Implement update for Powerset

src/Data/Functors/Powerset.hs

@@ -43,6 +43,18 @@ instance RefinementInterface Powerset where
   init :: Powerset -> H1 Powerset -> [Label Powerset] -> Weight Powerset
   init _ _ = (0, ) . length
 
+  update :: Powerset -> [Label Powerset] -> Weight Powerset
+         -> (Weight Powerset, H3 Powerset, Weight Powerset)
+  update _ labels (toRest, toC) =
+    let
+      toS = length labels
+      toCwithoutS = toC - toS
+      weightToS = (toRest + toCwithoutS, toS)
+      h3 = (toRest > 0, toCwithoutS > 0, toS > 0)
+      weightToCwithoutS = (toRest + toS, toCwithoutS)
+    in
+      (weightToS, h3, weightToCwithoutS)
+
 powerset :: RefinableFunctor
 powerset = RefinableFunctor
   { name = "Powerset"