Shape Expressions (ShEx) is a
data model
A data model is an abstract model that organizes elements of data and standardizes how they relate to one another and to the properties of real-world entities. For instance, a data model may specify that the data element representing a car be ...
ling language for validating and describing a
Resource Description Framework
The Resource Description Framework (RDF) is a method to describe and exchange graph data. It was originally designed as a data model for metadata by the World Wide Web Consortium (W3C). It provides a variety of syntax notations and formats, of whi ...
(RDF).
It was proposed at the 2012 RDF Validation Workshop
as a high-level, concise language for RDF validation.
The shapes can be defined in a human-friendly compact syntax called ShExC or using any RDF
serialization formats like
JSON-LD
JSON-LD (JavaScript Object Notation for Linked Data) is a method of encoding linked data using JSON. One goal for JSON-LD was to require as little effort as possible from developers to transform their existing JSON to JSON-LD. JSON-LD allows data ...
or
Turtle
Turtles are reptiles of the order (biology), order Testudines, characterized by a special turtle shell, shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Crypt ...
.
ShEx expressions can be used both to describe RDF and to automatically check the conformance of RDF data.
The syntax of ShEx is similar to
Turtle
Turtles are reptiles of the order (biology), order Testudines, characterized by a special turtle shell, shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Crypt ...
and
SPARQL
SPARQL (pronounced ":wikt:sparkle, sparkle", a recursive acronym for SPARQL Protocol and RDF Query Language) is an RDF query language—that is, a Semantic Query, semantic query language for databases—able to retrieve and manipulate data sto ...
while the semantics is inspired by regular expression languages like
RelaxNG.
Example
PREFIX :
PREFIX schema:
PREFIX xsd:
:Person
The previous example declares that nodes conforming to shape
Person must have one property
schema:name with a string value and zero or more properties
schema:knows whose values must conform with shape
Person.
Implementations
Online playgrounds and demos
ShExSimple Online demo based o
shex.jsrdfshape online demo based o
shaclex
References
Further reading
Specification
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Other
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See also
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SHACL
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Wikidata
Wikidata is a collaboratively edited multilingual knowledge graph hosted by the Wikimedia Foundation. It is a common source of open data that Wikimedia projects such as Wikipedia, and anyone else, are able to use under the CC0 public domain ...
*
XML schema
An XML schema is a description of a type of XML document, typically expressed in terms of constraints on the structure and content of documents of that type, above and beyond the basic syntactical constraints imposed by XML itself. These constrai ...
s
{{Semantic Web
Resource Description Framework
Data modeling languages
Declarative programming languages
RDF data access
Semantic Web
World Wide Web Consortium standards
SPARQL