starter-snake-haskell-1.1.0: src/Battlesnake/Core/Coordinate.hs

{-# LANGUAGE DeriveGeneric #-}

module Battlesnake.Core.Coordinate where

import Data.Aeson
  ( FromJSON (parseJSON)
  , KeyValue ((.=))
  , ToJSON (toEncoding)
  , pairs
  , withObject
  , (.:)
  )
import GHC.Generics

-- | Represents a coordinate on the game board.
data Coordinate = Coordinate
  { coordX :: Integer
  -- ^ The X coordinate (0 indexed, from left to right)
  , coordY :: Integer
  -- ^ The Y coordinate (0 indexed, from bottom to top)
  }
  deriving (Show, Eq, Generic)

instance ToJSON Coordinate where
  toEncoding (Coordinate x y) = pairs ("x" .= x <> "y" .= y)

instance FromJSON Coordinate where
  parseJSON = withObject "Coordinate" $ \v -> Coordinate <$> v .: "x" <*> v .: "y"