Re: generate 1) virtual index

[Juri Linkov]

>> Since it was proposed in
>>
>> http://lists.gnu.org/archive/html/emacs-devel/2007-06/msg00454.html
>>
>> instead of implementing `Info-index-occur' I arrived to a different
>> command name: `info-apropos-current-file'.  I don't know if this is
>> a better name, but by its functionality this command is very similar
>> to `info-apropos' that works only on the current Info file.
>
> I'm not sure, but I think we are saying the same or similar things.
> Is that right?  I had forgotten your proposal cited in the link above,
> but it seems about the same. Is there a difference or something
> additional that you are saying?

Below is a simple patch that implements this:

Index: lisp/info.el
===================================================================
RCS file: /sources/emacs/emacs/lisp/info.el,v
retrieving revision 1.505
diff -c -w -b -r1.505 info.el
*** lisp/info.el        28 Aug 2007 10:15:23 -0000      1.505
--- lisp/info.el        23 Sep 2007 20:40:07 -0000
***************
*** 2931,2940 ****
        (progn (beginning-of-line) t)  ;; non-nil for recursive call
        (goto-char (point-min)))))
  
  ;;;###autoload
! (defun info-apropos (string)
    "Grovel indices of all known Info files on your system for STRING.
! Build a menu of the possible matches."
    (interactive "sIndex apropos: ")
    (unless (string= string "")
      (let ((pattern (format "\n\\* +\\([^\n]*%s[^\n]*\\):[ 
\t]+\\([^\n]+\\)\\.\\(?:[ \t\n]*(line +\\([0-9]+\\))\\)?"
--- 2931,2947 ----
        (progn (beginning-of-line) t)  ;; non-nil for recursive call
        (goto-char (point-min)))))
  
+ (defun info-apropos-current-file (string)
+   "Search indices of the current Info file for STRING.
+ Build a menu of the possible matches."
+   (interactive "sIndex apropos current Info file: ")
+   (info-apropos string t))
+ 
  ;;;###autoload
! (defun info-apropos (string &optional current)
    "Grovel indices of all known Info files on your system for STRING.
! Build a menu of the possible matches.
! If CURRENT is non-nil, search indices only in the current Info file."
    (interactive "sIndex apropos: ")
    (unless (string= string "")
      (let ((pattern (format "\n\\* +\\([^\n]*%s[^\n]*\\):[ 
\t]+\\([^\n]+\\)\\.\\(?:[ \t\n]*(line +\\([0-9]+\\))\\)?"
***************
*** 2943,2950 ****
--- 2950,2960 ----
          (ohist-list Info-history-list)
          (current-node Info-current-node)
          (current-file Info-current-file)
+         (supports-index-cookies Info-file-supports-index-cookies)
          manuals matches node nodes)
        (let ((Info-fontify-maximum-menu-size nil))
+       (if current
+           (setq manuals (list Info-current-file))
          (Info-directory)
          ;; current-node and current-file are nil when they invoke info-apropos
          ;; as the first Info command, i.e. info-apropos loads info.el.  In 
that
***************
*** 2959,2965 ****
        (while (re-search-forward "\\*.*: *(\\([^)]+\\))" nil t)
          ;; add-to-list makes sure we don't have duplicates in `manuals',
          ;; so that the following dolist loop runs faster.
!         (add-to-list 'manuals (match-string 1)))
        (dolist (manual (nreverse manuals))
          (message "Searching %s" manual)
          (condition-case err
--- 2969,2975 ----
          (while (re-search-forward "\\*.*: *(\\([^)]+\\))" nil t)
            ;; add-to-list makes sure we don't have duplicates in `manuals',
            ;; so that the following dolist loop runs faster.
!           (add-to-list 'manuals (match-string 1))))
        (dolist (manual (nreverse manuals))
          (message "Searching %s" manual)
          (condition-case err
***************
*** 2991,2996 ****
--- 3001,3009 ----
        (with-current-buffer (get-buffer-create " *info-apropos*")
          (erase-buffer)
          (insert "\n\^_\nFile: apropos, Node: Index, Up: (dir)\n")
+         (when supports-index-cookies
+           (insert "\0\b[index\0\b]\n")
+           (set (make-local-variable 'Info-file-supports-index-cookies) 
supports-index-cookies))
          (insert "* Menu: \nNodes whose indices contain `" string "':\n\n")
          (dolist (entry (nreverse matches))
            (insert
***************
*** 3177,3182 ****
--- 3190,3196 ----
    (define-key Info-mode-map "g" 'Info-goto-node)
    (define-key Info-mode-map "h" 'Info-help)
    (define-key Info-mode-map "i" 'Info-index)
+   (define-key Info-mode-map "I" 'info-apropos-current-file)
    (define-key Info-mode-map "l" 'Info-history-back)
    (define-key Info-mode-map "L" 'Info-history)
    (define-key Info-mode-map "m" 'Info-menu)

-- 
Juri Linkov
http://www.jurta.org/emacs/