--- /dev/null
+;;; refer.el --- look up references in bibliography files.
+
+;; Copyright (C) 1992 Free Software Foundation, Inc.
+
+;; Author: Ashwin Ram <Ram-Ashwin@cs.yale.edu>
+;; Adapted-By: ESR
+;; Keywords: bib
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 2, or (at your option)
+;; any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs; see the file COPYING. If not, write to
+;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+
+;;; Commentary:
+;;
+;; Functions to look up references in bibliography files given lists of
+;; keywords, similar to refer(1). I don't use tags since tags on .bib files
+;; only picks up the cite key, where as refer-find-entry looks for occurrences
+;; of keywords anywhere in the bibliography entry.
+;;
+;; To use:
+;; (autoload 'refer-find-entry "refer" nil t)
+;; or (require 'refer)
+;;
+;; To look for an article by Knuth about semaphores:
+;; Invoke refer-find-entry, then in response to the Keywords: prompt,
+;; say: Knuth semaphores (a blank-separated list of keywords to be used
+;; as search strings).
+;;
+;; To continue the previous search, i.e., to search for the next occurrence
+;; of the keywords, use refer-find-next-entry, or invoke refer-find-entry
+;; with a prefix argument.
+;;
+;; If the list of bibliography files changes, reinitialize the variable
+;; refer-bib-files.
+;;
+;; To customize:
+;; See variables refer-bib-files, refer-cache-bib-files and
+;; refer-bib-files-regexp. By default, these are set up so that refer
+;; looks for the keywords you specify in all the .bib files in the current
+;; directory.
+;;
+;; The only assumption I make about bib files is that they contain a bunch
+;; of entries, one to a paragraph. refer-find-entry searches paragraph by
+;; paragraph, looking for a paragraph containing all the keywords
+;; specified. So you should be able to use pretty much any bib file with
+;; this code. If your bib file does not use paragraphs to separate
+;; entries, try setting the paragraph-start/separate variables, or changing
+;; the (forward-paragraph 1) call in refer-find-entry-in-file.
+
+;;; ChangeLog:
+;;
+;; 01/08/89 Ashwin Ram <Ram-Ashwin@cs.yale.edu>
+;; Initial release.
+;;
+
+;;; Code:
+
+(provide 'refer)
+
+(defvar refer-bib-files 'dir
+ "*List of \\.bib files to search for references,
+or one of the following special values:
+nil = prompt for \\.bib file (if visiting a \\.bib file, use it as default)
+auto = read \\.bib file names from appropriate command in buffer (see refer-bib-files-regexp)
+dir = use all \\.bib files in current directory.
+
+If a specified file doesn't exist and has no extension, a \\.bib extension
+is automatically tried.
+
+If refer-bib-files is nil, auto or dir, it is setq'd to the appropriate
+list of files when it is first used if refer-cache-bib-files is t. If
+refer-cache-bib-files is nil, the list of \\.bib files to use is re-read
+each time it is needed.")
+
+(defvar refer-cache-bib-files t
+ "*Variable determining whether the value of refer-bib-files should be cached.
+If t, initialize the value of refer-bib-files the first time it is used. If
+nil, re-read the list of \\.bib files depending on the value of refer-bib-files
+each time it is needed.")
+
+(defvar refer-bib-files-regexp "\\\\bibliography"
+ "*Regexp matching a bibliography file declaration.
+The current buffer is expected to contain a line such as
+\\bibliography{file1,file2,file3}
+which is read to set up refer-bib-files. The regexp must specify the command
+\(such as \\bibliography) that is used to specify the list of bib files. The
+command is expected to specify a file name, or a list of comma-separated file
+names, within curly braces.
+If a specified file doesn't exist and has no extension, a \\.bib extension
+is automatically tried.")
+
+(make-variable-buffer-local 'refer-bib-files)
+(make-variable-buffer-local 'refer-cache-bib-files)
+
+(defun refer-find-entry (keywords &optional continue)
+ "Find entry in refer-bib-files containing KEYWORDS.
+If KEYWORDS is nil, prompt user for blank-separated list of keywords.
+If CONTINUE is t, or if called interactively with a prefix arg, look for next
+entry by continuing search from previous point."
