User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.7)
            Gecko/20100120 Shredder/3.0.1
MIME-Version: 1.0
References: <4B727378.8060704@morningstar2.co.uk>                              
            <4B729944.5050308@residenset.net>                                 
            <OFD3BDE8BF.D25CA425-ON802576C6.0043FFAD-802576C6.0043FFAE@mcs-notes1.open.ac.uk>                          
            <4B72B36E.6010401@morningstar2.co.uk>                              
            <OF7A9BB41F.2FC253BE-ON802576C6.005B33FC-802576C6.005B340D@mcs-notes1.open.ac.uk>                          
            <4B730157.5060605@morningstar2.co.uk>                              
            <i7zl3gu98t.fsf@hilbert.math.albany.edu>                           
            <D9F0CF2E-DF59-4056-8A59-DED25B9FE3F2@yahoo.de>                    
            <08431600-FDE2-4002-8A22-81CDD6AF300B@gmail.com>                   
            <e7fba2611002120710m64364a16j7ba9ca65c998dae@mail.gmail.com>       
            <4B76BEE6.50704@gmx.de> <4B7AAD06.9030001@elzevir.fr>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Message-ID:  <4B7ACC53.1030900@gmx.de>
Date:         Tue, 16 Feb 2010 17:48:19 +0100
Reply-To: Mailing list for the LaTeX3 project
              <LATEX-L@listserv.uni-heidelberg.de>
Sender: Mailing list for the LaTeX3 project <LATEX-L@listserv.uni-heidelberg.de>
From: Arno Trautmann <Arno.Trautmann@GMX.DE>
Subject: Re: LaTeX3 8-bit only?
To: LATEX-L@listserv.uni-heidelberg.de
In-Reply-To:  <4B7AAD06.9030001@elzevir.fr>
Precedence: list
Status: R

Manuel Pégourié-Gonnard wrote:
> Arno Trautmann a écrit :
>> It will not be used anymore if there is a more comfortable, maybe
>> faster, and at all ”better“ engine. LuaTeX seems to be this (not faster,
>> but the rest …) so I am using LuaTeX already for production of (small)
>> documents. It’s annoying however that I have to load packages to use it
>> (fontspec etc.) – it would be great to have this implemented in the
>> kernel which is only possible by fully setting on luaTeX.
>>
> I disagree on one point: fully setting on LuaTeX is not the only way. One could
> imagine an architecture like that:
> 
> - the very core of the kernel using only features common to pdfTeX, XeTeX and
> LuaTeX (perhaps with some emulation, such as implementing pdfstrcmp in Lua).
> Mostly as it is now, I believe, but replacing e-TeX with the least common
> denominator of the 3 modern engine: I don't see the point in sticking to e-TeX).

And I don’t see the point in sticking to pdfTeX. Is there a good reason
for this? Would one use pdfTeX if there would be a stable luaTeX?
Regarding XeTeX, it depends on your question below.

>>From the user point of view, no need to load any package, everything is in the
> kernel. Then if you say "latex3 --pdftex" you have a certain set of features
> available, but perhaps a better level of portability, and "latex3 --xetex" or
> "latex3 --luatex" gives you access to another features/portability tradeoff.

That sounds ok for me. Maybe saying that latex3 defaults to luatex so
the user doesn’t have to learn about the engines. If one needs special
support for something, he can use the switches.

> Disclaimer: I'm not saying this is what should be done. As a matter of fact, I
> do not (yet ?) have a clear opinion about how latex3 should handle the engine
> question. I'm just saying this is an option that may be worth considering.
> 
> (I also think that "native" (whatever it means) support for modern engines would
> be a big plus in the adoption of latex3 as a successor to the well-established
> latex2e.)

I even think it’s not only a plus but necessarity.

>>> In practical terms there will be some sort of latex3[.exe] program
>>> provided by TeX distributions to compile documents in LaTeX3 format.
>>> It might as well point to LuaTeX engine and no one will know any
>>> better.
>>
> I'd like to hear good arguments for not doing so. Is there any reason to think
> that LuaTeX will not be as good as XeTeX at some point?

I’d very interested in the answer to this. I don’t know about luaTeX,
but XeTeX provides the very usefull character classes which can be used
in \XeTeXinterchartoks. Is there anything comparable in luaTeX?

> Any fear it doesn't become stable before LaTeX3 is?

Comparing the develompent time of luaTeX vs. LaTeX3: No.

cheers
Arno