Deduce correct concat type

3 files changed, 59 insertions, 3 deletions

diff --git a/vespajlib/src/main/java/com/yahoo/lang/MutableLong.java b/vespajlib/src/main/java/com/yahoo/lang/MutableLong.java
new file mode 100644
index 00000000000..e0e4a0828a9
--- /dev/null
+++ b/vespajlib/src/main/java/com/yahoo/lang/MutableLong.java
@@ -0,0 +1,33 @@
+// Copyright 2018 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.lang;
+
+/**
+ * A mutable long
+ *
+ * @author bratseth
+ */
+public class MutableLong {
+
+    private long value;
+
+    public MutableLong(long value) {
+        this.value = value;
+    }
+
+    public long get() { return value; }
+
+    public void set(long value) { this.value = value; }
+
+    /** Adds the increment to the current value and returns the resulting value */
+    public long add(long increment) {
+        value += increment;
+        return value;
+    }
+
+    /** Adds the increment to the current value and returns the resulting value */
+    public long subtract(long increment) {
+        value -= increment;
+        return value;
+    }
+
+}
diff --git a/vespajlib/src/main/java/com/yahoo/tensor/TensorType.java b/vespajlib/src/main/java/com/yahoo/tensor/TensorType.java
index 14cd3e70866..bf1825446e4 100644
--- a/vespajlib/src/main/java/com/yahoo/tensor/TensorType.java
+++ b/vespajlib/src/main/java/com/yahoo/tensor/TensorType.java
@@ -77,6 +77,13 @@ public class TensorType {
         return Optional.empty();
     }
 
+    /* Returns the bound of this dimension if it is present and bound in this, empty otherwise */
+    public Optional<Long> sizeOfDimension(String dimension) {
+        Optional<Dimension> d = dimension(dimension);
+        if ( ! d.isPresent()) return Optional.empty();
+        return d.get().size();
+    }
+
     /**
      * Returns whether this type can be assigned to the given type,
      * i.e if the given type is a generalization of this type.
diff --git a/vespajlib/src/main/java/com/yahoo/tensor/functions/Concat.java b/vespajlib/src/main/java/com/yahoo/tensor/functions/Concat.java
index a073053bec8..13e7c136feb 100644
--- a/vespajlib/src/main/java/com/yahoo/tensor/functions/Concat.java
+++ b/vespajlib/src/main/java/com/yahoo/tensor/functions/Concat.java
@@ -3,6 +3,8 @@ package com.yahoo.tensor.functions;
 
 import com.google.common.annotations.Beta;
 import com.google.common.collect.ImmutableList;
+import com.yahoo.lang.MutableInteger;
+import com.yahoo.lang.MutableLong;
 import com.yahoo.tensor.DimensionSizes;
 import com.yahoo.tensor.IndexedTensor;
 import com.yahoo.tensor.Tensor;
@@ -66,13 +68,27 @@ public class Concat extends PrimitiveTensorFunction {
 
     /** Returns the type resulting from concatenating a and b */
     private TensorType type(TensorType a, TensorType b) {
+        // TODO: Fail if concat dimension is present but not indexed in a or b
         TensorType.Builder builder = new TensorType.Builder(a, b);
-        if (builder.getDimension(dimension).get().size().isPresent()) // both types have size: correct to concat size
-            builder.set(TensorType.Dimension.indexed(dimension, a.dimension(dimension).get().size().get() +
-                                                                b.dimension(dimension).get().size().get()));
+        if ( ! unboundIn(a, dimension) && ! unboundIn(b, dimension)) {
+            builder.set(TensorType.Dimension.indexed(dimension, a.sizeOfDimension(dimension).orElse(1L) +
+                                                                b.sizeOfDimension(dimension).orElse(1L)));
+            /*
+            MutableLong concatSize = new MutableLong(0);
+            a.sizeOfDimension(dimension).ifPresent(concatSize::add);
+            b.sizeOfDimension(dimension).ifPresent(concatSize::add);
+                builder.set(TensorType.Dimension.indexed(dimension, concatSize.get()));
+                */
+        }
         return builder.build();
     }
 
+    /** Returns true if this dimension is present and unbound */
+    private boolean unboundIn(TensorType type, String dimensionName) {
+        Optional<TensorType.Dimension> dimension = type.dimension(dimensionName);
+        return dimension.isPresent() && ! dimension.get().size().isPresent();
+    }
+
     @Override
     public <NAMETYPE extends TypeContext.Name> Tensor evaluate(EvaluationContext<NAMETYPE> context) {
         Tensor a = argumentA.evaluate(context);