In this paper we present rudof, a Rust library for RDF and RDF Data shapes. The library can be used as a command line tool but it can also be invoked from diferent systems. The flexibility of Rust enables the creation of binaries in Windows, Linux and Mac, as well as ofering Python bindings and WebAssembly components. The library supports ShEx and SHACL, as well as other RDF data modeling languages like DCTAP, ofering conversion mechanisms between them. It can also be used to generate UML-like visualizations of those data models.
CEUR ceur-ws.org
With the increasing adoption of RDF data shapes, there is a need for eficient libraries and
tools which can be used to validate and process RDF. ShEx[
The Rust programming language3 ofers some interesting features which are intended to increase safety with static typing while keeping performance competing with other low-level languages. Another advantage of Rust is the possibility of developing Python bindings that allow Python programmers to invoke Rust libraries that have better performance and even the nEvelop-O LGOBE compilation to Web Assembly4, that can interoperate with Javascript code.
In this paper, we present a new library implemented in Rust, called rudof5 which ofers support for both ShEx and SHACL, conversion between diferent data models like DCTAP, generation of UML-like visualizations and RDF data validation. The diferent components of the library are published at crates.io6, the Rust module registry, and the library publishes binary releases in Windows, Linux, and MacOS, as well as Debian packages, Docker images, and Python bindings7.
The library consists of diferent modules which are also published as Rust crates. In order to minimize external dependencies to other libraries, we created a simple RDF trait called SRDF which ofers the basic RDF functionalities required for validation (mainly accessing the neighborhood of a node). We provide two implementations of SRDF, one based on RDF files like Turtle, and another one based on SPARQL, which allows the library to validate RDF graphs obtained either from files or through SPARQL endpoints.
The library defines other crates that contain the abstract syntax tree representation of both ShEx and SHACL called shex_ast and shacl_ast, as well as their corresponding parsers and validators. There is a module called shapes_converter which contains converters between diferent data models like DCTAP to ShEx, ShEx to UML visualizations, etc. A special module is rudof_cli, which implements the command line tool which is later published as a binary called rudof in diferent platforms like Linux, Mac and Windows.
The library already supports the following features8: • Show information about RDF data and convert between diferent formats like Turtle,
NTriples, RDF/XML, etc. • Support for data shapes languages like ShEx and SHACL: show information about shapes and schemas, and validate RDF data to check conformance. • Parsing DCTAP data models and conversion to shapes schemas. As an example, Figure 1a contains a DCTAP file which can be obtained from an spreadsheet in CSV and figure 1b shows the result of converting it to ShEx. • Generating UML visualizations of shapes data models. As an example, Figure 1c shows the UML generated from 1b. • Generating HTML representations of those schemas, which can be useful when the schemas contain a large number of shapes. In these cases, the UML visualizations can be too big and become unusable, while representing each shape in its own web page makes it possible to browse the shapes in the schema. • Obtaining information about the neighborhood of a node in an RDF graph (either incoming or outgoing arcs), which can be useful to create a schema or to debug the validation results. 4https://webassembly.org/ 5https://rudof-project.github.io/rudof/ 6https://crates.io/ 7https://github.com/rudof-project/rudof/releases 8The project Wiki page contains instructions and how-to guides • Other conversions: we are exploring the conversion between ShEx/SHACL and SPARQL as it is a feature that can be useful to create queries based on some shapes.
name birthdate enrolledIn name
true false false true
Repeatable false false true false valueDatatype xsd:string xsd:date xsd:string valueShape Course (a) DCTAP example 1 prefix : <http://example.org/> 2 prefix xsd: <http://www.w3.org/2001/XMLSchema#> 3 :Person { :name xsd:string ; 4 :birthdate xsd:date ? ; 5 :enrolledIn @:Course * } 6 :Course { :name xsd:string } (b) ShEx obtained from DCTAP example conversion :Person :name : xsd:string :birthdate : xsd:date ? :enrolledIn * :Course :name : xsd:string (c) ShEx visualization
Using Rust as an implementation language can improve the performance compared to Java
or Python. Some preliminary benchmarks have been conducted9 to compare the tool against
several state-of-the-art SHACL implementations. As of September 2, 2024, the tool
demonstrates performance improvements in SHACL validation when compared to Apache Jena10
and TopQuadrant11, although it exhibits longer execution times than rdf4j12. In addition to
these SHACL validation benchmarks, the Python bindings provided by rudof can also be used
to compare performance with other Python libraries for SHACL like pySHACL [
10-LUBM rudof 7.8971 rdf4j 1.6447
60.3583
85.7421 pyrudof 39,364.2842 pySHACL 72,227.2940 9https://github.com/weso/shacl-validation-benchmarks 10https://jena.apache.org/ 11https://github.com/TopQuadrant/shacl 12https://rdf4j.org/ 13More details about performance comparisons will be available at the rudof github repository
Although there are several libraries for ShEx, SHACL or DCTAP, most of them are focused on one of those technologies, and do not ofer a common mechanism for conversion between shapes-based data models. The main exception could be the SHaclEX library14 written by the ifrst author of this paper in Scala.
In the Rust ecosystem, Sophia [
Although rudof is still work-in-progress, we consider that it can fill a need in the RDF data
shapes tools Rust ecosystem. The Rust programming language ofers some advantages in terms
of performance and memory safety. It also ofers the possibility to generate binaries for diferent
operating systems like Windows, Linux and Max, as well as Python bindings. We are exploring
the use of the library in WebAssembly17. Our goal is to gradually migrate the code of our
RDFShape playground [