+ (interactive (list nil current-prefix-arg))
+ (or keywords (setq keywords (if continue
+ refer-previous-keywords
+ (read-string "Keywords: "))))
+ (setq refer-previous-keywords keywords)
+ (refer-find-entry-internal keywords continue))
+
+(defun refer-find-next-entry ()
+ "Find next occurrence of entry in refer-bib-files. See refer-find-entry."
+ (interactive)
+ (refer-find-entry-internal refer-previous-keywords t))
+
+(defun refer-find-entry-internal (keywords continue)
+ (let ((keywords-list (convert-string-to-list-of-strings keywords))
+ (files (if continue
+ refer-saved-state
+ (refer-get-bib-files))))
+ (catch 'found
+ (while files
+ (let ((file (cond ((file-exists-p (car files)) (car files))
+ ((file-exists-p (concat (car files) ".bib")) (concat (car files) ".bib")))))
+ (setq refer-saved-state files)
+ (if file
+ (if (refer-find-entry-in-file keywords-list file continue)
+ (throw 'found (find-file file))
+ (setq files (cdr files)))
+ (progn (message "Scanning %s... No such file" (car files) (ding))
+ (sit-for 1)
+ (setq files (cdr files))))))
+ (message "Keywords \"%s\" not found in any \.bib file" keywords (ding)))))
+
+(defun refer-find-entry-in-file (keywords-list file &optional continue)
+ (message "Scanning %s..." file) ; (expand-file-name file)
+ (set-buffer (find-file-noselect file))
+ (if continue
+ (forward-paragraph 1)
+ (goto-char (point-min)))
+ (let ((begin (point))
+ (end 0)
+ (found nil))
+ (while (and (not found)
+ (not (eobp)))
+ (forward-paragraph 1)
+ (setq end (point))
+ (setq found
+ (every (function (lambda (keyword)
+ (goto-char begin)
+ (re-search-forward keyword end t)))
+ keywords-list))
+ (if (not found)
+ (progn
+ (setq begin end)
+ (goto-char begin))))
+ (if found
+ (progn (goto-char begin)
+ (re-search-forward "\\W" nil t)
+ (message "Scanning %s... found" file))
+ (progn (message "Scanning %s... not found" file)
+ nil))))
+
+(defun every (pred l)
+ (cond ((null l) nil)
+ ((funcall pred (car l))
+ (or (null (cdr l))
+ (every pred (cdr l))))))
+
+(defun convert-string-to-list-of-strings (s)
+ (let ((current (current-buffer))
+ (temp-buffer (get-buffer-create "*refer-temp*")))
+ (set-buffer temp-buffer)
+ (erase-buffer)
+ (insert (regexp-quote s))
+ (goto-char (point-min))
+ (insert "(\"")
+ (while (re-search-forward "[ \t]+" nil t)
+ (replace-match "\" \"" t t))
+ (goto-char (point-max))
+ (insert "\")")
+ (goto-char (point-min))
+ (prog1 (read temp-buffer)
+ (set-buffer current))))
+
+(defun refer-get-bib-files ()
+ (let ((files
+ (cond ((null refer-bib-files)
+ (list (expand-file-name
+ (if (eq major-mode 'bibtex-mode)
+ (read-file-name (format ".bib file: (default %s) " (file-name-nondirectory (buffer-file-name)))
+ (file-name-directory (buffer-file-name))
+ (file-name-nondirectory (buffer-file-name))
+ t)
+ (read-file-name ".bib file: " nil nil t)))))
+ ((listp refer-bib-files) refer-bib-files)
+ ((eq refer-bib-files 'auto)
+ (save-excursion
+ (if (progn (goto-char (point-min))
+ (re-search-forward (concat refer-bib-files-regexp "\{") nil t))
+ (let ((files (list (buffer-substring (point)
+ (progn (re-search-forward "[,\}]" nil t)
+ (backward-char 1)
+ (point))))))
+ (while (not (looking-at "\}"))
+ (setq files (append files
+ (list (buffer-substring (progn (forward-char 1)
+ (point))
+ (progn (re-search-forward "[,\}]" nil t)
+ (backward-char 1)
+ (point)))))))
+ files)
+ (error "No \\\\bibliography command in this buffer, can't read refer-bib-files"))))
+ ((eq refer-bib-files 'dir)
+ (directory-files "." t "\\.bib$"))
+ (t (error "Illegal value for refer-bib-files: %s" refer-bib-files)))))
+ (if refer-cache-bib-files
+ (setq refer-bib-files files))
+ files))
+
+;;; refer.el ends here