Serialize scalar functions with context

4 files changed, 58 insertions, 19 deletions

diff --git a/vespajlib/abi-spec.json b/vespajlib/abi-spec.json
index 8b87c5dc79f..47b066b15a6 100644
--- a/vespajlib/abi-spec.json
+++ b/vespajlib/abi-spec.json
@@ -1606,6 +1606,7 @@
       "public java.util.List arguments()",
       "public com.yahoo.tensor.functions.TensorFunction withArguments(java.util.List)",
       "public com.yahoo.tensor.functions.PrimitiveTensorFunction toPrimitive()",
+      "public java.lang.String toString(com.yahoo.tensor.functions.ToStringContext)",
       "public static com.yahoo.tensor.functions.DynamicTensor from(com.yahoo.tensor.TensorType, java.util.Map)",
       "public static com.yahoo.tensor.functions.DynamicTensor from(com.yahoo.tensor.TensorType, java.util.List)"
     ],
@@ -1835,6 +1836,23 @@
     ],
     "fields": []
   },
+  "com.yahoo.tensor.functions.ScalarFunction": {
+    "superClass": "java.lang.Object",
+    "interfaces": [
+      "java.util.function.Function"
+    ],
+    "attributes": [
+      "public",
+      "interface",
+      "abstract"
+    ],
+    "methods": [
+      "public abstract java.lang.Double apply(com.yahoo.tensor.evaluation.EvaluationContext)",
+      "public java.lang.String toString(com.yahoo.tensor.functions.ToStringContext)",
+      "public bridge synthetic java.lang.Object apply(java.lang.Object)"
+    ],
+    "fields": []
+  },
   "com.yahoo.tensor.functions.ScalarFunctions$Abs": {
     "superClass": "java.lang.Object",
     "interfaces": [
diff --git a/vespajlib/src/main/java/com/yahoo/tensor/functions/DynamicTensor.java b/vespajlib/src/main/java/com/yahoo/tensor/functions/DynamicTensor.java
index 1154f962a6f..b8b644f8b49 100644
--- a/vespajlib/src/main/java/com/yahoo/tensor/functions/DynamicTensor.java
+++ b/vespajlib/src/main/java/com/yahoo/tensor/functions/DynamicTensor.java
@@ -46,21 +46,28 @@ public abstract class DynamicTensor extends PrimitiveTensorFunction {
 
     TensorType type() { return type; }
 
+    @Override
+    public String toString(ToStringContext context) {
+        return type().toString() + ":" + contentToString(context);
+    }
+
+    abstract String contentToString(ToStringContext context);
+
     /** Creates a dynamic tensor function. The cell addresses must match the type. */
-    public static DynamicTensor from(TensorType type, Map<TensorAddress, Function<EvaluationContext<?> , Double>> cells) {
+    public static DynamicTensor from(TensorType type, Map<TensorAddress, ScalarFunction> cells) {
         return new MappedDynamicTensor(type, cells);
     }
 
     /** Creates a dynamic tensor function for a bound, indexed tensor */
-    public static DynamicTensor from(TensorType type, List<Function<EvaluationContext<?> , Double>> cells) {
+    public static DynamicTensor from(TensorType type, List<ScalarFunction> cells) {
         return new IndexedDynamicTensor(type, cells);
     }
 
     private static class MappedDynamicTensor extends DynamicTensor {
 
-        private final ImmutableMap<TensorAddress, Function<EvaluationContext<?> , Double>> cells;
+        private final ImmutableMap<TensorAddress, ScalarFunction> cells;
 
-        MappedDynamicTensor(TensorType type, Map<TensorAddress, Function<EvaluationContext<?> , Double>> cells) {
+        MappedDynamicTensor(TensorType type, Map<TensorAddress, ScalarFunction> cells) {
             super(type);
             this.cells = ImmutableMap.copyOf(cells);
         }
@@ -74,11 +81,7 @@ public abstract class DynamicTensor extends PrimitiveTensorFunction {
         }
 
