GNU bug report logs - #44885
28.0.50; [PATCH] ElDoc buffer mode and separator

Previous Next

Full log

View this message in rfc822 format

From: João Távora <joaotavora <at> gmail.com>
To: Andrii Kolomoiets <andreyk.mad <at> gmail.com>
Cc: 44885 <at> debbugs.gnu.org
Subject: bug#44885: 28.0.50; [PATCH] ElDoc buffer mode and separator
Date: Sat, 28 Nov 2020 23:54:36 +0000

Andrii Kolomoiets <andreyk.mad <at> gmail.com> writes:

> Hi,
>
> Patch attached.
>
> The configurable separator will make it possible to show multiple docs
> in user pleasant way.

Thanks. The patch looks generally good but it has an important flaw that
can be fixed. See comments below.

> The mode will allow tweak ElDoc doc buffer appearance by adding hooks.

Yes.  I also have some ideas about how to sophisticate this buffer.

One of them involves having some backends, like the Elisp backends,
transmit a special key on the side -- much like :thing or :face -- that
specifies a function that fills in the whole buffer.  Thus, M-x eldoc in
a symbol of the Elisp buffer could eventually format this Eldoc doc
buffer much in the same way that currently M-x describe-symbol does.

And thus the Elisp disconnect between M-x eldoc and M-x describe-* would
be bridged.

The only incompatibility I see between my idea and your current proposal
is the major mode that you picked for the Eldoc doc buffer.  I wonder if
you could make it inherit from Help mode?  Then it would glue better
with my idea.

> With little customization and custom display function in
> display-buffer-alist 'M-x eldoc-doc-buffer' can show the ElDoc buffer
> like some kind of tooltip.

Very interesting. Can you share the display-buffer-alist hack that
allowed you to do this?  I didn't think about the possibility of
tweaking it like this, but it's certainly "legal".  I wonder if you
cann't do the same by adding a different function to
eldoc-display-functions, which was how I intented it to work.

> +(defvar eldoc-doc-mode-map
> +  (let ((map (make-sparse-keymap)))
> +    (suppress-keymap map)
> +    (define-key map "q" 'quit-window)
> +    (define-key map " " 'scroll-up-command)
> +    (define-key map [?\S-\ ] 'scroll-down-command)
> +    (define-key map "\C-?" 'scroll-down-command)
> +    (define-key map "?" 'describe-mode)
> +    (define-key map "h" 'describe-mode)
> +    (define-key map ">" 'end-of-buffer)
> +    (define-key map "<" 'beginning-of-buffer)
> +    map)
> +  "Keymap used in ElDoc documentation buffer.")
> +
> +(define-derived-mode eldoc-doc-mode fundamental-mode "ElDoc doc"
> +  "Major mode for ElDoc documentation buffer."
> +  (setq buffer-read-only t))

As I said above, I wonder if inheriting from help-mode wouldn't give us
most of this for free.  Maybe it would bring us _too much_ though...  So
some inheritance snipping would be needed.

>                   do (insert this-doc)
> -                 when rest do (insert "\n")
> +                 when rest do (insert eldoc-doc-buffer-separator)

I like this and I like the separator, however, notice that the current
implementation of the eldoc-display-in-echo-area also uses this buffer
as an implementation detail.  So this would break eldoc-display-in-echo
area.

The solution would be for eldoc-display-in-echo-area to use its own
"hidden" buffer and then eldoc-display-in-buffer would be free to format
the buffer as it sees fit.

So you could extract the buffer-formatting code to a common helper, use
it in eldoc-display-in-echo-area with a "\n" separator and in
eldoc-display-in-buffer with an arbitrary user-chosen separator.  The
performance hit of formatting two buffers would likely be negligible.

João

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.