1
0
mirror of https://git.savannah.gnu.org/git/emacs.git synced 2024-12-04 08:47:11 +00:00
emacs/lisp/docref.el
1998-03-07 18:19:38 +00:00

297 lines
10 KiB
EmacsLisp
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

;;; docref.el --- Simple cross references for Elisp documentation strings
;; Copyright (C) 1994 Free Software Foundation, Inc.
;; Author: Vadim Geshel <vadik@unas.cs.kiev.ua>
;; Created: 12 Jul 1994
;; Keywords: docs, help, lisp
;; original name was cross-ref.el.
;; 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., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.
;;; Commentary:
;; This package allows you to use a simple form of cross references in
;; your Emacs Lisp documentation strings. Cross-references look like
;; \\(type@[label@]data), where type defines a method for retrieving
;; reference information, data is used by a method routine as an argument,
;; and label "represents" the reference in text. If label is absent, data
;; is used instead.
;;
;; Special reference labeled `back', when present, can be used to return
;; to the previous contents of help buffer.
;;
;; Cross-referencing currently is intended for use in doc strings only
;; and works only in temporary buffers (created by `with-output-to-temp-buffer').
;; List of temp buffers in which cross-referencing is to be active is specified
;; by variable DOCREF-BUFFERS-LIST, which contains only "*Help*" by default.
;;
;; Documentation strings for this package's functions and variables can serve
;; as examples of usage.
;;
;;; Customization:
;;
;; See source. The main customization variable is `docref-methods-alist'.
;; It consists of (type . function) pairs, where type is a string which
;; corresponds to type in cross-references and function is called with
;; one argument - reference `data' - when a reference is activated.
;;
;;; Installation:
;;
;; Place this file somewhere in your load-path, byte-compiled it, and add
;; (require 'cross-ref)
;; to your .emacs.
;;; Code:
;; User customizable variables
(defgroup docref nil
"Simple cross references for Elisp documentation strings."
:prefix "docref-"
:group 'help
:group 'lisp
:group 'docs)
(defcustom docref-highlight-p t
"*If non-nil, \\(f@docref-subst) highlights cross-references.
Under window system it highlights them with face defined by
\\(v@docref-highlight-face), on character terminal highlighted references
look like cross-references in info mode."
:type 'boolean
:group 'docref)
(defcustom docref-highlight-face 'highlight
"*Face used to highlight cross-references (used by \\(f@docref-subst))"
:type 'face
:group 'docref)
(defcustom docref-methods-alist
'(("f" . docref-describe-function) ; reference to a function documentation
("v" . docref-describe-variable) ; reference to a variable documentation
("F" . docref-read-file) ; reference to a file contents
("s" . docref-use-string) ; reference to a string
("V" . docref-use-variable-value) ; reference to variable value
("0" . beep)) ; just highlighted text
"Alist which maps cross-reference ``types'' to retrieval functions.
The car of each element is a string that serves as `type' in cross-references.
\(See \\(f@docref-subst)). The cdr is a function of one argument,
to be called to find this reference."
:type '(repeat (cons string function))
:group 'docref)
(defcustom docref-back-label "\nback"
"Label to use by \\(f@docref-subst) for the go-back reference."
:type 'string
:group 'docref)
(defvar docref-back-reference nil
"If non-nil, this is a go-back reference to add to the current buffer.
The value specifies how to go back. It should be suitable for use
as the second argument to \\(f@docref-insert-label).
\\(f@docref-subst) uses this to set up the go-back reference.")
(defvar docref-last-active-buffer)
;;;###autoload
(defun docref-setup ()
"Process docref cross-references in the current buffer.
See also \\(f@docref-subst)."
(interactive)
(docref-subst (current-buffer))
(docref-mode))
(defvar docref-mode-map nil)
(or docref-mode-map
(let ((map (make-sparse-keymap)))
(define-key map [mouse-2] 'docref-follow-mouse)
(define-key map "\C-c\C-b" 'docref-go-back)
(define-key map "\C-c\C-c" 'docref-follow)
(setq docref-mode-map map)))
(defun docref-mode ()
"Major mode for help buffers that contain cross references.
To follow a reference, move to it and type \\[docref-follow], or use
\\[docref-follow-mouse]. The command \\[docref-go-back] can used to go
back to where you came from."
(interactive)
(kill-all-local-variables)
(setq major-mode 'docref-mode)
(setq mode-name "Docref")
(use-local-map docref-mode-map)
(run-hooks 'docref-mode))
(defun docref-subst (buf)
"Parse documentation cross-references in buffer BUF.
Find cross-reference information in a buffer and
highlight them with face defined by \\(v@docref-highlight-face).