         @Override
-        public String toString(ToStringContext context) {
-            return type().toString() + ":" + contentToString();
-        }
-
-        private String contentToString() {
+        String contentToString(ToStringContext context) {
             if (type().dimensions().isEmpty()) {
                 if (cells.isEmpty()) return "{}";
                 return "{" + cells.values().iterator().next() + "}";
@@ -86,7 +89,7 @@ public abstract class DynamicTensor extends PrimitiveTensorFunction {
 
             StringBuilder b = new StringBuilder("{");
             for (var cell : cells.entrySet()) {
-                b.append(cell.getKey().toString(type())).append(":").append(cell.getValue());
+                b.append(cell.getKey().toString(type())).append(":").append(cell.getValue().toString(context));
                 b.append(",");
             }
             if (b.length() > 1)
@@ -100,9 +103,9 @@ public abstract class DynamicTensor extends PrimitiveTensorFunction {
 
     private static class IndexedDynamicTensor extends DynamicTensor {
 
-        private final List<Function<EvaluationContext<?>, Double>> cells;
+        private final List<ScalarFunction> cells;
 
-        IndexedDynamicTensor(TensorType type, List<Function<EvaluationContext<?> , Double>> cells) {
+        IndexedDynamicTensor(TensorType type, List<ScalarFunction> cells) {
             super(type);
             if ( ! type.dimensions().stream().allMatch(d -> d.type() == TensorType.Dimension.Type.indexedBound))
                 throw new IllegalArgumentException("A dynamic tensor can only be created from a list if the type has " +
@@ -119,11 +122,7 @@ public abstract class DynamicTensor extends PrimitiveTensorFunction {
         }
 
         @Override
-        public String toString(ToStringContext context) {
-            return type().toString() + ":" + contentToString();
-        }
-
-        private String contentToString() {
+        String contentToString(ToStringContext context) {
             if (type().dimensions().isEmpty()) {
                 if (cells.isEmpty()) return "{}";
                 return "{" + cells.get(0) + "}";
@@ -133,7 +132,7 @@ public abstract class DynamicTensor extends PrimitiveTensorFunction {
             StringBuilder b = new StringBuilder("{");
             for (var cell : cells) {
                 indexes.next();
-                b.append(indexes.toAddress().toString(type())).append(":").append(cell);
+                b.append(indexes.toAddress().toString(type())).append(":").append(cell.toString(context));
                 b.append(",");
             }
             if (b.length() > 1)
diff --git a/vespajlib/src/main/java/com/yahoo/tensor/functions/ScalarFunction.java b/vespajlib/src/main/java/com/yahoo/tensor/functions/ScalarFunction.java
new file mode 100644
index 00000000000..c6a244b64df
--- /dev/null
+++ b/vespajlib/src/main/java/com/yahoo/tensor/functions/ScalarFunction.java
@@ -0,0 +1,22 @@
+// Copyright 2019 Oath Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.tensor.functions;
+
+import com.yahoo.tensor.evaluation.EvaluationContext;
+
+import java.util.function.Function;
+
+/**
+ * A function which returns a scalar
+ *
+ * @author bratseth
+ */
+public interface ScalarFunction extends Function<EvaluationContext<?>, Double> {
+
+    @Override
+    Double apply(EvaluationContext<?> context);
+
+    default String toString(ToStringContext context) {
+        return toString();
+    }
+
+}
diff --git a/vespajlib/src/test/java/com/yahoo/tensor/functions/DynamicTensorTestCase.java b/vespajlib/src/test/java/com/yahoo/tensor/functions/DynamicTensorTestCase.java
index 474e6200676..925da9d3c89 100644
--- a/vespajlib/src/test/java/com/yahoo/tensor/functions/DynamicTensorTestCase.java
+++ b/vespajlib/src/test/java/com/yahoo/tensor/functions/DynamicTensorTestCase.java
@@ -34,7 +34,7 @@ public class DynamicTensorTestCase {
         assertEquals("tensor(x{}):{{x:a}:5.0}", t2.toString());
     }
 
-    private static class Constant implements Function<EvaluationContext<?>, Double> {
+    private static class Constant implements ScalarFunction {
 
         private final double value;