[tex-hyphen] problems with sanskrit patterns and xetex?

[Jonathan Kew]

On 9 Jun 2009, at 17:17, Arthur Reutenauer wrote:

>> Thanks a lot for reporting and for the explanation. I did not follow
>> Sanskrit pattern changes and I did not try to explore what these
>> characters are and what purpose they serve
>
>  The characters were added to hyph-sa.tex in revision 260, in order to
> follow an addition to Unicode 5.0.  I have to admit I did not test  
> them
> back then.

Just for the record: The reason they caused a problem is that their  
Unicode category is "symbol" rather than "letter", and therefore the  
(auto-generated) file unicode-letters.tex that sets up \catcode and  
(more significantly, here) \lccode values for all the "letters" in  
Unicode does not include these characters.

In general, if for some reason you want to include characters whose  
Unicode category is not Letter (or Combining Mark) in \patterns,  
you'll need to explicitly set their \lccode first.

I don't suppose there will be many cases where people want to include  
"symbol" characters in hyphenation patterns, but there may be  
occasional instances -- such as this.

JK