Re: [babel] What is `, (backquote comma)?

[Thorsten <quintfall@googlemail.com>]

Štěpán Němec <stepnem@gmail.com> writes:

> On Wed, 21 Sep 2011 19:37:42 +0200
> Thorsten wrote:
>
>> in org-babel-expand-body:scheme (and
>> e.g. org-babel-expand-body:emacs-lisp) I encounter something like this:
>>
>> (lambda (var)  (format "%S" (print `(,(car var) ',(cdr var)))))
>> 	
>> While this part
>> `(,(car var) ...)
>> is explained in the manual (backquote and unquote), this part
>> `(... ',(cdr var))
>> is a bit mysterious to me, and I do not find information about
>> backquote( ... backquote comma ())
>> in the manuals or the web.
>>
>> Is that Emacs Lisp? What does that mean?
>
> Note it's not "`,", which would indeed be a no-op, but "',", which here
> means "evaluate the form after "," and quote the result", IOW, the "'"
> is just left there (for the same reason you also get to see the even
> more funny-looking "`'," and other variations sometimes). Really nothing
> new if you've read the backquote section of the Elisp manual.

thanks Nick and Stepan, 

"evaluate the form after "," and quote the result"

that made me understand what its all about. 
I just read the backquote section Elisp manual, it does not cover these
strange combiniations of barely distinguable characters, but I may haved
missed it - its a thick book. 

Cheers
Thorsten