Implements LATERAL join

Follows SPARQL 1.2 SEP 0006. It is behind a sep-0006 feature in spargebra and sparql-smith and enabled by default in oxigraph.

Apache Jena tests are passing.

SEP 0006: https://github.com/w3c/sparql-12/blob/main/SEP/SEP-0006/sep-0006.md

fuzz/Cargo.toml

@@ -11,9 +11,9 @@ cargo-fuzz = true
 [dependencies]
 lazy_static = "1"
 libfuzzer-sys = "0.4"
-spargebra = { path = "../lib/spargebra", features = ["rdf-star"] }
+spargebra = { path = "../lib/spargebra", features = ["rdf-star", "sep-0006"] }
 sparesults = { path = "../lib/sparesults", features = ["rdf-star"] }
-sparql-smith = { path = "../lib/sparql-smith" }
+sparql-smith = { path = "../lib/sparql-smith", features = ["sep-0006"] }
 oxigraph = { path = "../lib" }
 
 [workspace]

lib/Cargo.toml

@@ -39,7 +39,7 @@ lazy_static = "1"
 sysinfo = "0.27"
 oxrdf = { version = "0.1.1", path="oxrdf", features = ["rdf-star", "oxsdatatypes"] }
 oxsdatatypes = { version = "0.1.0", path="oxsdatatypes" }
-spargebra = { version = "0.2.3", path="spargebra", features = ["rdf-star"] }
+spargebra = { version = "0.2.3", path="spargebra", features = ["rdf-star", "sep-0006"] }
 sparesults = { version = "0.1.3", path="sparesults", features = ["rdf-star"] }
 
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]

lib/spargebra/Cargo.toml

@@ -16,6 +16,7 @@ rust-version = "1.60"
 [features]
 default = []
 rdf-star = ["oxrdf/rdf-star"]
+sep-0006 = []
 
 [dependencies]
 peg = "0.8"

lib/spargebra/src/algebra.rs

@@ -527,6 +527,9 @@ pub enum GraphPattern {
         right: Box<Self>,
         expression: Option<Expression>,
     },
+    /// Lateral join i.e. evaluate right for all result row of left
+    #[cfg(feature = "sep-0006")]
+    Lateral { left: Box<Self>, right: Box<Self> },
     /// [Filter](https://www.w3.org/TR/sparql11-query/#defn_algFilter).
     Filter { expr: Expression, inner: Box<Self> },
     /// [Union](https://www.w3.org/TR/sparql11-query/#defn_algUnion).
@@ -629,6 +632,14 @@ impl GraphPattern {
                 }
                 write!(f, ")")
             }
+            #[cfg(feature = "sep-0006")]
+            Self::Lateral { left, right } => {
+                write!(f, "(lateral ")?;
+                left.fmt_sse(f)?;
+                write!(f, " ")?;
+                right.fmt_sse(f)?;
+                write!(f, ")")
+            }
             Self::Filter { expr, inner } => {
                 write!(f, "(filter ")?;
                 expr.fmt_sse(f)?;
@@ -793,17 +804,19 @@ impl fmt::Display for GraphPattern {
                 object,
             } => write!(f, "{subject} {path} {object} ."),
             Self::Join { left, right } => {
-                if matches!(
-                    right.as_ref(),
+                match right.as_ref() {
                     Self::LeftJoin { .. }
                     | Self::Minus { .. }
                     | Self::Extend { .. }
-                        | Self::Filter { .. }
-                ) {
+                    | Self::Filter { .. } => {
                         // The second block might be considered as a modification of the first one.
                         write!(f, "{left} {{ {right} }}")
-                } else {
-                    write!(f, "{left} {right}")
+                    }
+                    #[cfg(feature = "sep-0006")]
+                    Self::Lateral { .. } => {
+                        write!(f, "{left} {{ {right} }}")
+                    }
+                    _ => write!(f, "{left} {right}"),
                 }
             }
             Self::LeftJoin {
@@ -817,6 +830,10 @@ impl fmt::Display for GraphPattern {
                     write!(f, "{left} OPTIONAL {{ {right} }}")
                 }
             }
+            #[cfg(feature = "sep-0006")]
+            Self::Lateral { left, right } => {
+                write!(f, "{left} LATERAL {{ {right} }}")
+            }
             Self::Filter { expr, inner } => {
                 write!(f, "{inner} FILTER({expr})")
             }
@@ -940,6 +957,11 @@ impl GraphPattern {
                 left.lookup_in_scope_variables(callback);
                 right.lookup_in_scope_variables(callback);
             }
+            #[cfg(feature = "sep-0006")]
+            Self::Lateral { left, right } => {
+                left.lookup_in_scope_variables(callback);
+                right.lookup_in_scope_variables(callback);
+            }
             Self::Graph { name, inner } => {
                 if let NamedNodePattern::Variable(ref g) = name {
                     callback(g);

