Introduce type Precedence.

lib/core/src/Cardano/Wallet/Primitive/Types.hs

@@ -150,6 +150,7 @@ module Cardano.Wallet.Primitive.Types
     , StakePoolTicker (..)
 
     -- * Querying
+    , Precedence (..)
     , SortOrder (..)
 
     -- * Ranges
@@ -455,6 +456,17 @@ data WalletBalance = WalletBalance
                                    Queries
 -------------------------------------------------------------------------------}
 
+-- | Indicates relative precedence.
+--
+-- For two 'Precedence' values @a@ and @b@:
+--
+--     * if @a > b@, then @a@ has higher precedence.
+--     * if @a < b@, then @b@ has higher precedence.
+--     * if @a = b@, then @a@ and @b@ have equal precedence.
+--
+newtype Precedence = Precedence { unPrecedence :: Word64 }
+    deriving (Bounded, Enum, Eq, Ord, Show, Read)
+
 -- | Represents a sort order, applicable to the results returned by a query.
 data SortOrder
     = Ascending