The EXSLT Regular Expressions package provides functions that allow testing, matching, and replacing text using JavaScript style regular expressions. The namespace for the Regular Expressions package is http://exslt.org/regular-expressions.
regexp:match() performs regular expression matching on a string, returning the submatches found as a result.
regexp:replace() replaces the portions of a string that match a given regular expression with the contents of another string.
regexp:test() tests to see whether a string matches a specified regular expression.