Currently if the input contains invalid syntax (as is, intentionally, the case with several of the XQuery test suite files) The convertor should still produce a valid XQueryX file, but expressing a Query that just consists of a call to error(). The convertor has a parameter that allows an error code to be specified in the case of an error, the xq2xsltext.xsl uses this so that converted test sute files generate expected error calls wherever possible.
xq2xml is a personal project undertaken by David Carlisle (davidc "at" nag "dot" co "dot" uk). It is however distributed with the knowledge of, and from a web site controlled by, my employer NAG Ltd.