Cross-reference has the following format: \\ (TYPE[@LABEL]@DATA), where
TYPE defines method used to retrieve xref data (like reading from file or
calling \\(f@describe-function)), DATA is an argument to this method
\(like file name or function name), and LABEL is displayed in text using
\\(v@docref-highlight-face).
The special reference `back' can be used to return back.
The variable \\(v@docref-back-label) specifies the label to use for that.
See \\(v@docref-methods-alist) for currently defined methods."
(interactive "b")
(save-excursion
(set-buffer buf)
(goto-char (point-min))
;; The docref-seen property indicates that we have processed this
;; buffer's contents already, so don't do it again.
(if (not (get-text-property (point-min) 'docref-seen))
(let ((old-modified (buffer-modified-p)))
(while (re-search-forward "[\\](\\([^\)\@]+\\)\\(@[^\)\@]+\\)?@\\([^\)]*\\))"
nil t)
(let* ((start (match-beginning 0))
(type (buffer-substring (match-beginning 1) (match-end 1)))
(data (buffer-substring (match-beginning 3) (match-end 3)))
(label
(if (match-beginning 2)
(buffer-substring (+ (match-beginning 2) 1) (match-end 2))
data)))
(replace-match "" t)
(docref-insert-label label (cons type data))))
;; Make a back-reference in this buffer, if desired.
;; (This is true if called from docref-follow.)
(if docref-back-reference
(progn
(goto-char (point-max))
(put-text-property (point-min) (1+ (point-min))
'docref-back-position (point))
(docref-insert-label docref-back-label docref-back-reference)))
(put-text-property (point-min) (1+ (point-min)) 'docref-seen t)
(set-buffer-modified-p old-modified)))))
(defun docref-insert-label (string ref)
(let ((label (concat string))
(pos (point)))
;; decorate the label
(let ((leading-space-end (save-match-data
(if (string-match "^\\([ \t\n]+\\)" label)
(match-end 1)
0)))
(trailing-space-start (save-match-data
(if (string-match "\\([ \t\n]+\\)$" label)
(match-beginning 1)
(length label)))))
(if docref-highlight-p
(if (not window-system)
(setq label
(concat (substring label 0 leading-space-end)
"(*note "
(substring label leading-space-end trailing-space-start)
")"
(substring label trailing-space-start)))
;; window-system
(put-text-property leading-space-end
trailing-space-start
'face docref-highlight-face label)))
(put-text-property 0 (length label) 'docref ref label)
(insert label))))
(defun docref-follow-mouse (click)
"Follow the cross-reference that you click on."
(interactive "e")
(save-excursion
(let* ((start (event-start click))
(window (car start))
(pos (car (cdr start)))
(docref-last-active-buffer (current-buffer)))
(set-buffer (window-buffer window))
(docref-follow pos))))
(defun docref-go-back ()
"Go back to the previous contents of help buffer."
(interactive)
(let ((pos (get-text-property (point-min) 'docref-back-position)))
(if pos
(docref-follow pos)
(error "No go-back reference"))))
(defun docref-follow (&optional pos)
"Follow cross-reference at point.
For the cross-reference format, see \\(f@docref-subst).
The special reference named `back' can be used to return back"
(interactive)
(or pos (setq pos (point)))
(let ((docref-data (get-text-property pos 'docref)))
(if docref-data
;; There is a reference at point. Follow it.
(let* ((type (car docref-data))
(name (cdr docref-data))
(method (assoc type docref-methods-alist))
(cur-contents (buffer-string))
(opoint (point))
(docref-back-reference (cons "s" cur-contents))
success)
(if (null method)
(error "Unknown cross-reference type: %s" type))
(unwind-protect
(save-excursion
(funcall (cdr method) name)
(setq success t))
(or success
(progn
;; (cdr method) got an error.
;; Put back the text that we had.
(erase-buffer)
(insert cur-contents)
(goto-char opoint)))
(set-buffer-modified-p nil))))))
;; Builtin methods for accessing a reference.
(defun docref-describe-function (data)
(save-excursion
(if (boundp 'docref-last-active-buffer)
(set-buffer docref-last-active-buffer))
(describe-function (intern data))))
(defun docref-describe-variable (data)
(save-excursion
(if (boundp 'docref-last-active-buffer)
(set-buffer docref-last-active-buffer))
(describe-variable (intern data))))
(defun docref-read-file (data)
(with-output-to-temp-buffer (buffer-name)
(erase-buffer)
(insert-file-contents (expand-file-name data))))
(defun docref-use-string (data)
(with-output-to-temp-buffer (buffer-name)
(erase-buffer)
(insert data)))
(defun docref-use-variable-value (data)
(let ((sym (intern data)))
(with-output-to-temp-buffer (buffer-name)
(erase-buffer)
(princ (symbol-value sym)))))
(provide 'docref)
;;; docref.el ends here