# Package com.complexible.stardog.plan.filter.functions

package com.complexible.stardog.plan.filter.functions
Packaging containing the definition of a Function and all the built-in implementations for strings, dates, etc.

Primarily, the `Function` implementations correspond to some defined XPath function, which is usually noted in the documentation for the function itself. There are a few which are non-XPath functions which are specific to either the SPARQL specification or SWRL. See `XPathFunctions` for an incomplete list of which XPath functions are implemented in Stardog.

Functions available via `FunctionRegistry` can be used as custom SPARQL functions at query time. See `Function` for information on binding new implementations of `Function` at runtime.

Registration of the core Stardog Functions is performed by `SPARQLFunctions`

- Class
  Description
  AbstractFunction
  Abstract stub implementation of a Function.
  Function
  This is the extension point for 17.6 (Extensible Value Testing) of the SPARQL spec.