[tex-hyphen] International romani - mid-word exclamation mark

[David Gardner]

Greetings hyphenation experts...
I'm trying to get xetex to accept some very very alpha hypenation
patterns for the internaltional Romani alphabet. It seems to get more
complex the more I look at it.
This is basicaly a latin script with diacritics to mark stress and
unusual vowels, θ, ʒ for some cross dialect morpho-phonemic
skulduggery and (to mark vocatives) mid-word exclamation points.  This
latter is my current source of pain.

The position of the exclamation mark can be before or after the
vowel,(e.g. "rromál!len", or "grást!a").  so sometimes it is a good
hyphenation point, but not always.

At the moment initex is moaning about non-letters in the hyphenation
pattern. I presume I need to change the catcode of ! to solve that  -
would that be in the hypenation file, or somewhere else?

But also, is it possible for XeTeX to count ! as a letter when
mid-word and punctuation (so that the spacing rules work) word
finally? Would I need to make it active and do something clever, and
if it is active, does that break hyphenation?

David