Re: waiting for mswincontext / injecting

[Wolfgang Schuster <schuster.wolfgang@googlemail.com>]

On Sat, 22 Sep 2007 12:34:10 +0200
Hans Hagen <pragma@wxs.nl> wrote:

> Wolfgang Schuster wrote:
> 
> > Version 0.997 of XeTeX introduced a new concept to assign every
> > character a class value. You can define rules what should happen if you
> > switch for example from class 1 to class 2 and another one if you do
> > the same in reverse order. The commands for this action are saved in
> > token register and came into action if this class switch appear in the
> > document.
> 
> ok, i remember jonathan talking about it at bachotek
> 
> > the unicode-letters file from XeTeX define a class for quotation,
> > punctutation ... in CJK and another one for the other CJK characters
> > and define spacing and linebreaking between normal characters and
> > punctuation now by the class number (you did something similiar in your
> > chinese module but used active characters instead).
> 
> the problem with such mechanisms is limited options for lookahead and 
> look back
> 
> > The XeTeX reference manual has a simple example of this concept on page
> > 10 and 11.
> > 
> > http://tug.ctan.org/info/xetexref/XeTeX-reference.pdf
> > 
> > can't  this be done in LuaTeX with nodes (or what you mentioned for
> > your color modell) or something similar.
> 
> injecting tokens into the nodelist is no option, since at that stage 
> tokenization already has been done; so it should happen earlier, during 
> tokenization, which can be kind of messy, because even then we're 
> talking of
> 
> a\beta c -> a\char[beta]c (no further expansion) -> inject expanded 
> stuff before, after each chartoken or \char token -> convert tokens to 
> nodes
> 
> sure, i can implement such an injector (since it's tokens, it should 
> haven in the input stream somehow, operating on node lists is kind of 
> messy in that case because tokens need to be expanded) but we're not 
> going to use that method in mkiv. It's one of those areas where xetex 
> and luatex support differs a lot.

this would be nice because many chinese and japanese fonts have very
ugly characters for normal latin texts and would be nice to choose
another font for them.

The second point is some it often neccesary to choose differents fonts
for arabic, greek ... and this method can used to switch to the
corresponding font without inserting font switching commands in the
text but handle this with character classes.

> > but I am too lazy to rename files or create them always by hand with
> > every update ...
> 
> that's what scripting is fore, after all, format generation in tex 
> engines is not automated at all (one has to manage moving fmt files to 
> the right place anyway)

this mean is should learn a scripting language.

Wolfgang
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