The RegexpTokenFormatter is an alternative to the default Antlion formatter. It allows for using a matched regular expression based on an attribute's value.

Here's an example:

	<repository basedir="${lib}"> <format text="[groupid,commons-(.*),$1]/[groupid]-[version].jar" /> </repository> : <libraryDef policyRef="track"> <lib-entry groupid="commons-lang" version="2.1"/> </library>

Here, the groupid attribute value ("commons-lang") is checked against the regular expression commons-(.*), and the final value used is the match on .*. So, the repository will check this entry for the file ${lib}/lang/commons-lang-2.1.jar.

At the moment, there is no way to escape the end-token character in the token text. This means that if you want to use a regular expression like t-([^\.]*), you would need to change the end-token character using a format statement like:

	<format text="@groupid,t-([^\.]*),$1@.@type@" startToken="@" endToken="@" />