Re: [FR] org-colview.el, add annotation for functions summary-types

[Ihor Radchenko <yantar92@posteo.net>]

Sławomir Grochowski <slawomir.grochowski@gmail.com> writes:

>> See `help--symbol-completion-table-affixation'.
>
> It's a private function and I need only a part of it. 
> Should I extract that part and create a new function? Like this below?
>
> (defun first-line-docstring (fun)
>   (let* ((doc (condition-case nil (documentation fun) (error nil)))
>          (doc (and doc (substring doc 0 (string-search "\n" doc)))))
>     (if doc
>         (format " -- %s" doc)
>       "")))

This would make sense, yes.  Probably for org-macs.el

Why not applying faces?

>> I'd also prefer using a proper completing-read API instead of
>> `completion-extra-properties' - by using `completion-extra-properties',
>> we disallow users from utilizing this variable.
>
> OK. Based on this example
> https://emacs.stackexchange.com/questions/74547/completing-read-search-also-in-annotations
> I came up with this snippet below:
>
> (completing-read
>  "Summary: "
>  (lambda (s pred flag)
>    (pcase flag
>      ('t (all-completions s
>                             (mapcar #'car org-columns-summary-types-default)
>                             pred))
>      ('metadata (list 'metadata
>                       (cons 'annotation-function
>                             (lambda (c)
>                               (first-line-docstring
>                                (cdr (assoc c org-columns-summary-types-default))))))))))

Looks reasonable.
Although, I'd prefer to avoid lambda here and simply make it into a
proper function. Just like `org-tags-completion-function'.

-- 
Ihor Radchenko // yantar92,
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