add DoubleValueBuilder

3 files changed, 51 insertions, 0 deletions

diff --git a/eval/src/vespa/eval/eval/CMakeLists.txt b/eval/src/vespa/eval/eval/CMakeLists.txt
index 84cebe8cfd0..d108c516e73 100644
--- a/eval/src/vespa/eval/eval/CMakeLists.txt
+++ b/eval/src/vespa/eval/eval/CMakeLists.txt
@@ -6,6 +6,7 @@ vespa_add_library(eval_eval OBJECT
     call_nodes.cpp
     compile_tensor_function.cpp
     delete_node.cpp
+    double_value_builder.cpp
     fast_forest.cpp
     function.cpp
     gbdt.cpp
diff --git a/eval/src/vespa/eval/eval/double_value_builder.cpp b/eval/src/vespa/eval/eval/double_value_builder.cpp
new file mode 100644
index 00000000000..b90bf294d9d
--- /dev/null
+++ b/eval/src/vespa/eval/eval/double_value_builder.cpp
@@ -0,0 +1,20 @@
+// Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+
+#include "double_value_builder.h"
+
+namespace vespalib::eval {
+
+DoubleValueBuilder::DoubleValueBuilder(const eval::ValueType &type,
+                                       size_t num_mapped_in,
+                                       size_t subspace_size_in,
+                                       size_t)
+  : _value(0.0)
+{
+        assert(type.is_double());
+        assert(num_mapped_in == 0);
+        assert(subspace_size_in == 1);
+}
+
+DoubleValueBuilder::~DoubleValueBuilder() = default;
+
+}
diff --git a/eval/src/vespa/eval/eval/double_value_builder.h b/eval/src/vespa/eval/eval/double_value_builder.h
new file mode 100644
index 00000000000..27bac1436f9
--- /dev/null
+++ b/eval/src/vespa/eval/eval/double_value_builder.h
@@ -0,0 +1,30 @@
+// Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+
+#pragma once
+
+#include "value.h"
+
+namespace vespalib::eval {
+
+/**
+ * A trivial builder for DoubleValue objects
+ **/
+class DoubleValueBuilder : public ValueBuilder<double>
+{
+private:
+    double _value;
+public:
+    DoubleValueBuilder(const ValueType &type, size_t num_mapped_in,
+                       size_t subspace_size_in, size_t expected_subspaces);
+    ~DoubleValueBuilder() override;
+    ArrayRef<double>
+    add_subspace(const std::vector<vespalib::stringref> &) override {
+        return ArrayRef<double>(&_value, 1);
+    }
+    std::unique_ptr<Value>
+    build(std::unique_ptr<ValueBuilder<double>>) override {
+        return std::make_unique<DoubleValue>(_value);
+    }
+};
+
+} // namespace