[XeTeX] [tex-hyphen] Hyphenation of polytonic Greek (expressed in Unicode)

[Khaled Hosny]

On Thu, Sep 12, 2013 at 09:17:57PM +0100, Philip Taylor wrote:
> Just to follow up on a thread started on the "TeX-Hyphen" list,
> where does one learn exactly what \XeTeXlinebreaklocale does ?
> TeXdoc XeTeX tells me :
> 
> > \XeTeXlinebreaklocale ‹Locale ID›
> > Defines how to break lines for multilingual text.
> 
> but having read that, I am no wiser than I was before,
> except that I now know that \XeTeXlinebreaklocale exists ...

Some writing systems do not use spaces to separate words, so TeX’s
normal line breaking algorithm will fail. \XeTeXlinebreaklocale
instructs XeTeX to break the lines based on the rule of those writing
systems.

‹Locale ID› should be the ISO code of the language in question, though
it seems it will just do The Right Thing™ whatever the value is
(internally this uses the line breaking API of the ICU library and its
documentation is a bit vague, but it seems to calculate the line
breaking position based on the Unicode character properties and the
locale value is simply ignored).

Regards,
Khaled