lib/spargebra/src/parser.rs

@@ -360,6 +360,8 @@ impl<F, T: From<F>> From<FocusedTriplePattern<F>> for FocusedTripleOrPathPattern
 #[derive(Eq, PartialEq, Debug, Clone, Hash)]
 enum PartialGraphPattern {
     Optional(GraphPattern, Option<Expression>),
+    #[cfg(feature = "sep-0006")]
+    Lateral(GraphPattern),
     Minus(GraphPattern),
     Bind(Expression, Variable),
     Filter(Expression),
@@ -620,6 +622,67 @@ fn are_variables_bound(expression: &Expression, variables: &HashSet<Variable>) -
     }
 }
 
+/// Called on every variable defined using "AS" or "VALUES"
+#[cfg(feature = "sep-0006")]
+fn add_defined_variables<'a>(pattern: &'a GraphPattern, set: &mut HashSet<&'a Variable>) {
+    match pattern {
+        GraphPattern::Bgp { .. } | GraphPattern::Path { .. } => {}
+        GraphPattern::Join { left, right }
+        | GraphPattern::LeftJoin { left, right, .. }
+        | GraphPattern::Lateral { left, right }
+        | GraphPattern::Union { left, right }
+        | GraphPattern::Minus { left, right } => {
+            add_defined_variables(left, set);
+            add_defined_variables(right, set);
+        }
+        GraphPattern::Graph { inner, .. } => {
+            add_defined_variables(inner, set);
+        }
+        GraphPattern::Extend {
+            inner, variable, ..
+        } => {
+            set.insert(variable);
+            add_defined_variables(inner, set);
+        }
+        GraphPattern::Group {
+            variables,
+            aggregates,
+            inner,
+        } => {
+            for (v, _) in aggregates {
+                set.insert(v);
+            }
+            let mut inner_variables = HashSet::new();
+            add_defined_variables(inner, &mut inner_variables);
+            for v in inner_variables {
+                if variables.contains(v) {
+                    set.insert(v);
+                }
+            }
+        }
+        GraphPattern::Values { variables, .. } => {
+            for v in variables {
+                set.insert(v);
+            }
+        }
+        GraphPattern::Project { variables, inner } => {
+            let mut inner_variables = HashSet::new();
+            add_defined_variables(inner, &mut inner_variables);
+            for v in inner_variables {
+                if variables.contains(v) {
+                    set.insert(v);
+                }
+            }
+        }
+        GraphPattern::Service { inner, .. }
+        | GraphPattern::Filter { inner, .. }
+        | GraphPattern::OrderBy { inner, .. }
+        | GraphPattern::Distinct { inner }
+        | GraphPattern::Reduced { inner }
+        | GraphPattern::Slice { inner, .. } => add_defined_variables(inner, set),
+    }
+}
+
 fn copy_graph(from: impl Into<GraphName>, to: impl Into<GraphNamePattern>) -> GraphUpdateOperation {
     let bgp = GraphPattern::Bgp {
         patterns: vec![TriplePattern::new(
@@ -1355,6 +1418,21 @@ parser! {
                     PartialGraphPattern::Optional(p, f) => {
                         g = GraphPattern::LeftJoin { left: Box::new(g), right: Box::new(p), expression: f }
                     }
+                    #[cfg(feature = "sep-0006")]
+                    PartialGraphPattern::Lateral(p) => {
+                        let mut defined_variables = HashSet::default();
+                        add_defined_variables(&p, &mut defined_variables);
+                        let mut contains = false;
+                        g.on_in_scope_variable(|v| {
+                            if defined_variables.contains(v) {
+                                contains = true;
+                            }
+                        });
+                        if contains {
+                            return Err("An existing variable is overriden in the right side of LATERAL");
+                        }
+                        g = GraphPattern::Lateral { left: Box::new(g), right: Box::new(p) }
+                    }
                     PartialGraphPattern::Minus(p) => {
                         g = GraphPattern::Minus { left: Box::new(g), right: Box::new(p) }
                     }
@@ -1400,7 +1478,7 @@ parser! {
         rule TriplesBlock_inner() -> Vec<TripleOrPathPattern> = _ h:TriplesSameSubjectPath() _ { h }
 
