[XeTeX] preventing hyphenation

[Mike Maxwell]

On 2/19/2011 12:13 AM, I wrote:
> In a grammar we're writing, the transcription of a word "xowunʣāy" gets
> hyphenated immediately after the 'x'. I thought I could prevent this by
> adding the command
> \hyphenation{xowunʣāy}
> near the beginning of the file (before the \begin{document} command).
> However, this has no effect; the word still gets hyphenated.
>
> The paragraph of text in the input is
> Applies to nouns (including verbal nouns) and
> adjectives. \pusArabicScript{ښوون(ه)} /xowun(a)/ \emph{teaching};
> \pusArabicScript{ښوونځای} /xowunʣāy/ \emph{schoolhouse}.
> where \pusArabicScript is our command to switch into Arabic script.
>
> Any idea why the \hyphenation{} command is ineffective?

After a great deal of pulling of hair, I think I've found what's 
happening.  I'm recording it here in case it helps anyone (and because 
one aspect of it seems a bit odd, possibly buggy--although it's beyond 
my competence to decide that).

The quick answer is that, given certain packages I was loading, the 
slashes (used in the above as linguistic markers of the phonemic status 
of the transcriptions) are treated as word-forming characters, meaning 
that the \hyphenation{} command needs to include the slashes.

I'm attaching a minimal example after my signature.  The word that 
erroneously hyphenates in the first paragraph despite the 
\hyphenate{xowun} command is "/xowun/".  The second paragraph in the 
minimal example is preceded by \hyphenate{/xowun/} (*with* the slashes), 
and in this paragraph /xowun/ correctly does not hyphenate.  (You can 
ignore the rest of the text in the paragraphs, it's nonsensical and used 
only to force /xowun/ into a position where LaTeX wants to hyphenate it.)

What seems odd to me about this (and possibly indicative of a bug) is 
that the \hyphenate{/xowun/} command only seems to need the slashes 
around "xowun" if I load the 'listings' package; indeed, without the 
'listings' package the command \hyphenate{/xowun/} results in an error 
msg ("Not a letter", referring to the slash).  Why should the 'listings' 
package affect how the "/" character is treated by the \hyphenate command?

As I say, I'm unsure whether this constitutes a bug, and if so, where it 
should be reported.  Furthermore, this is happening with the TexLive 
2009 distro; for various reasons, I don't have the 2010 distro loaded, 
and I don't know whether it would happen there.  I'm open to advice.

I'm also unsure why the 'bibtopic' package needs to be loaded (without 
the 'bibtopic', I get a "Missing \begin{document}" error msg).  This 
package was apparently auto-generated using docstrip, and at least to 
this human it's not humanly readable.
-- 
	Mike Maxwell
	maxwell at umiacs.umd.edu

----------Minimal example follows-----------------
\documentclass[11pt,letterpaper]{report}
\usepackage{fontspec}
\setmainfont{Charis SIL}

%omitting the 'bibtopic' pkg results in "Missing \begin{document}" msg:
\usepackage{bibtopic}
\usepackage{listings}

\begin{document}
%------------Hyphenation:
%List of words not to hyphenate (or to allow hyphens at particular places);
% see http://en.wikibooks.org/wiki/LaTeX/Formatting#Hyphenation for 
documentation.

\hyphenation{xowun}
%First para: /xowun/ is erroneously hyphenated:
A suffix: Now is time for good suffixes to come
Applies to nouns.  /xowun/

\hyphenation{/xowun/}
%Second para: /xowun/ is correctly not hyphenated:
A suffix: Now is time for good suffixes to come
Applies to nouns.  /xowun/

\end{document}