1 files changed, 26 insertions, 0 deletions
diff --git a/lm/builder/discount.hh b/lm/builder/discount.hh
new file mode 100644
index 000000000..754fb20db
--- /dev/null
+++ b/lm/builder/discount.hh
@@ -0,0 +1,26 @@
+#ifndef BUILDER_DISCOUNT__
+#define BUILDER_DISCOUNT__
+
+#include <algorithm>
+
+#include <inttypes.h>
+
+namespace lm {
+namespace builder {
+
+struct Discount {
+  float amount[4];
+
+  float Get(uint64_t count) const {
+    return amount[std::min<uint64_t>(count, 3)];
+  }
+
+  float Apply(uint64_t count) const {
+    return static_cast<float>(count) - Get(count);
+  }
+};
+
+} // namespace builder
+} // namespace lm
+
+#endif // BUILDER_DISCOUNT__