1 files changed, 11 insertions, 0 deletions
diff --git a/vespajlib/src/main/java/com/yahoo/data/access/helpers/MatchFeatureData.java b/vespajlib/src/main/java/com/yahoo/data/access/helpers/MatchFeatureData.java
index f7d72ade20d..4f8bd64f85a 100644
--- a/vespajlib/src/main/java/com/yahoo/data/access/helpers/MatchFeatureData.java
+++ b/vespajlib/src/main/java/com/yahoo/data/access/helpers/MatchFeatureData.java
@@ -13,6 +13,7 @@ import java.util.ArrayList;
 import java.util.AbstractMap.SimpleEntry;
 import java.util.List;
 import java.util.Map;
+import java.util.function.Function;
 
 /**
  * MatchFeatureData helps pack match features for hits into
@@ -85,6 +86,16 @@ public class MatchFeatureData {
             }
             return new Value.DoubleValue(doubleValues[index]);
         }
+
+        public HitValue subsetFilter(Function<Hashlet<String,Integer>, Hashlet<String,Integer>> filter) {
+            return new HitValue(filter.apply(hashlet), dataValues, doubleValues);
+        }
+        // used only from subsetFilter() above
+        private HitValue(Hashlet<String,Integer> hashlet, byte[][] dataValues, double[] doubleValues) {
+            this.hashlet = hashlet;
+            this.dataValues = dataValues;
+            this.doubleValues = doubleValues;
+        }
     }
 
     public HitValue addHit() {