         //[56]
-        rule GraphPatternNotTriples() -> PartialGraphPattern = GroupOrUnionGraphPattern() / OptionalGraphPattern() / MinusGraphPattern() / GraphGraphPattern() / ServiceGraphPattern() / Filter() / Bind() / InlineData()
+        rule GraphPatternNotTriples() -> PartialGraphPattern = GroupOrUnionGraphPattern() / OptionalGraphPattern() / LateralGraphPattern() / MinusGraphPattern() / GraphGraphPattern() / ServiceGraphPattern() / Filter() / Bind() / InlineData()
 
         //[57]
         rule OptionalGraphPattern() -> PartialGraphPattern = i("OPTIONAL") _ p:GroupGraphPattern() {
@@ -1411,6 +1489,11 @@ parser! {
             }
         }
 
+        rule LateralGraphPattern() -> PartialGraphPattern = i("LATERAL") _ p:GroupGraphPattern() {?
+                #[cfg(feature = "sep-0006")]{Ok(PartialGraphPattern::Lateral(p))}
+                #[cfg(not(feature = "sep-0006"))]{Err("The LATERAL modifier is not supported")}
+        }
+
         //[58]
         rule GraphGraphPattern() -> PartialGraphPattern = i("GRAPH") _ name:VarOrIri() _ p:GroupGraphPattern() {
             PartialGraphPattern::Other(GraphPattern::Graph { name, inner: Box::new(p) })

lib/sparql-smith/Cargo.toml

@@ -12,5 +12,9 @@ A SPARQL test cases generator
 """
 edition = "2021"
 
+[features]
+default = []
+sep-0006 = []
+
 [dependencies]
 arbitrary = { version = "1", features = ["derive"] }

lib/sparql-smith/src/lib.rs

@@ -436,6 +436,8 @@ enum GraphPatternNotTriples {
     Filter(Filter),
     Bind(Bind),
     InlineData(InlineData), // TODO: ServiceGraphPattern
+    #[cfg(feature = "sep-0006")]
+    Lateral(LateralGraphPattern),
 }
 
 impl fmt::Display for GraphPatternNotTriples {
@@ -448,6 +450,8 @@ impl fmt::Display for GraphPatternNotTriples {
             Self::Filter(p) => write!(f, "{p}"),
             Self::Bind(p) => write!(f, "{p}"),
             Self::InlineData(p) => write!(f, "{p}"),
+            #[cfg(feature = "sep-0006")]
+            Self::Lateral(p) => write!(f, "{p}"),
         }
     }
 }
@@ -464,6 +468,18 @@ impl fmt::Display for OptionalGraphPattern {
     }
 }
 
+#[derive(Debug, Arbitrary)]
+struct LateralGraphPattern {
+    // []  	LateralGraphPattern	  ::=  	'LATERAL' GroupGraphPattern
+    inner: GroupGraphPattern,
+}
+
+impl fmt::Display for LateralGraphPattern {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, " LATERAL {}", self.inner)
+    }
+}
+
 #[derive(Debug, Arbitrary)]
 struct GraphGraphPattern {
     // [58]  	GraphGraphPattern	  ::=  	'GRAPH' VarOrIri GroupGraphPattern

