This repository contains the artifacts for a specification that defines an approach to represent composite values (lists and maps, in particular) as literals in RDF data, and to extend SPARQL with features related to such literals. These extensions include
The latest version of the specification document, which includes an informal description of the approach, is published under the following permanent identifier:
We have extended the Java-based RDF programming framework Apache Jena with a complete implementation of all the features defined in the specification. Currently, the source code of this extension can be found in the UnfoldAndFoldWithCompositeValues branch of the hartig/jena fork of the official Jena Github repository. We have create a pull request to contribute this extension to the Jena project.
To try this implementation you currently need to compile the source code first. To this end, clone the aforementioned fork of the Jena repository to your computer, enter the directory with the local copy of the repository, change to the mentioned branch, and compile the project using Maven as described in the Jena documentation. Thereafter, you should be able to use the ARQ command line programs of Jena to run SPARQL queries that use the features defined in the specification.
Alternatively, after cloning the fork and changing to the mentioned branch, you can import the source code into the Eclipse IDE and, then, run the programs within the IDE. For instance, right click on the file jena-cmds/src/main/java/arq/arq.java in the 'Package Explorer' window of Eclipse and select 'Run As'->'Run Configurations ...' in the pop-up menu. Next, in the 'Run Configurations' dialog that appears, go to the 'Arguments' tab, enter the arguments with which you want to start the program (try the --help argument to see which arguments can be used), and then click the 'Apply' button and the 'Run' button. You can also run the tests of our test suite, for which you need to use the file jena-cmds/src/test/java/arq/rdftests.java in the 'Package Explorer' window of Eclipse.
We have also extended the Perl-based RDF programming framework Attean with a complete implementation of the specification. Currently, the source code of this extension can be found in the mutli-value-exprs branch directly within the Attean Github repository, ready to be merged after discussion with the Attean community.
If you have another implementation, let us know!