This page talks about ''higher-order functions'' introduced with [[XQuery 3.0]]. The BaseX-specific <code>hof</code> module containing some more very usful functions can be found at [[Higher-Order Functions Module]].
Warning: in the new upcoming version of the [http://www.w3.org/TR/xpath-functions-30/#func-filter XQuery Functions and Operators] specification, some function signatures have been changed. All function arguments are now placed last:
=Function Items=