1;;; refer.el --- look up references in bibliography files
2
3;; Copyright (C) 1992, 1996, 2001, 2002, 2003, 2004,
4;;   2005, 2006, 2007 Free Software Foundation, Inc.
5
6;; Author: Ashwin Ram <ashwin@cc.gatech.edu>
7;; Maintainer: Gernot Heiser <gernot@acm.org>
8;; Adapted-By: ESR
9;; Keywords: bib
10
11;; This file is part of GNU Emacs.
12
13;; GNU Emacs is free software; you can redistribute it and/or modify
14;; it under the terms of the GNU General Public License as published by
15;; the Free Software Foundation; either version 2, or (at your option)
16;; any later version.
17
18;; GNU Emacs is distributed in the hope that it will be useful,
19;; but WITHOUT ANY WARRANTY; without even the implied warranty of
20;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21;; GNU General Public License for more details.
22
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 the
25;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
26;; Boston, MA 02110-1301, USA.
27
28;;; Commentary:
29
30;; Functions to look up references in bibliography files given lists of
31;; keywords, similar to refer(1).  I don't use tags since tags on .bib files
32;; only picks up the cite key, where as refer-find-entry looks for occurrences
33;; of keywords anywhere in the bibliography entry.
34;;
35;; To use:
36;;      (autoload 'refer-find-entry "refer" nil t)
37;; or   (require 'refer)
38;;
39;;      To look for an article by Knuth about semaphores:
40;;          Invoke refer-find-entry, then in response to the Keywords: prompt,
41;;          say: Knuth semaphores (a blank-separated list of keywords to be used
42;;          as search strings).
43;;
44;;      To continue the previous search, i.e., to search for the next occurrence
45;;      of the keywords, use refer-find-next-entry, or invoke refer-find-entry
46;;      with a prefix argument.
47;;
48;;	Once you've found the entry you want to reference, invoke
49;;	refer-yank-key to insert it at point in the current buffer
50;;	(typically as the argument of a \cite{} command).
51;;
52;;	I use (define-key tex-mode-map    "\C-c\C-y"  'refer-yank-key)
53;;	to bind this often-used function to a key in (la)tex-mode.
54;;
55;;      If the list of bibliography files changes, reinitialize the variable
56;;      refer-bib-files.
57;;
58;; To customize:
59;;      See variables refer-bib-files, refer-cache-bib-files and
60;;      refer-bib-files-regexp.  By default, these are set up so that refer
61;;      looks for the keywords you specify in all the .bib files in the current
62;;      directory.
63;;
64;;      The only assumption I make about bib files is that they contain a bunch
65;;      of entries, one to a paragraph.  refer-find-entry searches paragraph by
66;;      paragraph, looking for a paragraph containing all the keywords
67;;      specified.  So you should be able to use pretty much any bib file with
68;;      this code.  If your bib file does not use paragraphs to separate
69;;      entries, try setting the paragraph-start/separate variables, or changing
70;;      the (forward-paragraph 1) call in refer-find-entry-in-file.
71
72;;; Code:
73
74(provide 'refer)
75
76(defgroup refer nil
77  "Look up references in bibliography files."
78  :prefix "refer-"
79  :group 'wp)
80
81(defcustom refer-bib-directory nil
82  "Directory, or list of directories, to search for \\.bib files.
83Can be set to 'bibinputs or 'texinputs, in which case the environment
84variable BIBINPUTS or TEXINPUTS, respectively, is used to obtain a
85list of directories.  Useful only if `refer-bib-files' is set to 'dir or
86a list of file names (without directory).  A value of nil indicates the
87current working directory.
88
89If `refer-bib-directory' is 'bibinputs or 'texinputs, it is setq'd to
90the appropriate list of directories when it is first used.
91
92Note that an empty directory is interpreted by BibTeX as indicating
93the default search path.  Since Refer does not know that default path,
94it cannot search it.  Include that path explicitly in your BIBINPUTS
95environment if you really want it searched (which is not likely to
96happen anyway)."
