This package contains the code to map XML Schema and XPath regular expressions to a regular expression engine of the underlying Java platform.

Most of the classes implement a regular expression derived from Apache's Jakarta project. The code of Jakarta has been modified so that the regular expressions implement the syntax of XSD/XPath regular expressions.

In addition, there are classes to provide direct access to the native JDK regular expression engine. The flags value ";j" may be used to select this engine. The resulting syntax/semantics will not be an exact match to the XPath definition.

Users should not normally need to use these classes directly.

Earlier versions of Saxon included a translator from XPath regular expressions to Java regular expressions, based on that produced by James Clark. This mechanism is no longer used.