Add support for parsing N-Quads

CHANGELOG.md

@@ -1,7 +1,7 @@
 ## unreleased
 
 ### Added
-- Oxigraph native parsers for N-Triples, Turtle and RDF/XML.
+- Oxigraph native parsers for N-Triples, Turtle, RDF/XML and N-Quads.
 
 ### Improved
 - Restructured a code based to account for further additions to the codebase.

oxrdflib/_converter.py

@@ -122,6 +122,8 @@ def rdflib_to_mime_type(rdflib_type: str) -> str:
         return "application/rdf+xml"
     if rdflib_type == "trig":
         return "application/trig"
+    if rdflib_type == "nquads":
+        return "application/n-quads"
     if rdflib_type == "trix":
         return "application/trix"
     raise ValueError(f"Unsupported rdflib type: {rdflib_type}")
@@ -135,4 +137,6 @@ def ox_to_rdflib_type(ox_format: str) -> str:
         return "nt"
     if ox_format == "ox-xml":
         return "xml"
+    if ox_format in ("ox-nquads", "ox-nq"):
+        return "nquads"
     raise ValueError(f"Unsupported Oxigraph type: {ox_format}")

oxrdflib/parser.py

@@ -1,7 +1,7 @@
 import warnings
 from typing import Any, Optional
 
-from rdflib import ConjunctiveGraph, Graph
+from rdflib import Graph
 from rdflib.exceptions import ParserError
 from rdflib.parser import (
     FileInputSource,
@@ -47,6 +47,7 @@ def parse(
 
         else:
             base_iri = sink.absolutize(source.getPublicId() or source.getSystemId() or "")
+            graph_identifier = to_ox(sink.identifier) if format not in ("ox-nq", "ox-nquads") else None
 
             if isinstance(source, FileInputSource):
                 input = source.file
@@ -60,14 +61,14 @@ def parse(
                     input,
                     rdflib_to_mime_type(ox_to_rdflib_type(format)),
                     base_iri=base_iri,
-                    to_graph=to_ox(sink.identifier),
+                    to_graph=graph_identifier,
                 )
             else:
                 sink.store._inner.bulk_load(
                     input,
                     rdflib_to_mime_type(ox_to_rdflib_type(format)),
                     base_iri=base_iri,
-                    to_graph=to_ox(sink.identifier),
+                    to_graph=graph_identifier,
                 )
 
 
@@ -98,7 +99,7 @@ def parse(
 class OxigraphRdfXmlParser(OxigraphParser):
     def parse(
         self,
-        source: FileInputSource,
+        source: InputSource,
         sink: Graph,
         format: str = "ox-xml",
         encoding: Optional[str] = None,
@@ -111,12 +112,12 @@ class OxigraphNQuadsParser(OxigraphParser):
     def parse(
         self,
         source: InputSource,
-        sink: ConjunctiveGraph,
-        format: str,
+        sink: Graph,
+        format: str = "ox-nquads",
         encoding: Optional[str] = None,
         **kwargs: Any,
     ) -> None:
-        raise NotImplementedError("N-Quads is not supported yet")
+        super().parse(source, sink, format, encoding, **kwargs)
 
 
 class OxigraphTriGParser(OxigraphParser):

pyproject.toml

@@ -41,6 +41,8 @@ ox-ttl = "oxrdflib.parser:OxigraphTurtleParser"
 ox-ntriples = "oxrdflib.parser:OxigraphNTriplesParser"
 ox-nt = "oxrdflib.parser:OxigraphNTriplesParser"
 ox-xml = "oxrdflib.parser:OxigraphRdfXmlParser"
+ox-nquads = "oxrdflib.parser:OxigraphNQuadsParser"
+ox-nq = "oxrdflib.parser:OxigraphNQuadsParser"
 
 
 [project.urls]

tests/data/test.nq

@@ -0,0 +1,6 @@
+<http://example.org/stuff/1.0/document> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://xmlns.com/foaf/0.1/Document> <http://example.com/graph1> .
+<http://example.org/stuff/1.0/document> <http://xmlns.com/foaf/0.1/title> "Example Document" <http://example.com/graph1> .
+<http://example.org/stuff/1.0/document> <http://xmlns.com/foaf/0.1/creator> <http://example.org/stuff/1.0/creator> <http://example.com/graph1> .
+<http://example.org/stuff/1.0/creator> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://xmlns.com/foaf/0.1/Person> <http://example.com/graph1> .
+<http://example.org/stuff/1.0/creator> <http://xmlns.com/foaf/0.1/name> "John Doe" <http://example.com/graph1> .
+<http://example.org/stuff/1.0/creator> <http://xmlns.com/foaf/0.1/mbox> <mailto:[email protected]> <http://example.com/graph1> .

tests/test_parser.py

@@ -6,6 +6,12 @@
 
 _TEST_DIR = Path(__file__).resolve().parent
 
+_NAMEDGRAPH_QUERY = """SELECT DISTINCT ?g WHERE {
+  GRAPH ?g {
+    ?s ?p ?o .
+  }
+}"""
+
 
 class TestGraphParsing(unittest.TestCase):
     def test_parsing_ox_turtle_bulk_load(self):
@@ -127,6 +133,18 @@ def test_parsing_ox_rdfxml_fallback(self):
         )
         self.assertEqual(len(graph), 6)
 
+    def test_parsing_ox_nquads_bulk_load(self):
+        graph = rdflib.Dataset(store="Oxigraph")
+        graph.parse(_TEST_DIR / "data/test.nq", format="ox-nquads", transactional=False)
+        self.assertEqual(len(graph), 6)
+        self.assertEqual(len(graph.query(_NAMEDGRAPH_QUERY)), 1)
+
+    def test_parsing_ox_nquads_load(self):
+        graph = rdflib.Dataset(store="Oxigraph")
+        graph.parse(_TEST_DIR / "data/test.nq", format="ox-nquads", transactional=True)
+        self.assertEqual(len(graph), 6)
+        self.assertEqual(len(graph.query(_NAMEDGRAPH_QUERY)), 1)
+
 
 if __name__ == "__main__":
     unittest.main()