1 files changed, 4 insertions, 0 deletions
diff --git a/Types.hs b/Types.hs
index 78c59a2..7622f6a 100644
--- a/Types.hs
+++ b/Types.hs
@@ -64,6 +64,10 @@ data Activity a = Activity
 	}
 	deriving (Show, Generic)
 
+-- | Used when a value has had its hashes erased for more efficient
+-- transfer over the wire.
+data MissingHashes a = MissingHashes a
+
 instance DataSize a => DataSize (Activity a) where
 	dataSize a = dataSize (activity a) 
 		+ maybe 0 dataSize (prevActivity a)