The xml::regexp module provides regular expressions for the following xml tokens: basechar, ideographic, letter, digit, extender, combiningchar, namechar, entityref, charref, reference, name, nmtoken, and attvalue.

the definitions of these tokens were taken from the xml spec (extensible markup language 1.0) at http://www.w3.org/tr/rec-xml.

also contains the regular expressions for the following tokens from the xml namespaces spec at http://www.w3.org/tr/rec-xml-names: ncnamechar, ncname, qname, prefix and localpart.