Avoid intermediate NegativeNode in the leaf nodes, adding approximately 15-20% extra nodes.

1 files changed, 18 insertions, 0 deletions

diff --git a/searchlib/src/test/java/com/yahoo/searchlib/rankingexpression/transform/SimplifierTestCase.java b/searchlib/src/test/java/com/yahoo/searchlib/rankingexpression/transform/SimplifierTestCase.java
index f7735b4f5ca..c93830abda9 100644
--- a/searchlib/src/test/java/com/yahoo/searchlib/rankingexpression/transform/SimplifierTestCase.java
+++ b/searchlib/src/test/java/com/yahoo/searchlib/rankingexpression/transform/SimplifierTestCase.java
@@ -5,8 +5,11 @@ import com.yahoo.searchlib.rankingexpression.RankingExpression;
 import com.yahoo.searchlib.rankingexpression.evaluation.Context;
 import com.yahoo.searchlib.rankingexpression.evaluation.MapContext;
 import com.yahoo.searchlib.rankingexpression.evaluation.MapTypeContext;
+import com.yahoo.searchlib.rankingexpression.evaluation.Value;
 import com.yahoo.searchlib.rankingexpression.parser.ParseException;
 import com.yahoo.searchlib.rankingexpression.rule.CompositeNode;
+import com.yahoo.searchlib.rankingexpression.rule.ConstantNode;
+import com.yahoo.searchlib.rankingexpression.rule.NegativeNode;
 import org.junit.Test;
 
 import java.util.Collections;
@@ -83,4 +86,19 @@ public class SimplifierTestCase {
         assertEquals("a + (b + c) / 1.0E8", transformed.toString());
     }
 
+    @Test
+    public void testOptimizingNegativeConstants() throws ParseException {
+        Simplifier s = new Simplifier();
+        TransformContext c = new TransformContext(Collections.emptyMap(), new MapTypeContext());
+        assertEquals("-3", s.transform(new RankingExpression("-3"), c).toString());
+        assertEquals("-9.0", s.transform(new RankingExpression("-3 + -6"), c).toString());
+        assertEquals("-a", s.transform(new RankingExpression("-a"), c).toString());
+        assertEquals("-\"a\"", s.transform(new RankingExpression("-'a'"), c).toString());
+
+        RankingExpression r = new RankingExpression(new NegativeNode(new ConstantNode(Value.parse("3"))));
+        assertTrue(r.getRoot() instanceof NegativeNode);
+        r = s.transform(r, c);
+        assertTrue(r.getRoot() instanceof ConstantNode);
+    }
+
 }