Code tidy in TransformPattern2Join
diff --git a/jena-arq/src/main/java/org/apache/jena/sparql/algebra/optimize/TransformPattern2Join.java b/jena-arq/src/main/java/org/apache/jena/sparql/algebra/optimize/TransformPattern2Join.java
index 49bed4a..ea5c33f 100644
--- a/jena-arq/src/main/java/org/apache/jena/sparql/algebra/optimize/TransformPattern2Join.java
+++ b/jena-arq/src/main/java/org/apache/jena/sparql/algebra/optimize/TransformPattern2Join.java
@@ -18,75 +18,56 @@
package org.apache.jena.sparql.algebra.optimize;
-import java.util.List ;
-
-import org.apache.jena.graph.Triple ;
-import org.apache.jena.sparql.algebra.Op ;
+import org.apache.jena.graph.Triple;
+import org.apache.jena.sparql.algebra.Op;
import org.apache.jena.sparql.algebra.OpLib;
-import org.apache.jena.sparql.algebra.TransformCopy ;
-import org.apache.jena.sparql.algebra.op.* ;
-import org.apache.jena.sparql.core.BasicPattern ;
-import org.apache.jena.sparql.core.Quad ;
-import org.apache.jena.sparql.core.QuadPattern ;
+import org.apache.jena.sparql.algebra.TransformCopy;
+import org.apache.jena.sparql.algebra.op.*;
+import org.apache.jena.sparql.core.BasicPattern;
+import org.apache.jena.sparql.core.Quad;
+import org.apache.jena.sparql.core.QuadPattern;
-/** Expand to joins of triples and quads. */
-public class TransformPattern2Join extends TransformCopy
-{
- /*
- * Get standard shaped trees?
- * Alternative is hard flattening to (sequence of all the quads, triples)
- */
-
- @Override
- public Op transform(OpBGP opBGP) { return expand(opBGP.getPattern()) ; }
-
- @Override
- public Op transform(OpQuadPattern quadPattern) { return expand(quadPattern.getPattern()) ; }
+/**
+ * Expand basic graph patterns and quad patterns to
+ * joins of {@code (triple)} and {@code (quad)}.
+ */
+public class TransformPattern2Join extends TransformCopy {
+
+ public TransformPattern2Join() {}
@Override
- public Op transform(OpSequence opSeq, List<Op> elts) { return expand(opSeq, elts) ; }
+ public Op transform(OpBGP opBGP) {
+ return expand(opBGP.getPattern());
+ }
-// @Override
-// public Op transform(OpJoin opJoin, Op left, Op right)
-// { return super.transform(opJoin, left, right) ; }
+ @Override
+ public Op transform(OpQuadPattern quadPattern) {
+ return expand(quadPattern.getPattern());
+ }
- private static Op expand(BasicPattern bgp)
- {
+ private static Op expand(BasicPattern bgp) {
if ( bgp.getList().isEmpty() )
- return OpLib.unit() ;
- Op op = null ;
- for ( Triple t : bgp.getList() )
- {
- OpTriple x = new OpTriple(t) ;
- op = join(op, x) ;
+ return OpLib.unit();
+ Op op = null;
+ for ( Triple t : bgp.getList() ) {
+ OpTriple x = new OpTriple(t);
+ op = join(op, x);
}
- return op ;
- }
-
- private static Op expand(QuadPattern quads)
- {
- if ( quads.getList().isEmpty() )
- return OpLib.unit() ;
- Op op = null ;
- for ( Quad q : quads.getList() )
- {
- OpQuad x = new OpQuad(q) ;
- op = join(op, x) ;
- }
- return op ;
- }
-
- private static Op expand(OpSequence opSeq, List<Op> elts)
- {
- Op x = null ;
- // shape choices.
- for ( Op op : elts )
- x = join(x, op) ;
- return x ;
+ return op;
}
- private static Op join(Op left, Op right)
- {
- return OpJoin.createReduce(left, right) ;
- }
+ private static Op expand(QuadPattern quads) {
+ if ( quads.getList().isEmpty() )
+ return OpLib.unit();
+ Op op = null;
+ for ( Quad q : quads.getList() ) {
+ OpQuad x = new OpQuad(q);
+ op = join(op, x);
+ }
+ return op;
+ }
+
+ private static Op join(Op left, Op right) {
+ return OpJoin.createReduce(left, right);
+ }
}
