Fix combination bug with small inventories

src/Dodge/Combine.hs

@@ -48,12 +48,10 @@ lookupItemsUsingTrie ((mods,ct,i,n):xs) t = do
     let is = replicate n' (mods,i)
     concatMap (map (first (is ++)) . lookupItemsUsingTrie xs) $ maybeToList (_trieChildren t M.!? (n',ct))
 
-invertListInvMult :: IM.IntMap Item 
-    -> [[(M.Map ModuleSlot ItemModule,CombineType,Int,Int)]]
+invertListInvMult :: IM.IntMap Item -> [[(M.Map ModuleSlot ItemModule,CombineType,Int,Int)]]
 invertListInvMult = powlistUpToN 4 . invertListInv
 
-invertListInv :: IM.IntMap Item 
-    -> [(M.Map ModuleSlot ItemModule,CombineType,Int,Int)]
+invertListInv :: IM.IntMap Item -> [(M.Map ModuleSlot ItemModule,CombineType,Int,Int)]
 invertListInv = IM.foldrWithKey
     (\k it -> ((_itModules it,_itType it, k, itStackAmount it) :) )
     []

src/Dodge/Initialisation.hs

@@ -1,5 +1,7 @@
 module Dodge.Initialisation where
 import Dodge.Default.World
+--import Dodge.Combine
+--import Dodge.Base.You
 --import Dodge.Base
 --import Dodge.Save
 import Dodge.Data
@@ -39,4 +41,5 @@ initialWorld = defaultWorld
     }
 
 testStringInit :: World -> [String]
-testStringInit w = [show $ length $ _magnets w]
+--testStringInit = map (concatMap $ \(_,ct,_,_) -> show ct) . invertListInvMult . yourInv
+testStringInit = const []

src/Multiset.hs

@@ -18,9 +18,19 @@ powlistUpToN' n (x:xs)
 -- there is a (probably) faster SO answer that produces power lists of size
 -- exactly N, but that answer is harder to adapt
 powlistUpToN :: Int -> [a] -> [[a]]
-powlistUpToN n xs = 
+powlistUpToN n xs = concat $ drop (length xs-n) (subseqsBySize xs)
+  where
+    subseqsBySize [] = [[[]]]
+    subseqsBySize (y:ys) =
+        let next = subseqsBySize ys
+        in zipWith (++) ([]:next) (map (map (y:)) next ++ [[]])
+powlistUpToN'' :: Int -> [a] -> [[a]]
+powlistUpToN'' n xs = 
     let l = length xs
-    in if n > l then [] else concat $ drop (l-n) (subseqsBySize xs)
+--    in if n > l then [] else concat $ drop (l-n) (subseqsBySize xs)
+    in if n > l 
+        then concat $ subseqsBySize xs
+        else concat $ drop (l-n) (subseqsBySize xs)
   where
     subseqsBySize [] = [[[]]]
     subseqsBySize (y:ys) =