joseki

Overview ¶

Package joseki is a pure Go library for working with RDF, a powerful framework for representing informations as graphs. For more informations about RDF itself, please see https://www.w3.org/TR/rdf11-concepts

Features ¶

Joseki provides the following features to work with RDF :

* Structures to represent and manipulate the RDF model (URIs, Literals, Blank Nodes, Triples, etc).

* RDF Graphs to store data, with several implentations provided.

* A Low level API to query data stored in graphs.

* A High level API to query data using the SPARQL 1.1 query language.

* Query processing using modern techniques such as join ordering or optimized query execution plans.

* Load RDF data stored in files in various formats (N-Triples, Turtle, etc) into any graph.

* Serialize a RDF Graph into various formats.

Getting Started ¶

This package aims to work with RDF graphs, which are composed of RDF Triple {Subject Object Predicate}. Using joseki, you can represent an RDF Triple as followed :

import (
    "github.com/Callidon/joseki/rdf"
    "fmt"
)
subject := rdf.NewURI("http://example.org/book/book1")
predicate := rdf.NewURI("http://purl.org/dc/terms/title")
object := rdf.NewLiteral("Harry Potter and the Order of the Phoenix")
triple := rdf.NewTriple(subject, predicate, object)
fmt.Println(triple)
// Output : {<http://example.org/book/book1> <http://purl.org/dc/terms/title> "Harry Potter and the Order of the Phoenix"}

You can also store your RDF Triples in a RDF Graph, using various type of graphs. Here, we use a Tree Graph to store our triple :

import (
    "github.com/Callidon/joseki/rdf"
    "github.com/Callidon/joseki/graph"
)
subject := rdf.NewURI("http://example.org/book/book1")
predicate := rdf.NewURI("http://purl.org/dc/terms/title")
object := rdf.NewLiteral("Harry Potter and the Order of the Phoenix")
graph := graph.NewTreeGraph()
graph.Add(rdf.NewTriple(subject, predicate, object))

You can also query any triple from a RDF Graph, using a low level API or a SPARQL query.

import (
    "github.com/Callidon/joseki/rdf"
    "github.com/Callidon/joseki/graph"
    "fmt"
)
graph := graph.NewTreeGraph()
// Datas stored in a file can be easily loaded into a graph
graph.LoadFromFile("datas/awesome-books.ttl", "turtle")
// Let's fetch the titles of all the books in our graph !
subject := rdf.NewVariable("title")
predicate := rdf.NewURI("http://www.w3.org/1999/02/22-rdf-syntax-ns#type")
object := rdf.NewURI("https://schema.org/Book")
for bindings := range graph.Filter(subject, predicate, object) {
    fmt.Println(bindings)
}

For more informations about specific features, see the documentation of each subpackage.

Author : Thomas Minier