updateQuantity :: QuantityMap -> CardMap -> CardMap
updateQuantity = flip $ M.foldlWithKey' combine
    where combine c i q = M.adjust (setQuantity q) i c
updateQuantity :: QuantityMap -> CardMap -> CardMap
updateQuantity = flip $ M.foldlWithKey' combine
    where combine c i q = M.adjust (setQuantity q) i c
updateQuantity = flip $ M.foldlWithKey' combine
    where combine c i q = M.adjust (setQuantity q) i c