From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jambunathan K <kjambunathan@gmail.com>
Subject: Re: new exporter, conditional options according to backend
Date: Sun, 20 Jan 2013 21:52:04 +0530
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In-Reply-To: <87fw1w19v5.fsf@gmail.com> (Nicolas Goaziou's message of "Sun, 20
	Jan 2013 10:28:46 +0100")
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To: Nicolas Goaziou <n.goaziou@gmail.com>
Cc: Ezequiel Birman <stormwatch@espiga4.com.ar>, emacs-orgmode@gnu.org

Nicolas Goaziou <n.goaziou@gmail.com> writes:

> Jambunathan K <kjambunathan@gmail.com> writes:
>
>> Nicolas Goaziou <n.goaziou@gmail.com> writes:
>>
>>> #+begin_src emacs-lisp
>>> (defun my-options-change-fun (tree backend info)
>>>   (when (org-export-derived-backend-p backend 'e-beamer)
>>>     (plist-put info :with-author nil))
>>>   ;; Don't forget to return tree.
>>>   tree)
>>
>> CAVEAT: plist-put can return a different list, at times.
>>
>> I don't know enough about implementation of `plist-put' to ascertain
>> when it would return a new list.
>
> Since the OP wants to modify the values of _existing properties_ I'm
> quite sure the change will happen in place.

Look at example in Elisp manual.  New members seem to get appended.  

List being destructive is explainable if new members were to be added to
the head.  Since this is not the case, I am curious what the
implementation could be ...


>
>
> Regards,

--