Hi,
There haven't been lmtx updates for while now but there is a reason for
it. On my machine I have luametatex 2.08 (so we jump number) which is in
terms of typesetting the 20201010 version. That version has some
reorganized internals, most have to do with consistency in the token
interface at the Lua end. Of course there are some new and improved
things too but those will be revealed in articles or manuals or the
development status documents (already on my machine but they need checking).
However, around that date I also decided to play a bit with some pending
features: extended macro definitions and frozen macros. The first has to
do with extensions to the macro definition code. Some are already
present for a while, others have been added. The challenge there is to
make defining macros somewhat more convenient and at the same time get
rid of often too confusing error messages when a user does something bad
with arguments (those foo_bar_whatever kind of things which might look
impressive but often is pretty ugly). Of course that only makes sense
when we keep the current performance: only gain, no pain. But, it also
means that we need to adapt quite some code in order to benefit from it
and when I started doing that one quickly ends up in a chain reaction:
from a dozen files to over 100 and fives times that amount pending. But
it's actually kind of fun (also for users I think). And hopefully
Wolfgang will find my many errors.
In parallel I played with the other feature: some kind of protection
against macro abuse. This is actually related to the above because when
you want to see macros with readable names in error messages, you cannot
protect them with underscores and other ugly tricks that at the same
time make stuff unreadable and ugly. We have a chicken and egg issue there.
Anyway, the reason for this mail is that I want to warn users that the
next lmtx release will use several protection mechanisms. Checking will
for now be off by default but one can bump the level of protection at
runtime. Just to give you an idea: we have primitives that can get a
heavy protection against overload. We also have macro package system
commands and these can get a pretty hard protection too. Commands
defined by users (using \define...) can be treated less strict. Of
course we also have all kind of runtime (temporary) macros that we have
to protect (freeze) but also be able to redefine when we want to (think
of variables). Then we have properties that are not primitives but
nevertheless need the same strong protection, think of predefined
counters, dimensions etc. So, you can imagine that there is some work
involved in getting all that up and running. A side effect of that is
that occasionally I notice some undesired hack or something that needs
attention. The good news is that this probably can be pulled off without
a real hit on performance.
However, one side effect is that when users enable this (off by default)
mechanism the might run into messages (when only warnings are enables)
or errors (when they go for the full package). Now, in order to get this
working well (as intended) I'd like users who then run into issues to
make small examples that we we add to the test suite (unless of course
they decide to fix the style, simply because they figure that they did
something wrong). You're warned.
So, when the next lmtx hits the web, make sure that you keep the old
tree because one never knows where I mess up. I don't know when I'll
upload. After all Wolfgang and I need to come to the conclusion that
it's the way to go.
More later,
Hans
PS. When doing this one runs into quite interesting conceptual issues,
even in a system like context that is rather structured. But this is
also why the final solution needs somewhat more work that one thinks
when one starts with it. A macro language like tex is quite different
from some regular programming language (and making it look like one
doesn't help).
-----------------------------------------------------------------
Hans Hagen | PRAGMA ADE
Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl
-----------------------------------------------------------------
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the
Wiki!
maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage : http://www.pragma-ade.nl / http://context.aanhet.net
archive : https://bitbucket.org/phg/context-mirror/commits/
wiki : http://contextgarden.net
___________________________________________________________________________________
