Re: Listing headings in dedicated buffer with imenu.

[Heime <heimeborgia@protonmail.com>]

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On Wednesday, July 31st, 2024 at 3:59 AM, Heime <heimeborgia@protonmail.com> wrote:

> On Tuesday, July 30th, 2024 at 1:02 AM, Stephen Berman stephen.berman@gmx.net wrote:
> 
> > [I sent this yesterday but it hasn't shown up in the list, so
> > resending.]
> > 
> > On Mon, 29 Jul 2024 11:53:07 +0000 Heime heimeborgia@protonmail.com wrote:
> > 
> > > On Monday, July 29th, 2024 at 11:45 PM, Stephen Berman
> > > stephen.berman@gmx.net wrote:
> > > 
> > > > On Mon, 29 Jul 2024 11:29:07 +0000 Heime heimeborgia@protonmail.com wrote:
> > > > 
> > > > > Sent with Proton Mail secure email.
> > > > > 
> > > > > On Monday, July 29th, 2024 at 10:51 PM, Stephen Berman
> > > > > stephen.berman@gmx.net wrote:
> > > > > 
> > > > > > On Mon, 29 Jul 2024 10:41:08 +0000 Heime heimeborgia@protonmail.com wrote:
> > > > > > 
> > > > > > > Sent with Proton Mail secure email.
> > > > > > > 
> > > > > > > On Monday, July 29th, 2024 at 10:32 PM, Stephen Berman
> > > > > > > stephen.berman@gmx.net wrote:
> > > > > > > 
> > > > > > > > On Mon, 29 Jul 2024 10:26:22 +0000 Heime heimeborgia@protonmail.com wrote:
> > > > > > > > 
> > > > > > > > > Sent with Proton Mail secure email.
> > > > > > > > > 
> > > > > > > > > On Monday, July 29th, 2024 at 9:33 PM, Stephen Berman
> > > > > > > > > stephen.berman@gmx.net wrote:
> > > > > > > > > 
> > > > > > > > > > On Mon, 29 Jul 2024 08:48:38 +0000 Heime
> > > > > > > > > > heimeborgia@protonmail.com wrote:
> > > > > > > > > > 
> > > > > > > > > > > I wish to list headings in a dedicated buffer with imenu.
> > > > > > > > > > > The listing should be in the order in which headings occur
> > > > > > > > > > > in the buffer.
> > > > > > > > > > > 
> > > > > > > > > > > Have done the following, but the buffer ends up empty.
> > > > > > > > > > > 
> > > > > > > > > > > (defun vodil-imenu-bfh ()
> > > > > > > > > > > "Insert imenu headings in order in a dedicated buffer."
> > > > > > > > > > > (interactive)
> > > > > > > > > > > 
> > > > > > > > > > > (let ((imenu-items (imenu--make-index-alist t))
> > > > > > > > > > > (buffer-name "Imenu Headings"))
> > > > > > > > > > > (with-current-buffer (get-buffer-create buffer-name)
> > > > > > > > > > > (erase-buffer)
> > > > > > > > > > > (dolist (item imenu-items)
> > > > > > > > > > > (let ((name (car item))
> > > > > > > > > > > (position (cdr item)))
> > > > > > > > > > > (when (and (stringp name) (number-or-marker-p position))
> > > > > > > > > > > (insert (format "%s\n" name)))))
> > > > > > > > > > > (goto-char (point-min)))
> > > > > > > > > > > (pop-to-buffer buffer-name)))
> > > > > > > > > > 
> > > > > > > > > > It works for me, as long as imenu.el is loaded.
> > > > > > > > > > 
> > > > > > > > > > Steve Berman
> > > > > > > > > 
> > > > > > > > > What would I need to load it ?
> > > > > > > > 
> > > > > > > > One way is this:
> > > > > > > > 
> > > > > > > > (defun vodil-imenu-bfh ()
> > > > > > > > "Insert imenu headings in order in a dedicated buffer."
> > > > > > > > (interactive)
> > > > > > > > (eval-when-compile
> > > > > > > > (require 'imenu))
> > > > > > > > (let ((imenu-items (imenu--make-index-alist t))
> > > > > > > > (buffer-name "Imenu Headings"))
> > > > > > > > (with-current-buffer (get-buffer-create buffer-name)
> > > > > > > > (erase-buffer)
> > > > > > > > (dolist (item imenu-items)
> > > > > > > > (let ((name (car item))
> > > > > > > > (position (cdr item)))