97  :type '(choice (repeat directory) (const bibinputs) (const texinputs))
98  :group 'refer)
99
100(defcustom refer-bib-files 'dir
101  "*List of \\.bib files to search for references,
102or one of the following special values:
103nil  = prompt for \\.bib file (if visiting a \\.bib file, use it as default)
104auto = read \\.bib file names from appropriate command in buffer (see
105       `refer-bib-files-regexp') unless the buffer's mode is `bibtex-mode',
106       in which case only the buffer is searched
107dir  = use all \\.bib files in directories referenced by `refer-bib-directory'.
108
109If a specified file doesn't exist and has no extension, a \\.bib extension
110is automatically tried.
111
112If `refer-bib-files' is nil, auto or dir, it is setq'd to the appropriate
113list of files when it is first used if `refer-cache-bib-files' is t.  If
114`refer-cache-bib-files' is nil, the list of \\.bib files to use is re-read
115each time it is needed."
116  :type '(choice (repeat file) (const nil) (const auto) (const dir))
117  :group 'refer)
118
119(defcustom refer-cache-bib-files t
120  "*Variable determining whether the value of `refer-bib-files' should be cached.
121If t, initialize the value of refer-bib-files the first time it is used.  If
122nil, re-read the list of \\.bib files depending on the value of `refer-bib-files'
123each time it is needed."
124  :type 'boolean
125  :group 'refer)
126
127(defcustom refer-bib-files-regexp "\\\\bibliography"
128  "*Regexp matching a bibliography file declaration.
129The current buffer is expected to contain a line such as
130\\bibliography{file1,file2,file3}
131which is read to set up `refer-bib-files'.  The regexp must specify the command
132\(such as \\bibliography) that is used to specify the list of bib files.  The
133command is expected to specify a file name, or a list of comma-separated file
134names, within curly braces.
135If a specified file doesn't exist and has no extension, a \\.bib extension
136is automatically tried."
137  :type 'regexp
138  :group 'refer)
139
140(make-variable-buffer-local 'refer-bib-files)
141(make-variable-buffer-local 'refer-cache-bib-files)
142(make-variable-buffer-local 'refer-bib-directory)
143
144;;; Internal variables
145(defvar refer-saved-state nil)
146(defvar refer-previous-keywords nil)
147(defvar refer-saved-pos nil)
148(defvar refer-same-file nil)
149
150(defun refer-find-entry (keywords &optional continue)
151   "Find entry in refer-bib-files containing KEYWORDS.
152If KEYWORDS is nil, prompt user for blank-separated list of keywords.
153If CONTINUE is non-nil, or if called interactively with a prefix arg,
154look for next entry by continuing search from previous point."
155   (interactive (list nil current-prefix-arg))
156   (or keywords (setq keywords (if continue
157                                   refer-previous-keywords
158                                 (read-string "Keywords: "))))
159   (setq refer-previous-keywords keywords)
160   (refer-find-entry-internal keywords continue))
161
162(defun refer-find-next-entry ()
163   "Find next occurrence of entry in `refer-bib-files'.  See `refer-find-entry'."
164   (interactive)
165   (refer-find-entry-internal refer-previous-keywords t))
166
167(defun refer-yank-key ()
168  "Inserts at point in current buffer the \"key\" field of the entry
169found on the last `refer-find-entry' or `refer-find-next-entry'."
170  (interactive)
171  (let ((old-point (point)))
172    (insert
173     (save-window-excursion
174       (save-excursion
175         (find-file (car refer-saved-state))
176         (if (looking-at
177              "[ \t\n]*@\\s-*[a-zA-Z][a-zA-Z0-9]*\\s-*{\\s-*\\([^ \t\n,]+\\)\\s-*,")
178             (buffer-substring (match-beginning 1) (match-end 1))
179           (error "Cannot find key for entry in file %s"
180                  (car refer-saved-state))))))
181    (if (not (= (point) old-point))
182      (set-mark old-point))))
183
184(defun refer-find-entry-internal (keywords continue)
185   (let ((keywords-list (refer-convert-string-to-list-of-strings keywords))
186         (old-buffer (current-buffer))
187         (old-window (selected-window))
188         (new-window (selected-window))
189         (files (if continue
190                    refer-saved-state
191                  (setq refer-saved-pos nil)
192                  (refer-get-bib-files)))
193         (n 0)
194         (found nil)
195         (file nil))
196     ;; find window in which to display bibliography file.