lib/src/sparql/eval.rs

@@ -492,7 +492,8 @@ impl SimpleEvaluator {
                             current_right: Box::new(empty()),
                         })
                     } else {
-                        Box::new(BadLeftJoinIterator {
+                        Box::new(BadForLoopLeftJoinIterator {
+                            from_tuple: from.clone(),
                             right_evaluator: right.clone(),
                             left_iter: left(from),
                             current_left: None,
@@ -635,16 +636,19 @@ impl SimpleEvaluator {
                 let mapping = mapping.clone();
                 Rc::new(move |from| {
                     let mapping = mapping.clone();
-                    Box::new(
-                        child(EncodedTuple::with_capacity(mapping.len())).filter_map(
-                            move |tuple| {
+                    let mut input_tuple = EncodedTuple::with_capacity(mapping.len());
+                    for (input_key, output_key) in mapping.iter() {
+                        if let Some(value) = from.get(*output_key) {
+                            input_tuple.set(*input_key, value.clone());
+                        }
+                    }
+                    Box::new(child(input_tuple).filter_map(move |tuple| {
                         match tuple {
                             Ok(tuple) => {
                                 let mut output_tuple = from.clone();
                                 for (input_key, output_key) in mapping.iter() {
                                     if let Some(value) = tuple.get(*input_key) {
-                                                if let Some(existing_value) =
-                                                    output_tuple.get(*output_key)
+                                        if let Some(existing_value) = output_tuple.get(*output_key)
                                         {
                                             if existing_value != value {
                                                 return None; // Conflict
@@ -658,9 +662,7 @@ impl SimpleEvaluator {
                             }
                             Err(e) => Some(Err(e)),
                         }
-                            },
-                        ),
-                    )
+                    }))
                 })
             }
             PlanNode::Aggregate {
@@ -2943,27 +2945,6 @@ fn put_variable_value(
     }
 }
 
-fn unbind_variables(binding: &mut EncodedTuple, variables: &[usize]) {
-    for var in variables {
-        binding.unset(*var)
-    }
-}
-
-fn combine_tuples(mut a: EncodedTuple, b: &EncodedTuple, vars: &[usize]) -> Option<EncodedTuple> {
-    for var in vars {
-        if let Some(b_value) = b.get(*var) {
-            if let Some(a_value) = a.get(*var) {
-                if a_value != b_value {
-                    return None;
-                }
-            } else {
-                a.set(*var, b_value.clone());
-            }
-        }
-    }
-    Some(a)
-}
-
 pub fn are_compatible_and_not_disjointed(a: &EncodedTuple, b: &EncodedTuple) -> bool {
     let mut found_intersection = false;
     for (a_value, b_value) in a.iter().zip(b.iter()) {
@@ -3702,7 +3683,8 @@ impl Iterator for ForLoopLeftJoinIterator {
     }
 }
 
-struct BadLeftJoinIterator {
+struct BadForLoopLeftJoinIterator {
+    from_tuple: EncodedTuple,
     right_evaluator: Rc<dyn Fn(EncodedTuple) -> EncodedTuplesIterator>,
     left_iter: EncodedTuplesIterator,
     current_left: Option<EncodedTuple>,
@@ -3710,18 +3692,16 @@ struct BadLeftJoinIterator {
     problem_vars: Rc<Vec<usize>>,
 }
 
-impl Iterator for BadLeftJoinIterator {
+impl Iterator for BadForLoopLeftJoinIterator {
     type Item = Result<EncodedTuple, EvaluationError>;
 
     fn next(&mut self) -> Option<Result<EncodedTuple, EvaluationError>> {
         for right_tuple in &mut self.current_right {
             match right_tuple {
                 Ok(right_tuple) => {
-                    if let Some(combined) = combine_tuples(
-                        right_tuple,
-                        self.current_left.as_ref().unwrap(),
-                        &self.problem_vars,
-                    ) {
+                    if let Some(combined) =
+                        right_tuple.combine_with(self.current_left.as_ref().unwrap())
+                    {
                         return Some(Ok(combined));
                     }
                 }
@@ -3730,15 +3710,19 @@ impl Iterator for BadLeftJoinIterator {
         }
         match self.left_iter.next()? {
             Ok(left_tuple) => {
-                let mut filtered_left = left_tuple.clone();
-                unbind_variables(&mut filtered_left, &self.problem_vars);
-                self.current_right = (self.right_evaluator)(filtered_left);
+                let mut right_input = self.from_tuple.clone();
+                for (var, val) in left_tuple.iter().enumerate() {
+                    if let Some(val) = val {
+                        if !self.problem_vars.contains(&var) {
+                            right_input.set(var, val);
+                        }
+                    }
+                }
+                self.current_right = (self.right_evaluator)(right_input);
                 for right_tuple in &mut self.current_right {
                     match right_tuple {
                         Ok(right_tuple) => {
-                            if let Some(combined) =
-                                combine_tuples(right_tuple, &left_tuple, &self.problem_vars)
-                            {
+                            if let Some(combined) = right_tuple.combine_with(&left_tuple) {
                                 self.current_left = Some(left_tuple);
                                 return Some(Ok(combined));
                             }

