Fixes TriG serialization

lib/oxrdf/src/triple.rs

@@ -1184,7 +1184,7 @@ impl<'a> QuadRef<'a> {
 impl fmt::Display for QuadRef<'_> {
     #[inline]
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        if self.graph_name == GraphNameRef::DefaultGraph {
+        if self.graph_name.is_default_graph() {
             write!(f, "{} {} {}", self.subject, self.predicate, self.object)
         } else {
             write!(

lib/src/io/write.rs

@@ -236,16 +236,16 @@ impl<W: Write> QuadWriter<W> {
                 writeln!(writer, "{quad} .")?;
             }
             QuadWriterKind::TriG(writer) => {
-                if quad.graph_name == GraphNameRef::DefaultGraph {
+                if quad.graph_name.is_default_graph() {
+                    writeln!(writer, "{} .", TripleRef::from(quad))
+                } else {
                     writeln!(
                         writer,
-                        "GRAPH {} {{ {} }}",
+                        "{} {{ {} }}",
                         quad.graph_name,
                         TripleRef::from(quad)
-                    )?;
-                } else {
-                    writeln!(writer, "{quad} .")?;
-                }
+                    )
+                }?;
             }
         }
         Ok(())

python/tests/test_io.py

@@ -8,6 +8,12 @@ from pyoxigraph import *
 EXAMPLE_TRIPLE = Triple(
     NamedNode("http://example.com/foo"), NamedNode("http://example.com/p"), Literal("1")
 )
+EXAMPLE_QUAD = Quad(
+    NamedNode("http://example.com/foo"),
+    NamedNode("http://example.com/p"),
+    Literal("1"),
+    NamedNode("http://example.com/g"),
+)
 
 
 class TestParse(unittest.TestCase):
@@ -53,6 +59,18 @@ class TestParse(unittest.TestCase):
             with TemporaryFile("wb") as fp:
                 list(parse(fp, mime_type="application/n-triples"))
 
+    def test_parse_quad(self) -> None:
+        self.assertEqual(
+            list(
+                parse(
+                    StringIO('<g> { <foo> <p> "1" }'),
+                    "application/trig",
+                    base_iri="http://example.com/",
+                )
+            ),
+            [EXAMPLE_QUAD],
+        )
+
 
 class TestSerialize(unittest.TestCase):
     def test_serialize_to_bytes_io(self) -> None:
@@ -74,3 +92,11 @@ class TestSerialize(unittest.TestCase):
         with self.assertRaises(UnsupportedOperation) as _:
             with TemporaryFile("rb") as fp:
                 serialize([EXAMPLE_TRIPLE], fp, "text/turtle")
+
+    def test_serialize_quad(self) -> None:
+        output = BytesIO()
+        serialize([EXAMPLE_QUAD], output, "application/trig")
+        self.assertEqual(
+            output.getvalue(),
+            b'<http://example.com/g> { <http://example.com/foo> <http://example.com/p> "1" }\n',
+        )

python/tests/test_store.py

@@ -265,6 +265,17 @@ class TestStore(unittest.TestCase):
             b"<http://foo> <http://bar> <http://baz> <http://graph> .\n",
         )
 
+    def test_dump_trig(self) -> None:
+        store = Store()
+        store.add(Quad(foo, bar, baz, graph))
+        store.add(Quad(foo, bar, baz))
+        output = BytesIO()
+        store.dump(output, "application/trig")
+        self.assertEqual(
+            output.getvalue(),
+            b"<http://foo> <http://bar> <http://baz> .\n<http://graph> { <http://foo> <http://bar> <http://baz> }\n",
+        )
+
     def test_dump_file(self) -> None:
         with NamedTemporaryFile(delete=False) as fp:
             file_name = fp.name

testsuite/src/sparql_evaluator.rs

@@ -715,7 +715,7 @@ fn load_graph_to_store<'a>(
     Ok(())
 }
 
-fn load_dataset_to_store<'a>(url: &str, store: &Store) -> Result<()> {
+fn load_dataset_to_store(url: &str, store: &Store) -> Result<()> {
     if let Ok(format) = guess_dataset_format(url) {
         store.load_dataset(read_file(url)?, format, Some(url))
     } else {