1 files changed, 11 insertions, 0 deletions
diff --git a/extractor/features/is_source_target_singleton.cc b/extractor/features/is_source_target_singleton.cc
new file mode 100644
index 00000000..ec816509
--- /dev/null
+++ b/extractor/features/is_source_target_singleton.cc
@@ -0,0 +1,11 @@
+#include "is_source_target_singleton.h"
+
+#include <cmath>
+
+double IsSourceTargetSingleton::Score(const FeatureContext& context) const {
+  return context.pair_count == 1;
+}
+
+string IsSourceTargetSingleton::GetName() const {
+  return "IsSingletonEF";
+}