[tex-hyphen] ptex-specific patterns

[Karl Berry]

    Akira's email seems to be bouncing (maybe I need to use another one),

fuk... is good, previous jupiter... is bad.

    But I'm still a bit confused about the fact of whether the engine is
    supposed to behave more like 8-bit pdfTeX or more like UTF-8 XeTeX,

As I understand it, it is neither.  It does not support UTF-8.  It does
not support the European 8-bit encodings.  It supports Japanese
encodings (which are multi-byte).

    \def\t{t2a}\ifx\t\Encoding\input hypht2 \fi
    should read hypht2-ptex. 

Right.  Thanks.

    Is there any simple test file & building instructions?

Not that I am aware of.

    [macro testing for pTeX]

Akira previously suggested testing for pTeX using this, instead of
anything about bytes:
\ifx\kanjiskip\undefined

    but here are some observations (tested on TL 2010). 

Thanks for the observations.  If Akira wants to proceed further, that is
fine with me.  As far as I'm concerned, we do not need to settle this
for TL 2010, and (as I said before) I would just as soon not.  There is
no harm in ptex living in its own universe for a while.

k