lib/src/sparql/plan.rs

@@ -674,12 +674,6 @@ impl EncodedTuple {
         self.inner[index] = Some(value);
     }
 
-    pub fn unset(&mut self, index: usize) {
-        if let Some(v) = self.inner.get_mut(index) {
-            *v = None;
-        }
-    }
-
     pub fn combine_with(&self, other: &Self) -> Option<Self> {
         if self.inner.len() < other.inner.len() {
             let mut result = other.inner.clone();

lib/src/sparql/plan_builder.rs

@@ -133,6 +133,10 @@ impl<'a> PlanBuilder<'a> {
                     }
                 }
             }
+            GraphPattern::Lateral { left, right } => PlanNode::ForLoopJoin {
+                left: Box::new(self.build_for_graph_pattern(left, variables, graph_name)?),
+                right: Box::new(self.build_for_graph_pattern(right, variables, graph_name)?),
+            },
             GraphPattern::Filter { expr, inner } => self.push_filter(
                 Box::new(self.build_for_graph_pattern(inner, variables, graph_name)?),
                 Box::new(self.build_for_expression(expr, variables, graph_name)?),
@@ -1120,8 +1124,11 @@ impl<'a> PlanBuilder<'a> {
                 right.lookup_used_variables(&mut |v| {
                     set.insert(v);
                 });
+                let always_already_bound = left.always_bound_variables();
                 expression.lookup_used_variables(&mut |v| {
+                    if !always_already_bound.contains(&v) {
                         set.insert(v);
+                    }
                 });
             }
             PlanNode::Extend {
@@ -1138,10 +1145,14 @@ impl<'a> PlanBuilder<'a> {
             }
             PlanNode::Sort { child, .. }
             | PlanNode::HashDeduplicate { child }
-            | PlanNode::Reduced { child }
-            | PlanNode::Skip { child, .. }
-            | PlanNode::Limit { child, .. } => {
-                Self::add_left_join_problematic_variables(child, set)
+            | PlanNode::Reduced { child } => {
+                Self::add_left_join_problematic_variables(child, set);
+            }
+            PlanNode::Skip { child, .. } | PlanNode::Limit { child, .. } => {
+                // Any variable might affect arity
+                child.lookup_used_variables(&mut |v| {
+                    set.insert(v);
+                })
             }
             PlanNode::Service { child, silent, .. } => {
                 if *silent {

testsuite/oxigraph-tests/sparql/lateral/basic_input.ttl

@@ -0,0 +1,5 @@
+@prefix ex: <http://example.org/> .
+
+ex:s1 a ex:T ; ex:p 11 , 12 , 13 .
+ex:s2 a ex:T ; ex:p 21 , 22 , 23 .
+ex:s3 a ex:T .

testsuite/oxigraph-tests/sparql/lateral/filter.rq

@@ -0,0 +1,6 @@
+PREFIX ex: <http://example.org/>
+
+SELECT ?s ?o WHERE {
+    VALUES ?s { ex:S }
+    LATERAL { VALUES ?o { ex:O } FILTER(BOUND(?s) && EXISTS { FILTER(BOUND(?s)) }) }
+}

testsuite/oxigraph-tests/sparql/lateral/graph.rq

@@ -0,0 +1,6 @@
+PREFIX ex: <http://example.org/>
+
+SELECT ?s ?o WHERE {
+    VALUES ?s { ex:S }
+    LATERAL { GRAPH ex:G { FILTER(BOUND(?s)) . VALUES ?o { ex:O } } }
+}

