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emacs/lisp/progmodes/octave-hlp.el
2005-08-26 13:42:43 +00:00

140 lines
4.4 KiB
EmacsLisp

;;; octave-hlp.el --- getting help on Octave symbols using info
;; Copyright (C) 1997, 2001, 2002, 2003, 2004, 2005
;; Free Software Foundation, Inc.
;; Author: Kurt Hornik <Kurt.Hornik@wu-wien.ac.at>
;; Author: John Eaton <jwe@bevo.che.wisc.edu>
;; Maintainer: Kurt Hornik <Kurt.Hornik@wu-wien.ac.at>
;; Keywords: languages
;; 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, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.
;;; Commentary:
;; Provides the command `octave-help' which allows index lookup of a
;; symbol in the Octave-related info files, as specified by the list
;; `octave-help-files'.
;; Other features may be added in future versions.
;;; Code:
(require 'octave-mod)
(require 'info)
(defvar octave-help-files '("octave")
"List of info files with documentation for Octave.
Default is (\"octave\").")
(defvar octave-help-lookup-alist nil
"Alist of Octave index entries for lookup.")
(defvar octave-help-completion-alist nil
"Alist of Octave index entries for completion.
The entries are of the form (VAR . VAR), where VAR runs through all
different keys in `octave-help-lookup-alist'.")
;;;###autoload
(defun octave-help (key)
"Get help on Octave symbols from the Octave info files.
Look up KEY in the function, operator and variable indices of the files
specified by `octave-help-files'.
If KEY is not a string, prompt for it with completion."
(interactive
(list
(completing-read (format "Describe Octave symbol: ")
(octave-help-get-completion-alist)
nil t)))
(if (get-buffer "*info*")
(set-buffer "*info*"))
(if (zerop (length key))
(Info-find-node (car octave-help-files) "Top")
(let ((alist (copy-alist (octave-help-get-lookup-alist)))
entry matches)
(while (setq entry (car alist))
(if (string-match key (car entry))
(add-to-list 'matches entry))
(setq alist (cdr alist)))
(if matches
(progn
(setq Info-index-alternatives matches)
(Info-index-next 0))))))
(defun octave-help-get-lookup-alist ()
"Build the index lookup alist from all Octave info files.
The files specified by `octave-help-files' are searched."
(if octave-help-lookup-alist
()
(message "Building help lookup alist...")
(let ((files octave-help-files) file key node)
(save-window-excursion
(while files
(setq file (car files))
(Info-goto-node (concat "(" file ")"))
(condition-case nil
(progn
(Info-index "")
(while
(progn
(while (re-search-forward
"^\\* \\([^(:]+\\)[^:]*: *\\(.+\\)\\.$"
nil t)
(setq key (match-string 1)
node (concat "(" file ")" (match-string 2)))
(and (string-match "\\(.*\\>\\) *$" key)
(setq key (replace-match "\\1" t nil key)))
(add-to-list 'octave-help-lookup-alist
(list key
node
(concat (concat "(" file ")")
Info-current-node)
0)))
(and (setq node (Info-extract-pointer "next" t))
(string-match
(concat "\\(Function\\|Operator\\|Variable\\) "
"\\<Index\\>")
node)))
(Info-goto-node node)))
(error nil))
(setq files (cdr files)))))
(message "Building help lookup alist...done"))
octave-help-lookup-alist)
(defun octave-help-get-completion-alist ()
"Build the index completion alist from all Octave info files.
The files specified by `octave-help-files' are searched."
(if octave-help-completion-alist
()
(message "Building help completion alist...")
(let ((alist (octave-help-get-lookup-alist)) entry)
(while alist
(setq entry (car alist))
(add-to-list 'octave-help-completion-alist
(cons (car entry) (car entry)))
(setq alist (cdr alist))))
(message "Building help completion alist...done"))
octave-help-completion-alist)
;;; provide ourself
(provide 'octave-hlp)
;;; arch-tag: df5ef8fa-76c9-44e5-9835-cb5a502c6282
;;; octave-hlp.el ends here