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 }"""