testsuite/oxigraph-tests/sparql/lateral/join.rq

@@ -0,0 +1,9 @@
+PREFIX ex: <http://example.org/>
+
+SELECT ?s ?o WHERE {
+    VALUES ?s { ex:S }
+    LATERAL {
+        { VALUES ?o { ex:O } }
+        { FILTER(BOUND(?s) && !BOUND(?o)) }
+    }
+}

testsuite/oxigraph-tests/sparql/lateral/manifest.ttl

@@ -0,0 +1,68 @@
+@prefix rdf:   <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
+@prefix :      <https://github.com/oxigraph/oxigraph/tests/sparql/lateral/manifest#> .
+@prefix rdfs:  <http://www.w3.org/2000/01/rdf-schema#> .
+@prefix mf:    <http://www.w3.org/2001/sw/DataAccess/tests/test-manifest#> .
+@prefix qt:    <http://www.w3.org/2001/sw/DataAccess/tests/test-query#> .
+@prefix ut:    <http://www.w3.org/2009/sparql/tests/test-update#> .
+
+<>  rdf:type mf:Manifest ;
+    rdfs:label "Oxigraph LATERAL feature SPARQL tests" ;
+    mf:entries
+    (
+    :subselect
+    :subselect_inside_optional
+    :subselect_outside_optional
+    :subselect_aggregate
+    :optional
+    :graph
+    :filter
+    :join
+    ) .
+
+:subselect rdf:type mf:QueryEvaluationTest ;
+    mf:name "Basic subselect LATERAL test" ;
+    mf:action
+         [ qt:query  <subselect.rq> ;
+           qt:data   <basic_input.ttl> ] ;
+    mf:result  <subselect.srx> .
+
+:subselect_inside_optional rdf:type mf:QueryEvaluationTest ;
+    mf:name "Basic subselect LATERAL test inside OPTIONAL" ;
+    mf:action
+         [ qt:query  <subselect_inside_optional.rq> ;
+           qt:data   <basic_input.ttl> ] ;
+    mf:result  <subselect_inside_optional.srx> .
+
+:subselect_outside_optional rdf:type mf:QueryEvaluationTest ;
+    mf:name "Basic subselect test inside LATERAL OPTIONAL" ;
+    mf:action
+         [ qt:query  <subselect_outside_optional.rq> ;
+           qt:data   <basic_input.ttl> ] ;
+    mf:result  <subselect_outside_optional.srx> .
+
+:subselect_aggregate rdf:type mf:QueryEvaluationTest ;
+    mf:name "LATERAL test with explicit aggregate" ;
+    mf:action
+         [ qt:query  <subselect_aggregate.rq> ;
+           qt:data   <basic_input.ttl> ] ;
+    mf:result  <subselect_aggregate.srx> .
+
+:optional rdf:type mf:QueryEvaluationTest ;
+    mf:name "LATERAL OPTIONAL test" ;
+    mf:action [ qt:query  <optional.rq> ] ;
+    mf:result  <simple.srx> .
+
+:graph rdf:type mf:QueryEvaluationTest ;
+    mf:name "LATERAL GRAPH test" ;
+    mf:action [ qt:query  <graph.rq> ] ;
+    mf:result  <simple.srx> .
+
+:filter rdf:type mf:QueryEvaluationTest ;
+    mf:name "LATERAL FILTER test" ;
+    mf:action [ qt:query  <filter.rq> ] ;
+    mf:result  <simple.srx> .
+
+:join rdf:type mf:QueryEvaluationTest ;
+    mf:name "join in LATERAL test" ;
+    mf:action [ qt:query  <join.rq> ] ;
+    mf:result  <simple.srx> .

testsuite/oxigraph-tests/sparql/lateral/optional.rq

@@ -0,0 +1,6 @@
+PREFIX ex: <http://example.org/>
+
+SELECT ?s ?o WHERE {
+    VALUES ?s { ex:S }
+    LATERAL { OPTIONAL { FILTER(BOUND(?s)) . VALUES ?o { ex:O } } }
+}

testsuite/oxigraph-tests/sparql/lateral/simple.srx

@@ -0,0 +1,17 @@
+<?xml version="1.0"?>
+<sparql xmlns="http://www.w3.org/2005/sparql-results#">
+  <head>
+    <variable name="s"/>
+    <variable name="o"/>
+  </head>
+  <results>
+    <result>
+      <binding name="s">
+        <uri>http://example.org/S</uri>
+      </binding>
+      <binding name="o">
+        <uri>http://example.org/O</uri>
+      </binding>
+    </result>
+  </results>
+</sparql>

