1 files changed, 24 insertions, 1 deletions
diff --git a/lib/Malodivo/Types/Ministry.hs b/lib/Malodivo/Types/Ministry.hs
index c3e315b..f3878d1 100644
--- a/lib/Malodivo/Types/Ministry.hs
+++ b/lib/Malodivo/Types/Ministry.hs
@@ -18,15 +18,38 @@ Just [Science]
 
 module Malodivo.Types.Ministry
   ( Ministry(..)
+  , MinistryInfo
+  , MinistryLimits
+  , mi2ml
   ) where
 
+import Control.Arrow ((&&&))
 import GHC.Generics (Generic)
 
 import Data.Aeson (FromJSON, ToJSON)
+import qualified Data.HashMap.Strict as HM
+import Data.Hashable (Hashable)
 
 -- | Ministry of the Kingdom of Malodivo.
 data Ministry
   = Defense
   | Science
   | Welfare
-  deriving (Show, Generic, FromJSON, ToJSON)
+  deriving (Eq, Hashable, Show, Generic, FromJSON, ToJSON)
+
+-- | Convenient type. Describes maximum money a ministry can get.
+type MinistryLimits = HM.HashMap Ministry Integer
+
+{-|
+We use this data type instead of 'MinistryLimits' for JSON,
+because maps other than @HashMap Text _@ are hard to decode/encode see
+<https://github.com/bos/aeson/issues/79>.  Anyway, we still have type-checked
+typos-proof structure.
+-}
+data MinistryInfo = MinistryInfo
+  { name :: Ministry
+  , amount :: Integer
+  } deriving (Generic, FromJSON)
+
+mi2ml :: [MinistryInfo] -> MinistryLimits
+mi2ml = HM.fromListWith (+) . map (name &&& amount)