module Example.Applicative where

import Prelude

import Control.Monad.Except (Except, runExcept)
import Data.List.NonEmpty (NonEmptyList)
import Effect (Effect)
import Effect.Console (logShow)
import Example.Util.Value (foreignValue)
import Foreign (Foreign, ForeignError, readNumber)
import Foreign.Index ((!))

data Point = Point Number Number Number

instance showPoint :: Show Point where
  show (Point x y z) = "(Point " <> show [x, y, z] <> ")"

readPoint :: Foreign -> Except (NonEmptyList ForeignError) Point
readPoint value = do
  Point
    <$> (value ! "x" >>= readNumber)
    <*> (value ! "y" >>= readNumber)
    <*> (value ! "z" >>= readNumber)

main :: Effect Unit
main =
  logShow $ runExcept $
    readPoint =<< foreignValue """{ "x": 1, "y": 2, "z": 3 }"""