Adds triple pattern to SPARQL expression

spargebra/src/parser.rs

@@ -1741,7 +1741,8 @@ parser! {
             l:RDFLiteral() { l.into() } /
             l:NumericLiteral() { l.into() } /
             l:BooleanLiteral() { l.into() } /
-            BuiltInCall()
+            BuiltInCall() /
+            TripleExpression()
 
         //[120]
         rule BrackettedExpression() -> Expression = "(" _ e:Expression() _ ")" { e }
@@ -2094,6 +2095,11 @@ parser! {
             t:GraphTerm() { t.into() } /
             t:EmbTP() { t.into() }
 
+        // Extra rule not yet in the spec
+        rule TripleExpression() -> Expression = "<<" _ s:Expression() _ p:Expression() _ o:Expression() _ ">>" {
+            Expression::FunctionCall(Function::Triple, vec![s, p, o])
+        }
+
         //space
         rule _() = quiet! { ([' ' | '\t' | '\n' | '\r'] / comment())* }
 

testsuite/tests/sparql.rs

@@ -151,10 +151,6 @@ fn sparql_star_query_syntax_testsuite() -> Result<()> {
             "https://w3c.github.io/rdf-star/tests/sparql/syntax#sparql-star-update-6",
             "https://w3c.github.io/rdf-star/tests/sparql/syntax#sparql-star-update-7",
             "https://w3c.github.io/rdf-star/tests/sparql/syntax#sparql-star-update-8",
-            // Not covered by grammar yet
-            "https://w3c.github.io/rdf-star/tests/sparql/syntax#sparql-star-expr-1",
-            "https://w3c.github.io/rdf-star/tests/sparql/syntax#sparql-star-expr-2",
-            "https://w3c.github.io/rdf-star/tests/sparql/syntax#sparql-star-expr-6",
         ],
     )
 }