (setq mail-hist-last-bounds (cons start (point)))
282 (setq this-command 'mail-hist-input-access))))))
286 ;; mail-hist.el ends here