apacheGH-1615: Ref evaluation for lateral

afs · Nov 13, 2022 · 7ca9224 · 7ca9224
1 parent f0139f4
commit 7ca9224
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Showing 3 changed files with 25 additions and 15 deletions.
diff --git a/jena-arq/src/main/java/org/apache/jena/sparql/engine/ref/Evaluator.java b/jena-arq/src/main/java/org/apache/jena/sparql/engine/ref/Evaluator.java
@@ -22,6 +22,7 @@
 
 import org.apache.jena.graph.Node;
 import org.apache.jena.query.SortCondition;
+import org.apache.jena.sparql.algebra.Op;
 import org.apache.jena.sparql.algebra.Table;
 import org.apache.jena.sparql.core.BasicPattern;
 import org.apache.jena.sparql.core.TriplePath;
@@ -51,7 +52,7 @@ public interface Evaluator
     public Table diff(Table tableLeft, Table tableRight);
     public Table minus(Table left, Table right);
     public Table union(Table tableLeft, Table tableRight);
-    //public Table lateral(Table left, Op right, List<Var> vars);
+    public Table lateral(Table left, Op right);
     public Table condition(Table left, Table right);
 
     public Table filter(ExprList expressions, Table tableLeft);

diff --git a/jena-arq/src/main/java/org/apache/jena/sparql/engine/ref/EvaluatorDispatch.java b/jena-arq/src/main/java/org/apache/jena/sparql/engine/ref/EvaluatorDispatch.java
@@ -22,7 +22,6 @@
 import java.util.Deque;
 import java.util.Iterator;
 
-import org.apache.jena.atlas.lib.NotImplemented;
 import org.apache.jena.atlas.logging.Log;
 import org.apache.jena.query.ARQ;
 import org.apache.jena.query.QueryExecException;
@@ -203,12 +202,8 @@ public void visit(OpConditional opCond)
     @Override
     public void visit(OpLateral opLateral)
     {
-        if ( true )
-            throw new NotImplemented();
         Table left = eval(opLateral.getLeft());
-        // But right is substitute and eval.
-        //Table table = evaluator.lateral(left, opLateral.getRight(), opLateral.vars());
-        Table table = null;
+        Table table = evaluator.lateral(left, opLateral.getRight());
         push(table);
     }
 

diff --git a/jena-arq/src/main/java/org/apache/jena/sparql/engine/ref/EvaluatorSimple.java b/jena-arq/src/main/java/org/apache/jena/sparql/engine/ref/EvaluatorSimple.java
@@ -26,19 +26,14 @@
 import org.apache.jena.query.ResultSet;
 import org.apache.jena.query.ResultSetFormatter;
 import org.apache.jena.query.SortCondition;
-import org.apache.jena.sparql.algebra.Algebra;
-import org.apache.jena.sparql.algebra.JoinType;
-import org.apache.jena.sparql.algebra.Table;
-import org.apache.jena.sparql.algebra.TableFactory;
+import org.apache.jena.sparql.algebra.*;
 import org.apache.jena.sparql.algebra.table.TableN;
-import org.apache.jena.sparql.core.BasicPattern;
-import org.apache.jena.sparql.core.TriplePath;
-import org.apache.jena.sparql.core.Var;
-import org.apache.jena.sparql.core.VarExprList;
+import org.apache.jena.sparql.core.*;
 import org.apache.jena.sparql.engine.ExecutionContext;
 import org.apache.jena.sparql.engine.QueryIterator;
 import org.apache.jena.sparql.engine.ResultSetStream;
 import org.apache.jena.sparql.engine.binding.Binding;
+import org.apache.jena.sparql.engine.binding.BindingBuilder;
 import org.apache.jena.sparql.engine.iterator.*;
 import org.apache.jena.sparql.engine.main.QC;
 import org.apache.jena.sparql.expr.ExprAggregator;
@@ -174,6 +169,25 @@ public Table condition(Table left, Table right) {
         return left;
     }
 
+    @Override
+    public Table lateral(Table left, Op right) {
+        if ( left.isEmpty() ) {
+            left.close();
+            return TableFactory.createEmpty();
+        }
+        TableN result = new TableN();
+        left.iterator(getExecContext()).forEachRemaining(binding->{
+            Op op = Substitute.substitute(right, binding);
+            Table t = RefEval.eval(this, op);
+            t.iterator(getExecContext()).forEachRemaining(b->{
+                Binding b2 = BindingBuilder.create(binding).addAll(b).build();
+                result.addBinding(b2);
+            });
+        });
+        left.close();
+        return result;
+    }
+
     @Override
     public Table list(Table table) {
         return table;