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Date:         Tue, 4 Aug 2009 13:03:48 +0200
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From: =?ISO-8859-1?Q?Manuel_P=E9gouri=E9-Gonnard?= <mpg@ELZEVIR.FR>
Subject: using expl3 for latex2e packages
To: LATEX-L@LISTSERV.UNI-HEIDELBERG.DE
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Status: R

Hi,

I'm answering to some remarks of Will, but I think this discussion deserves a
new thread...

Will Robertson a écrit :
> I would like to hope that the expl3 code gets to a state such that we
> don't continue to see new packages on CTAN for performing basic
> high-level "stuff". Just the other day we saw boolexpr, and there are
> several string or token comparison packages. And there are several
> looping packages, as well, I think. More famously, etoolbox attempts
> similar goals as expl3 in a more familiar (but IMHO sometimes more
> cryptic) way.
>
> I'm certainly not saying that the authors of such packages shouldn't be
> doing what they're doing, but if it's doubling development time for
> their other packages (which perform actual tasks, rather than
> nuts'n'bolts) then it would be nice to consolidate some of this material.
>
As a package author, I could be tempted to use the expl3 "toolkit" and
"philosophy" (naming conventions) right now for my new packages, but my main
concern is the following: is expl3 stable enough for using it in production
packages? Though I try to keep informed, I must admit I don't feel so sure.

L3news02 states that "The expl3 code is now considered to be much more
stable than it was before". expl3.pdf (section 6 "the *experimental*
distribution") says "the interface will change". OTOH, source3 states that "The
syntax conventions and functions provided are now ready for wider use." Who's
right between expl3 and source3? (I assume source3, but...)

Another point of concern about using expl3 is that probably we still need to use
other l2e packages too, and then the syntax will be a mix and expl3 and l2e
style. I wonder how to handle it (rename the functions I use with expl3-style
names?).

Maybe the l3 team could publish advice on how to use expl3 in l2e packages, and
include clear statements about which level of stability can be expected from
which module (I mean, are newer modules such as l3keyval and l3msg as stable as
more basic modules).

I you feel it's time for expl3 to be more widely used and start becoming the
standard toolkit for LaTeX programming, maybe more communication could help.
More generally, I feel too few people know about the current l3 achievements and
philosophy, and this problem should be addressed. (Of course the l3 news are a
good point in this direction.)

Manuel.

PS: just as there are projects like texworks aiming at "lowering the barrier to
entry" in the TeX world for complete beginners, I think it's important to lower
the barrier to entry in the l3 world for the average (or advanced, to begin
with) l2e package writer.