[XeTeX] hyphenating words with hyphen

[Vadim Radionov]

Dear all,

I'm missing this important detail in the manuals: what is the natural
way to get words with hyphen hyphenated in other places than that
hyphen?

I tried

\XeTeXinterchartokenstate 1

\XeTeXcharclass `\- 150
\XeTeXinterchartoks 150 0 = {\nobreak\hskip0pt}
\XeTeXinterchartoks 0 150 = {\hskip0pt}

and it works almost well -- except for, surprisingly, allowing a break
*before* the hyphen.

Thank you in advance,

Vadim