Re: eldoc recursion error

[James N. V. Cash <james.cash@occasionallycogent.com>]

Kyle Meyer <kyle@kyleam.com> writes:

> Using lexical-let here is problematic because it's obsolete since Emacs
> 24.  Taking a quick glance, I don't see any issues with switching this
> file over to lexical binding by adding " -*- lexical-binding: t; -*-" to
> the first line.

Cool, will do. I was concerned that the lexical-binding stanza was
missing for a reason, but I'll give it a shot.

> Also, why use
>
>     (doc-funs (symbol-value 'eldoc-documentation-functions))
>
> rather than
>
>     (doc-funs eldoc-documentation-functions)
>
> ?

Good question...I was doing that just because the original code does
~(symbol-value 'eldoc-documentation-function)~ and I assumed there was
some reason I didn't understand for doing so.

>> +         (lambda ()
>> +           (let ((eldoc-documentation-functions doc-funs))
>> +             (funcall eldoc-documentation-strategy))))
>> +             (and eldoc-documentation-function
>> +            (symbol-value 'eldoc-documentation-function))))
>
> nit: Please switch this to the Elisp style of indenting the `else' arm
> less than the `then' arm.

Oops, will do.

>> -(defun org-eldoc-documentation-function (&rest _ignored)
>> +(defun org-eldoc-documentation-function (&optional callback)
>
> Perhaps even with the callback parameter the &rest should stay around.
> The docstring of eldoc-documentation-functions makes me nervous because
> it says "each hook function is called with _at least_ one argument" (my
> emphasis).

Good call, will do.

> Hmm, I think the more complete approach you put together for
> org-eldoc-get-mode-local-documentation-function, along with your change
> to consider the callback parameter here, means we don't need to bother
> with the condition-case/wrong-number-of-arguments dance.  The callback
> alone should be a reliable indication we're on Emacs 28, in which case
> we can expect the function to accept a callback argument (even if they
> ignore it like python-eldoc-function does).

I was just thinking more about this, and I'm concerned I might need to
change things around a little bit more. The closure that
org-eldoc-get-mode-local-documentation-function now returns under Emacs
28 doesn't take any arguments and instead lets the
eldoc-documentation-strategy function create its own new callback.

I think the current approach will appear to work when the documentation
function returns a value directly, but if it uses the callback, then I
think that it won't, since it invokes a new, separate callback.

I will take another crack at addressing this and send another patch shortly.

> Thanks again for working on this.

My pleasure!