> > > > > > > > (when (and (stringp name) (number-or-marker-p position))
> > > > > > > > (insert (format "%s\n" name)))))
> > > > > > > > (goto-char (point-min)))
> > > > > > > > (pop-to-buffer buffer-name)))
> > > > > > > > 
> > > > > > > > Steve Berman
> > > > > > > 
> > > > > > > Right. I have this function that I run. Running vodil-imenu-bfh
> > > > > > > after executing vodil-imenu-expr gives me rescan in the buffer.
> > > > > > > 
> > > > > > > (defun vodil-imenu-expr ()
> > > > > > > "Set up `imenu` to show a list of functions in the current buffer."
> > > > > > > 
> > > > > > > (interactive)
> > > > > > > 
> > > > > > > (setq imenu-generic-expression
> > > > > > > '( ("headings" "^;;;\\s-+\\([HM][[:digit:]]\\)\\s-+\\(.*\\)" 2)))
> > > > > > > 
> > > > > > > (imenu-add-to-menubar "Iml")
> > > > > > > (imenu--make-index-alist t)
> > > > > > > (call-interactively 'imenu))
> > > > > > 
> > > > > > What were the contents of the current buffer when you executed
> > > > > > vodil-imenu-expr?
> > > > > > 
> > > > > > Steve Berman
> > > > > 
> > > > > I had an elisp file. I ran "M-x vodil-imenu-expr" when in the file to get
> > > > > the correct imenu entries. But executing "M-x vodil-imenu-bfh" after that
> > > > > I end up with the buffer "Imenu Headings" having only rescan in it.
> > > > 
> > > > When I test your code on one of the built-in Emacs Lisp libraries,
> > > > e.g. avoid.el, then, on invoking vodil-imenu-expr, I get prompted for an
> > > > Index item, and typing TAB, the Completions buffer pops up containing
> > > > Rescan and nil. I then type C-g and then M-x vodil-imenu-bfh, and the
> > > > Imenu Headings buffer pops up containing just Rescan. However, when
> > > > I start Emacs -Q, evaluate just my emendation of your vodil-imenu-bfh
> > > > command, then visit avoid.el and invoking vodil-imenu-bfh, the
> > > > Imenu Headings buffer pops up containing this:
> > > > 
> > > > Rescan
> > > > mouse-avoidance-set-pointer-shape
> > > > mouse-avoidance-point-position
> > > > mouse-avoidance-set-mouse-position
> > > > mouse-avoidance-too-close-p
> > > > mouse-avoidance-banish-destination
> > > > mouse-avoidance-banish-mouse
> > > > mouse-avoidance-delta
> > > > mouse-avoidance-nudge-mouse
> > > > mouse-avoidance-random-shape
> > > > mouse-avoidance-ignore-p
> > > > mouse-avoidance-banish
> > > > mouse-avoidance-exile
> > > > mouse-avoidance-fancy
> > > > mouse-avoidance-mode
> > > > 
> > > > So at least the contents of avoid.el does not contain a match for your
> > > > setting of imenu-generic-expression, and presumably the same goes for
> > > > the file you tested your code on.
> > > > 
> > > > Steve Berman
> > > 
> > > Try with this to pick up (defun
> > > 
> > > ("defun" "^\\s-*(defun\\s-+\\([[:word:]-]+\\)") 1)
> > > 
> > > imenu-generic-expression works on my elisp file. Only the new buffer has rescan
> > 
> > Ok, now I see the problem: the list produced by imenu--make-index-alist
> > contains two elements: ("Rescan" . -99) is the first, and the second
> > is a list whose car is "defun" (or for your file presumably "headings")
> > and whose cdr is the list of strings from the matching elements
> > (defuns/headings) in the file with their positions. What you want to
> > loop over is just the latter list. So it should work if you use this in
> > vodil-imenu-bfh:
> > 
> > (let ((imenu-items (cdadr (imenu--make-index-alist t)))
> > ...)
> > ...)
> > 
> > Steve Berman
> 
> 
> Now things are working as I hoped.
> 

Would you be so kind to explain why I need cdadr ?  It returns the 
`cdr' of the `car' of the `cdr'.  A quite complicated thing for me.