I want to migrate some existing JAX-RS search services to FIQL, but since there is no direct mapping from few existing constructs to FIQL's, I need to introduce some special parameters, for example
which match users with role 1 or
$resources = activeDirectory
which match users assigned to the external resource 'activeDirectrory' or
which match users with not-null surname.
I am providing my own implementation of SearchConditionVisitor for server-side translation from FIQL to my existing format but I would also like to provide a builder capable to nicely handle such 'additions' to standard FIQL.