[tex-k] dynamically loading \patterns

[A. Komornicki]

Karl, 
You pose an interesting question.  

Correct me if I am wrong, but essentially you are asking to change 
Format properties without building a new Format. (??)
 
At the risk of sounding (less than informed) I would like to pursue your 
idea of changing hyphenation patterns on the fly. My exposure to such 
flexibility is to use the Babel package and rebuild the LaTeX format all 
over again.   

What would happen if a user were to insert the following 
line in their document: 

 \input  plhyph.tex
 
effectively changing the hyphenation pattern from the default to 
in this case Polish. 

Is this even possible ?  Is this correct ?  Will TeX complain ? 
I have never tried it. 
 
regards,
andrew 


At 06:20 AM 3/3/05, you wrote:
>Hello Olaf and all,
>
>How hard would it be to relax the restriction that \patterns can only be
>executed by initex?  E.g., so a TeX document could load replacement
>patterns for a language for that document, instead of having it embedded
>in a format?
>
>Or, looking at it another way, what would be the downside of always
>using initex?  I doubt the initialization speed is an issue these days.
>
>I seem to remember some stuff in tex.web that makes me think it might be
>nontrivial to allow dynamically reloading patterns.  I think wholesale
>replacement for a given \language is more important than being able to
>add patterns.
>
>The reason for this whole idea is that it would be nice to be able to
>improve hyphenation patterns as time goes by, like everything else,
>instead of being stuck with, say, Knuth's 1982 patterns for US English
>for the rest of time.  On the other hand, of course there's a need for
>archived documents to be able to be typeset again as they were.
>
>The thing that makes hyphenation patterns different than style files in
>this regard is that it's relatively easy to get TeX to load different
>style files, if you want some archived snapshot (e.g., put them all in
>the current directory).  But to load different patterns, you have to
>build a new format, which is pretty impractical (version skew,
>unportable, and just plain painful).
>
>So if we could load new patterns dynamically, in the sources, we could,
>say, build latex.fmt with a hypothetical hyphen-en-US-2005.tex, and old
>source files could explicitly input the original hyphen.tex if there was
>a concern for archival typesetting.
>
>Wdyt?
>
>Thanks,
>k