bug#67611: [PATCH] Add a Pcase pattern `cl-lambda` equivalent to `cl-destructuring-bind`

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

>> Thanks for the patch.  I can only echo the sentiment already given here,
>> that making `pcase' more complex won't do much for its popularity.
> This sentiment is not unanimous.  If pcase is naturally extensible,
> using that ability is not making it more complex.  That'd be akin
> to saying "defun" is made more complex because too many functions
> are popping up.

Agreed.

> Just wanted register this position. Though I don't know for sure if
> the patch is simply adding a new extension to pcase or changing
> its core structure.

It's a pure extension.  The question is not whether the patch is good or
bad or whether it makes the existing infrastructure too complex.
It's rather where should such a thing live.

I don't think there's a clear enough need for it right now in Emacs core
to motivate its integration in Emacs proper.  Also, because several
people have expressed an opinion that leans towards recommending that
Emacs's own code should probably better avoid using this functionality.

I'd be quite happy to include such a think in GNU ELPA, OTOH.


        Stefan