Turtle (syntax)

In computing, Terse RDF Triple Language (Turtle) is a syntax and file format for expressing data in the Resource Description Framework (RDF) data model. Turtle syntax is similar to that of SPARQL, an RDF query language. It is a common data format for storing RDF data, along with N-Triples, JSON-LD and RDF/XML.

RDF represents information using semantic triples, which comprise a subject, predicate, and object. Each item in the triple is expressed as a Web URI. Turtle provides a way to group three URIs to make a triple, and provides ways to abbreviate such information, for example by factoring out common portions of URIs. For example, information about Huckleberry Finn could be expressed as:

&lt;http://example.org/person/Mark_Twain> &lt;http://example.org/relation/author> &lt;http://example.org/books/Huckleberry_Finn>.

History
Turtle was defined by Dave Beckett as a subset of Tim Berners-Lee and Dan Connolly's Notation3 (N3) language, and a superset of the minimal N-Triples format. Unlike full N3, which has an expressive power that goes much beyond RDF, Turtle can only serialize valid RDF graphs. Turtle is an alternative to RDF/XML, the original syntax and standard for writing RDF. As opposed to RDF/XML, Turtle does not rely on XML and is generally recognized as being more readable and easier to edit manually than its XML counterpart.

SPARQL, the query language for RDF, uses a syntax similar to Turtle for expressing query patterns.

In 2011, a working group of the World Wide Web Consortium (W3C) started working on an updated version of RDF, with the intention of publishing it along with a standardised version of Turtle. This Turtle specification was published as a W3C Recommendation on 25 February 2014.

A significant proportion of RDF toolkits include Turtle parsing and serializing capability. Some examples of such toolkits are Redland, RDF4J, Jena, Python's RDFLib and JavaScript's N3.js.

Example
The following example defines 3 prefixes ("rdf", "dc", and "ex"), and uses them in expressing a statement about the editorship of the RDF/XML document: (Turtle examples are also valid Notation3).

The example encodes an RDF graph made of four triples, which express these facts:


 * The W3C technical report on RDF syntax and grammar has the title RDF/XML Syntax Specification (Revised).
 * That report's editor is a certain individual, who in turn
 * Has full name Dave Beckett.
 * Has a home page at a certain place.

Here are the triples made explicit in N-Triples notation: The MIME type of Turtle is. The character encoding of Turtle content is always UTF-8.

Named graphs
TriG RDF syntax extends Turtle with support for named graphs.