bug#39512: 28.0.50; Add command isearch-yank-region

[Ergus via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

On Thu, Apr 15, 2021 at 11:52:03PM +0300, Juri Linkov wrote:
>> So without any other alternative, `M-s M-.` will be good enough. In
>> general it would be better (for consistency) if we "reserve" `M-.`
>> "suffixes" for future thing-at-point-or-region commands right?
>>
>>> In the previous message you sent a link to `ivy-thing-at-point` that
>>> also uses (thing-at-point 'url) and also tries to get a filename at point.
>>> Do you think `thing-at-point-or-region` should do the same?
>>
>> With the interactive experience in mind I think this could make sense as
>> it does in `ivy-thing-at-point`.
>>
>> In my opinion from the api point of view, the important modification
>> could be the method to know the "kind the thing" detected after calling
>> the function (region, word, symbol, url) but also a function to get the
>> bounds instead of the text (like bounds-of-thing-at-point-or-region).
>
>I continued trying to do what you suggested some time ago
>and immediately stumbled upon a question what "thing"
>to use by default as an argument of '(thing-at-point thing)'?
>
>Trying these priorities:
>
>(or (thing-at-point 'region)
>    (thing-at-point 'url)
>    ;; (thing-at-point 'filename)
>    ;; (thing-at-point 'list)
>    (thing-at-point 'symbol))
>
>has several problems:
>
>1. There is no such "thing" as 'region'.  Maybe could be added to thingatpt.el?
>
This was actually the most important part in the request. Maybe an extra
optional parameter like use-region could be added to
bounds-of-thing-at-point that uses the active region when
region-active-p or use-region-p.

As I already mentioned; IMO the idea is to follow the same logic than here:

https://github.com/abo-abo/swiper/blob/471d644d6bdd7d5dc6ca4efb405e6a6389dff245/ivy.el#L427

where `(thing-at-point 'region)` is basically the first branch in the
cond.

>2. 'url' returns nil when there is no url at point, good.  But
>   'filename' returns non-nil on any string, not only on real filenames.
>
'filename' must match a local filename or a path... but it may be costly
to check in the filesystem if the match is an existing file... specially
when using tramp... so I don't have a solution for this. But the linked
code uses some ffap api for that.

>3. It would be nice to use (thing-at-point 'list) only when point
>   is on the open/close parens.  This is how double-clicking by mouse
>   selects the thing at point of mouse click.  When clicked on a paren,
>   the whole list is selected by 'mouse-start-end'.
>   'isearch-forward-thing-at-point' could be the same logic.

now I use C-M-SPC for this selection and then M-w to copy and C-s
C-y. If you add the command, then it will save the M-w and the C-y to
copy the region, because region will be already active... But will
require the M-s prefix any way... so not 2 but at least 1 bind will be
saved. 

You can consider this option in the future if you want...