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Message-ID:  <55F88867.90907@morningstar2.co.uk>
Date:         Tue, 15 Sep 2015 22:06:47 +0100
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From: Joseph Wright <joseph.wright@MORNINGSTAR2.CO.UK>
Subject: Re: interface for test on driver being used
To: LATEX-L@LISTSERV.UNI-HEIDELBERG.DE
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Envelope-To: <rainer.schoepf@GMX.NET>
Status: R

On 15/09/2015 09:12, Alexander Grahn wrote:
> Good morning,
> 
> There is a number of functions in the new l3sys package for testing the
> current engine, but I am still missing a public interface for testing
> the driver. The l3drivers package internally uses some mechanism to
> distinguish between pdfmode, dvips, dvipdfmx and xdvipdfmx. Will there be
> such a testing be included in the public interface of expl3 one day?
> 
> Currently, I am still using a combination if the `ifpdf' package and the
> \*_if_engine* functions for the purpose of driver detection.
> 
> Kind regards,
> Alexander

Hello Alexander,

Adding material to l3sys is on the 'to do' list but there are several
things there for 'soon'! I can certainly look to add a DVI/PDF test
(definitely one to do).

In terms of drivers, we could/should move that code to l3sys anyway. The
question of to what extent any code of this form should be outside of
the kernel is tricky: for say drawing I can imagine something akin to
pgf's system layer with a low-level public interface on top (there are a
limited number of well-defined operations). For what you want (I'm
guessing) that's not so clear: I've not looked in detail but I assume
the entire set up for movie inclusion is highly system-dependent.

Joseph