[xsl] Unparse-text() string contains ascii chars 29, 30 and 31

[andrew welch <andrew.j.welch@xxxxxxxxx>]

I'm trying to process some data that's one long string delimited using
ascii characters 29, 30 and 31 (which are apparently group, record and
unit 'separator characters').

I can get access to the string using unparsed-text(), but when I
attempt to process the string using any of the function eg:

tokenize($str, '')

or

substring-before($str, '')

...the XML parser complains that these aren't legal XML characters
(when the stylesheet itself is parsed).

Is there any way around this?  I can't see how I can process the
string in XSLT without using the characters themselves.

The two alternative's I can see are to use an XMLFilter to turn it
into XML using Java, or to go back to the source to get them to export
their data in a less archaic way...