197     ;; if a bibliography file is already displayed in a window, use
198     ;; that one, otherwise use any window other than the current one
199     (setq new-window
200	   (get-window-with-predicate
201	    (lambda (w)
202	      (while (and (not (null (setq file (nth n files))))
203			  (setq n (1+ n))
204			  (not (string-equal file
205					     (buffer-file-name
206					      (window-buffer w))))))
207	      file)))
208     (unless new-window
209       ;; didn't find bib file in any window:
210       (when (one-window-p 'nomini)
211	 (setq old-window (split-window)))
212       (setq new-window (next-window old-window 'nomini)))
213     (select-window (if refer-same-file
214                        old-window
215                      new-window))  ; the window in which to show the bib file
216     (catch 'found
217       (while files
218         (let ((file (cond ((file-exists-p (car files)) (car files))
219                           ((file-exists-p (concat (car files) ".bib"))
220                            (concat (car files) ".bib")))))
221           (setq refer-saved-state files)
222           (if file
223               (if (refer-find-entry-in-file keywords-list file refer-saved-pos)
224                   (progn
225                     (setq refer-saved-pos (point))
226                     (recenter 0)
227                     (throw 'found (find-file file)))
228                 (setq refer-saved-pos nil
229                       files (cdr files)))
230             (progn (ding)
231		    (message "Scanning %s... No such file" (car files))
232                    (sit-for 1)
233                    (setq files (cdr files))))))
234       (ding)
235       (message "Keywords \"%s\" not found in any \.bib file" keywords))
236     (select-window old-window)))
237
238(defun refer-find-entry-in-file (keywords-list file &optional old-pos)
239   (message "Scanning %s..." file)
240   (expand-file-name file)
241   (set-buffer (find-file-noselect file))
242   (find-file file)
243   (if (not old-pos)
244       (goto-char (point-min))
245     (goto-char old-pos)
246     (forward-paragraph 1))
247   (let ((begin (point))
248         (end 0)
249         (found nil))
250     (while (and (not found)
251                 (not (eobp)))
252       (forward-paragraph 1)
253       (setq end (point))
254       (setq found
255             (refer-every (function (lambda (keyword)
256                                (goto-char begin)
257                                (re-search-forward keyword end t)))
258                    keywords-list))
259       (if (not found)
260           (progn
261             (setq begin end)
262             (goto-char begin))))
263     (if found
264         (progn (goto-char begin)
265                (re-search-forward "\\W" nil t)
266                (message "Scanning %s... found" file))
267       (progn (message "Scanning %s... not found" file)
268              nil))))
269
270(defun refer-every (pred l)
271  (cond ((null l) nil)
272	((funcall pred (car l))
273	 (or (null (cdr l))
274	     (refer-every pred (cdr l))))))
275
276(defun refer-convert-string-to-list-of-strings (s)
277   (let ((current (current-buffer))
278         (temp-buffer (get-buffer-create "*refer-temp*")))
279      (set-buffer temp-buffer)
280      (erase-buffer)
281      (insert (regexp-quote s))
282      (goto-char (point-min))
283      (insert "(\"")
284      (while (re-search-forward "[ \t]+" nil t)
285         (replace-match "\" \"" t t))
286      (goto-char (point-max))
287      (insert "\")")
288      (goto-char (point-min))
289      (prog1 (read temp-buffer)
290         (set-buffer current))))
291
292(defun refer-expand-files (file-list dir-list)
293  (let (file files dir dirs)
294    (while (setq file (car file-list))
295      (setq dirs (copy-alist dir-list))
296      (while (setq dir (car dirs))
297        (if (file-exists-p (expand-file-name file dir))
298            (setq files (append files (list (expand-file-name file dir)))
299                  dirs  nil)
300          (if (file-exists-p (expand-file-name (concat file ".bib") dir))
301              (setq files (append files (list (expand-file-name (concat file ".bib")
302                                                                dir)))
303                    dirs  nil)
304            (setq dirs (cdr dirs)))))
305      (setq file-list (cdr file-list)))
306    files))
307
308(defun refer-get-bib-files ()
309  (let* ((dir-list
310          (cond
311           ((null refer-bib-directory)
312            '("."))