testsuite/oxigraph-tests/sparql/lateral/subselect.rq

@@ -0,0 +1,6 @@
+PREFIX ex: <http://example.org/>
+
+SELECT ?s ?o WHERE {
+    ?s a ex:T.
+    LATERAL {SELECT ?s ?o WHERE { ?s ex:p ?o } ORDER BY ?o LIMIT 2}
+}

testsuite/oxigraph-tests/sparql/lateral/subselect.srx

@@ -0,0 +1,41 @@
+<?xml version="1.0"?>
+<sparql xmlns="http://www.w3.org/2005/sparql-results#">
+  <head>
+    <variable name="s"/>
+    <variable name="o"/>
+  </head>
+  <results>
+    <result>
+      <binding name="s">
+        <uri>http://example.org/s1</uri>
+      </binding>
+      <binding name="o">
+        <literal datatype="http://www.w3.org/2001/XMLSchema#integer">11</literal>
+      </binding>
+    </result>
+    <result>
+      <binding name="s">
+        <uri>http://example.org/s1</uri>
+      </binding>
+      <binding name="o">
+        <literal datatype="http://www.w3.org/2001/XMLSchema#integer">12</literal>
+      </binding>
+    </result>
+    <result>
+      <binding name="s">
+        <uri>http://example.org/s2</uri>
+      </binding>
+      <binding name="o">
+        <literal datatype="http://www.w3.org/2001/XMLSchema#integer">21</literal>
+      </binding>
+    </result>
+    <result>
+      <binding name="s">
+        <uri>http://example.org/s2</uri>
+      </binding>
+      <binding name="o">
+        <literal datatype="http://www.w3.org/2001/XMLSchema#integer">22</literal>
+      </binding>
+    </result>
+  </results>
+</sparql>

testsuite/oxigraph-tests/sparql/lateral/subselect_aggregate.rq

@@ -0,0 +1,6 @@
+PREFIX ex: <http://example.org/>
+
+SELECT ?s ?c WHERE {
+    ?s a ex:T.
+    LATERAL {SELECT ?s (MAX(?o) AS ?c) WHERE { ?s ex:p ?o } GROUP BY ?s}
+}

testsuite/oxigraph-tests/sparql/lateral/subselect_aggregate.srx

@@ -0,0 +1,25 @@
+<?xml version="1.0"?>
+<sparql xmlns="http://www.w3.org/2005/sparql-results#">
+  <head>
+    <variable name="s"/>
+    <variable name="c"/>
+  </head>
+  <results>
+    <result>
+      <binding name="s">
+        <uri>http://example.org/s1</uri>
+      </binding>
+      <binding name="c">
+        <literal datatype="http://www.w3.org/2001/XMLSchema#integer">13</literal>
+      </binding>
+    </result>
+    <result>
+      <binding name="s">
+        <uri>http://example.org/s2</uri>
+      </binding>
+      <binding name="c">
+        <literal datatype="http://www.w3.org/2001/XMLSchema#integer">23</literal>
+      </binding>
+    </result>
+  </results>
+</sparql>

testsuite/oxigraph-tests/sparql/lateral/subselect_inside_optional.rq

@@ -0,0 +1,6 @@
+PREFIX ex: <http://example.org/>
+
+SELECT ?s ?o WHERE {
+    ?s a ex:T.
+    OPTIONAL { LATERAL {SELECT ?s ?o WHERE { ?s ex:p ?o } ORDER BY ?o LIMIT 2} }
+}

