bug#19790: [PATCH] destructive splicing in backquote

[Lars Ingebrigtsen]

Lars Ingebrigtsen <larsi@gnus.org> writes:

> Robin Templeton <robin@terpri.org> writes:
>
>> Common Lisp and MACLISP define comma-dot syntax for destructive splicing
>> in backquote expressions. The Elisp reader reads ",.x" as "(\,\. x)"
>> (like ",@"), but the resulting forms are not processed by the backquote
>> library. A patch follows that adds CL-compatible comma-dot support.
>>
>> Originally reported by at Artur Malabarba in
>> <http://lists.gnu.org/archive/html/emacs-devel/2015-01/msg00624.html>.
>
> I think the conclusion to the discussion was that we do not want to
> support the ,. operation in Emacs Lisp.
>
> (setq .foo 1)
>
> `((,.foo))
> => (((\,\. foo)))
>
> So we should remove this feature completely, because that's obviously a
> bug...

It still is.  Anybody object to removing it?  And where is it even
defined?

-- 
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   bloggy blog: http://lars.ingebrigtsen.no