[OS X TeX] altpdflatex - back compatibility please

Gerben Wierda Gerben.Wierda at rna.nl
Thu Oct 13 08:19:02 EDT 2005

Thanks for thinking along.

> Perhaps you forget how stable a thing tex (and gwtex) is.  For 90 percent
> of the tex users, there is no reason to upgrade, and there may be many old
> installations around.  Certainly on this list, people are very advanced
> tex
> users and we are all very thankful for the constant development and
> improvements, and the new bells and whistles, but the average user (not
> subscribed to this list) may not need more than standard OT1 encoded CM
> fonts, and a few AMS packages.  This has been working perfectly well ever
> since your first distribution back in the previous millenium.

Yes, it has been a while, hasn't it? Anyway, the old stuff still works.
And people can still install TL2003 or TL2004 based TeX from me, but these
now come with simpdftex instead of altpdftex.

> By removing those scripts, the frontend writer wishing to use the scripts
> is forced to either formally require a new version of tetex (gwtex) or
> write complicated instructions in the manual or 'readme', explaining that
> in certain distributions you have to do one thing, and in other
> distributions you have to do some other thing, and it is akward to
> describe
> precisely what versions because there are so many components involved and
> it is not clear which version number you should refer to or where the user
> can find this information.

simpdftex has been available for 1.5 years or so. So most people now have
it. Those that do not can either stay with their old version frontend, use
a newer frontend with an older TeX (and set their prefs), or update TeX as
well as the frontend.

>> Re-introducing a back compatibility script would defeat the object of
>> the
>> transition completely so I am not going to do it.
> Sorry for being stupid, but how does the error message work?  Isn't it a
> script?  Why does this error script not defeat the objective of the
> transition?  Why is it better to have an error script (breaking existing
> functionality) than having the current symlinks?

I though it was unfriendly not to offer a warning so I have made the
transition as smooth as possible. First step: introduce simpdftex, one
year later (now) change altpdf*tex into a warning, next year, the warning
goes away. I could have dropped the alt* stuff now but that would have
been harsh.

> I don't see any problem with the population of the bin/ directory.  Nobody
> ever opens this directory anyway -- we are not talking a polished OSX
> folder where the presence of more than six items would be intimidating!

Computer scientists often go for elegance because they know that in the
long term they will be defeated by complexity if they don't.

Note: last year or the year before, TeX4ht had the same kind of
transition. No warning scripts just bang from multiple scripts to one with
a different syntax.

> Compare with some other famous transitions: you can still write
> \documentstyle{article} in your source file and it will work.  You can
> still say latex in the command line and it will invoke pdflatex with the
> appropriate parameters...  Do these tricks defeat the objective of the
> transitions?

But some stuff stops working. Currently I get help requests for people
using old ways of detecting PDFTeX vs TeX (which do not work anymore with
TL2005). And the changes in fmtutil and friends make up the bulk of
support requests. Changing engine preferences seems to be easy enough.

>> Backwards compatibility is not truly lost.  You can still compile all
>> your old documents, the only thing that has changed is that the
>> convenience script for running tex, dvips and distiller has been renamed
>> and changed its command line interface.  In my book, backwards
>> compatibility is not lost of you still can get the same results even if
>> you have to do different things to get those results.
> Which book?  And which edition?  :-)

Ha, yes, you've got me there. I should spend time on writing my book
instead of maintaining and supporting a TeX redistribution. If I ever
finish it, you will all buy 100 copies for friends, family, work etc.,

Tell you what: I could reintroduce the altpdf* scripts to run the
simpdftex instead but after a warning and a delay of 20 seconds. It would
work, but it would be nasty enough to make people make the move.

I had to seriously rewrite my TeX i-Package scripts because it has to
handle a different mode of TeX configuration tools (the -sys tools) as
well as the older method (for e.g. TL2003 which I also support). I tried
to argue with Thoams Esser for a different approach, but I was too late.
He had already committed himself to the move a while back.

The frontend writers could check if simpdftex is available and otherwise
use altpdftex. That adds to their complexity, but hey, have you ever read
the perl code of the configuration phase of the TeX i-Package? There you
can see what I have to do to remain compatible with 3 versions of TeX on 2
hardware platforms, among other things.

If users do not upgrade TeX and they do not upgrade their frontend, there
is no problem. If they upgrade their frontend, it is the frontend designer
who decides what he supports and how. The same thing happens to me, look
in my TeX i-Package code and you'll still see support for old TeX
distribution layouts long since gone (texmf.macosx) and people having
upgraded over th elast years have generally not noticed what work was done
in the background. Fonrtend designers can handle the changes in their
environment (that is in this case my TeX distribution) however they want
or not of course.

Anyway, thanks for thinking along. Shall I introduce the seriously slowed
down nagging altpdf*tex scripts? I kind of think the idea is humurous, but
maybe my sense of humour is broken.


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