bug#44418: 28.0.50; Spliced variable not matched as symbol in isearch

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

>> I agree that it’s easy to figure out what does the detached @ syntax
>> mean. I mainly just don’t like having two ways to do the same thing.
>> 
>> Since I don’t use search symbol myself, I can’t grasp the importance of
>> it. You apparently care about it enough to go this far, and I’m willing to
>> take your word for it.
>> 
>> You mentioned sexp queries, which reminded me that using the detached
>> syntax would allow people to interpolate capture names with quasi
>> quotes. That’s a plus for the detached syntax.
>> 
>> Ultimately I’m still on the fence for this. But if you still want to add it, please go ahead :-)
>
> I'd like to hear Stefan's opinion on this, before we make such a
> change (if we make it).

Yuan knows this area much better than I do, and I fully trust his
judgment on this.

The only I'd point out is that if we introduce a (@ ...) syntax here
we should try and phase out the old @... syntax, i.e. emit an
obsolescence warning when we bump into such code.


        Stefan