testsuite/oxigraph-tests/sparql/lateral/subselect_inside_optional.srx

@@ -0,0 +1,35 @@
+<?xml version="1.0"?>
+<sparql xmlns="http://www.w3.org/2005/sparql-results#">
+  <head>
+    <variable name="s"/>
+    <variable name="o"/>
+  </head>
+  <results>
+    <result>
+      <binding name="s">
+        <uri>http://example.org/s1</uri>
+      </binding>
+      <binding name="o">
+        <literal datatype="http://www.w3.org/2001/XMLSchema#integer">11</literal>
+      </binding>
+    </result>
+    <result>
+      <binding name="s">
+        <uri>http://example.org/s1</uri>
+      </binding>
+      <binding name="o">
+        <literal datatype="http://www.w3.org/2001/XMLSchema#integer">12</literal>
+      </binding>
+    </result>
+    <result>
+      <binding name="s">
+        <uri>http://example.org/s2</uri>
+      </binding>
+    </result>
+    <result>
+      <binding name="s">
+        <uri>http://example.org/s3</uri>
+      </binding>
+    </result>
+  </results>
+</sparql>

testsuite/oxigraph-tests/sparql/lateral/subselect_outside_optional.rq

@@ -0,0 +1,6 @@
+PREFIX ex: <http://example.org/>
+
+SELECT ?s ?o WHERE {
+    ?s a ex:T.
+    LATERAL { OPTIONAL {SELECT ?s ?o WHERE { ?s ex:p ?o } ORDER BY ?o LIMIT 2} }
+}

testsuite/oxigraph-tests/sparql/lateral/subselect_outside_optional.srx

@@ -0,0 +1,46 @@
+<?xml version="1.0"?>
+<sparql xmlns="http://www.w3.org/2005/sparql-results#">
+  <head>
+    <variable name="s"/>
+    <variable name="o"/>
+  </head>
+  <results>
+    <result>
+      <binding name="s">
+        <uri>http://example.org/s1</uri>
+      </binding>
+      <binding name="o">
+        <literal datatype="http://www.w3.org/2001/XMLSchema#integer">11</literal>
+      </binding>
+    </result>
+    <result>
+      <binding name="s">
+        <uri>http://example.org/s1</uri>
+      </binding>
+      <binding name="o">
+        <literal datatype="http://www.w3.org/2001/XMLSchema#integer">12</literal>
+      </binding>
+    </result>
+    <result>
+      <binding name="s">
+        <uri>http://example.org/s2</uri>
+      </binding>
+      <binding name="o">
+        <literal datatype="http://www.w3.org/2001/XMLSchema#integer">21</literal>
+      </binding>
+    </result>
+    <result>
+      <binding name="s">
+        <uri>http://example.org/s2</uri>
+      </binding>
+      <binding name="o">
+        <literal datatype="http://www.w3.org/2001/XMLSchema#integer">22</literal>
+      </binding>
+    </result>
+    <result>
+      <binding name="s">
+        <uri>http://example.org/s3</uri>
+      </binding>
+    </result>
+  </results>
+</sparql>

testsuite/oxigraph-tests/sparql/manifest.ttl

@@ -7,6 +7,7 @@
 
 <>  rdf:type mf:Manifest ;
     rdfs:label "Oxigraph SPARQL tests" ;
+    mf:include ( <lateral/manifest.ttl> ) ;
     mf:entries
     (
     :small_unicode_escape_with_multibytes_char

testsuite/tests/oxigraph.rs

@@ -16,7 +16,12 @@ fn run_testsuite(manifest_urls: Vec<&str>) -> Result<()> {
         }
     }
 
-    assert!(errors.is_empty(), "\n{}\n", errors.join("\n"));
+    assert!(
+        errors.is_empty(),
+        "{} failing tests:\n{}\n",
+        errors.len(),
+        errors.join("\n")
+    );
     Ok(())
 }
 

testsuite/tests/parser.rs

@@ -16,7 +16,12 @@ fn run_testsuite(manifest_url: &str) -> Result<()> {
         }
     }
 
-    assert!(errors.is_empty(), "\n{}\n", errors.join("\n"));
+    assert!(
+        errors.is_empty(),
+        "{} failing tests:\n{}\n",
+        errors.len(),
+        errors.join("\n")
+    );
     Ok(())
 }
 

testsuite/tests/sparql.rs

@@ -18,7 +18,12 @@ fn run_testsuite(manifest_url: &str, ignored_tests: Vec<&str>) -> Result<()> {
         }
     }
 
-    assert!(errors.is_empty(), "\n{}\n", errors.join("\n"));
+    assert!(
+        errors.is_empty(),
+        "{} failing tests:\n{}\n",
+        errors.len(),
+        errors.join("\n")
+    );
     Ok(())
 }