Revert "Revert "Bratseth/tensor functions 3""

1 files changed, 38 insertions, 0 deletions

diff --git a/vespajlib/src/main/java/com/yahoo/tensor/functions/ConstantTensor.java b/vespajlib/src/main/java/com/yahoo/tensor/functions/ConstantTensor.java
new file mode 100644
index 00000000000..0727579a331
--- /dev/null
+++ b/vespajlib/src/main/java/com/yahoo/tensor/functions/ConstantTensor.java
@@ -0,0 +1,38 @@
+package com.yahoo.tensor.functions;
+
+import com.yahoo.tensor.MapTensor;
+import com.yahoo.tensor.Tensor;
+
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * A function which returns a constant tensor.
+ * 
+ * @author bratseth
+ */
+public class ConstantTensor extends PrimitiveTensorFunction {
+
+    private final Tensor constant;
+    
+    public ConstantTensor(String tensorString) {
+        this.constant = MapTensor.from(tensorString);
+    }
+    
+    public ConstantTensor(Tensor tensor) {
+        this.constant = tensor;
+    }
+
+    @Override
+    public List<TensorFunction> functionArguments() { return Collections.emptyList(); }
+
+    @Override
+    public PrimitiveTensorFunction toPrimitive() { return this; }
+
+    @Override
+    public Tensor evaluate(EvaluationContext context) { return constant; }
+
+    @Override
+    public String toString(ToStringContext context) { return constant.toString(); }
+
+}