SHACL/ShEx implementation
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README.md

shaclex

Scala implementation of SHEX and SHACL.

This project contains an implementation of SHACL and ShEx

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Introduction

This project contains an implementation of SHACL and ShEx.

Both are implemented in Scala using the same underlying mechanism using a purely functional approach.

The library handles RDF using a simple RDF interface which has 2 implementations, one using Apache Jena and another one using RDF4j, this means that it is possible to use this library to validate RDF models from any of those RDF libraries, as well as from external SPARQL endpoints.

Installation and compilation

The projects uses sbt for compilation as well as Java 1.8.

  • sbt test compiles and runs the tests

Usage

Once compiled, the program can be run as a command line tool. It is possible to run the program inside sbt as:

Validating RDF data with SHACL

Example:

sbt "run --data examples/shacl/good1.ttl 
         --engine ShaClex"

Validating RDF with ShEx

Example:

sbt "run --engine=ShEx 
         --schema examples/shex/good1.shex 
         --schemaFormat ShExC 
         --data examples/shex/good1.ttl"

Validating RDF data through an SPARQL endpoint

The following example validates RDF nodes from wikidata using Gene-wiki ShEx:

sbt "run --endpoint=https://query.wikidata.org/sparql 
         --schemaUrl=https://raw.githubusercontent.com/SuLab/Genewiki-ShEx/master/diseases/wikidata-disease-ontology.shex 
         --shapeMap=examples/shex/wikidata/disease1.shapeMap 
         --schemaFormat=ShExC 
         --engine=ShEx 
         --trigger=ShapeMap 
         --showResult 
         --resultFormat=JSON"

Interactive mode with sbt

It is usually faster to run the sbt command, which opens the interactive sbt shell and inside that shell, execute the different commands.

$ sbt
... several information about loading libraries
sbt> run -d examples/shacl/good1.ttl --engine ShaClex  

Binary mode

The fastest way to run Shaclex is to compile the code and generate a binary. The following command:

$ sbt universal:packageBin
...generates the file...
target/universal/shaclex-N.N.N.zip

which contains the compressed binary code.

Implementation details

  • The engine is based on Monads using the cats library
  • The ShEx compact syntax parser is implemented using the following Antlr grammar (previous versions used Scala Parser Combinators) which is based on this grammar
  • JSON encoding and decoding uses the Json structure defined here and is implemented using Circe

Compatibility tests

The current implementation passes all shacl-core tests. In order to generate the EARL report, run:

$ sbt 
[...]
sbt:shaclex> project shacl 
sbt:shacl> testOnly es.weso.shacl.report.ReportGeneratorCompatTest

We also aim to pass the ShEx test-suite.

In order to run the shex test-suite and generate the EARL report, you can do the following:

sbt
...
sbt:shaclex> project shex
sbt:shex> compat:test

Convert between Schema formats

Shaclex can be used to convert between different schemas. The following example shows how to convert between ShExC to ShExJ:

$ sbt "run --schema examples/shex/good1.shex 
           --schemaFormat ShExC
           --outSchemaFormat ShExJ
           --showSchema"

More information

  • This project is based on ShExcala which was focused on Shape Expressions only.
  • The aim of Shaclex is to support both ShEx and SHACL and to provide conversions between both languages. More information about both languages can be read in the Validating RDF data written by the authors.
  • An online demo based on this library is available at http://rdfshape.weso.es.

Author & contributors

Contributors:

Adopters

Contribution

Contributions are greatly appreciated. Please fork this repository and open a pull request to add more features or submit issues