This library provides a standalone library for the GREL functions in JAVA. FnO function implementation in JAVA.

Examples:

• RMLStreamer: https://github.com/RMLio/RMLStreamer/tree/development/src/main/resources
• RMLmapper: https://github.com/RMLio/rmlmapper-java/tree/master/src/main/resources
• Grel function: https://github.com/FnOio/grel-functions-java

mvn install

Skip tests:

mvn install -DskipTests

Move the jar and functions file next to the RML mapper jar (here in /opt):

cp rmlfunctions.ttl /opt/
cp target/IdsRmlFunctions-v0.0.1-jar-with-dependencies.jar /opt/IdsRmlFunctions.jar

src/main/java/io/fno/grel contains code to actual functions. Note how they currently are all public and static. Their description is taken directly from GREL. These implementations are mapped to FnO descriptions. How these descriptions look like, you can find in src/main/resources/grel_java_mapping.ttl. Using the fno:function predicate, they are linked to Function descriptions. The function descriptions, you can find at http://users.ugent.be/~bjdmeest/function/grel.ttl#.

mvn test

So Integer instead of int, etc.

The Function Handler for the moment only handles Classes, not primitives.