313           ((or (eq refer-bib-directory 'texinputs)
314                (eq refer-bib-directory 'bibinputs))
315            (let ((envvar (getenv (if (eq refer-bib-directory 'texinputs)
316                                      "TEXINPUTS"
317                                    "BIBINPUTS")))
318                  (dirs nil))
319              (if (null envvar)
320                  (setq envvar "."))
321              (while (string-match ":" envvar)
322		(let ((dir (substring envvar 0 (match-beginning 0))))
323		  (if (and (not (string-equal "" dir))
324                           (file-directory-p dir))
325		      (setq dirs (append (list (expand-file-name dir nil))
326                                         dirs))))
327                (setq envvar (substring envvar (match-end 0))))
328	      (if (and (not (string-equal "" envvar))
329                       (file-directory-p envvar))
330		  (setq dirs (append (list envvar) dirs)))
331              (setq dirs (nreverse dirs))))
332	   ((listp refer-bib-directory)
333	    refer-bib-directory)
334           (t
335            (list refer-bib-directory))))
336         (files
337           (cond
338            ((null refer-bib-files)
339             (list (expand-file-name
340                    (if (eq major-mode 'bibtex-mode)
341                        (read-file-name
342                         (format ".bib file (default %s): "
343                                 (file-name-nondirectory
344                                  (buffer-file-name)))
345                         (file-name-directory (buffer-file-name))
346                         (file-name-nondirectory (buffer-file-name))
347                         t)
348                      (read-file-name ".bib file: " nil nil t)))))
349            ((eq refer-bib-files 'auto)
350             (let ((files
351                    (save-excursion
352                      (if (setq refer-same-file (eq major-mode 'bibtex-mode))
353                          (list buffer-file-name)
354                        (if (progn
355                              (goto-char (point-min))
356                              (re-search-forward (concat refer-bib-files-regexp
357                                                         "\\s-*\{") nil t))
358                            (let ((files (list (buffer-substring
359                                                (point)
360                                                (progn
361                                                  (re-search-forward "[,\}]"
362                                                                     nil t)
363                                                  (backward-char 1)
364                                                  (point))))))
365                              (while (not (looking-at "\}"))
366                                (setq files (append files
367                                                    (list (buffer-substring
368                                                           (progn (forward-char 1)
369                                                                  (point))
370                                                           (progn (re-search-forward
371                                                                   "[,\}]" nil t)
372                                                                  (backward-char 1)
373                                                                  (point)))))))
374                              files)
375                          (error (concat "No \\\\bibliography command in this "
376                                         "buffer, can't read refer-bib-files")))))))
377               (refer-expand-files files dir-list)))
378            ((eq refer-bib-files 'dir)
379             (let ((dirs (nreverse dir-list))
380                   dir files)
381               (while (setq dir (car dirs))
382                 (setq files
383                       (append (directory-files dir t "\\.bib$")
384                               files))
385                 (setq dirs (cdr dirs)))
386               files))
387            ((and (listp refer-bib-files)
388                  (or (eq refer-bib-directory 'texinputs)
389                      (eq refer-bib-directory 'bibinputs)))
390             (refer-expand-files refer-bib-files dir-list))
391            ((listp refer-bib-files) refer-bib-files)
392            (t (error "Invalid value for refer-bib-files: %s"
393                      refer-bib-files)))))
394    (if (or (eq refer-bib-directory 'texinputs)
395            (eq refer-bib-directory 'bibinputs))
396        (setq refer-bib-directory dir-list))
397    (if refer-cache-bib-files
398        (setq refer-bib-files files))
399    files))
400
401;;; arch-tag: 151f641b-e79b-462b-9a29-a95c3793f300
402;;; refer.el ends here
403