same example as previous, but now with a EncodeJson type class

Main.purs

module Main where
  
import Data.Generic
import Control.Monad.Eff (Eff)
import Control.Monad.Eff.Console (log, CONSOLE)
import Data.Argonaut.Core (Json, stringify)
import Data.Argonaut.Encode.Class (class EncodeJson)
import Data.Argonaut.Generic.Aeson (encodeJson) as A
import Data.Argonaut.Encode (encodeJson)
import Data.Maybe (Maybe(..))
import Prelude (($), Unit)

newtype EmailAddress = EmailAddress String
derive instance genericEmailAddress ∷ Generic EmailAddress

instance encodeEmailAddressJson :: EncodeJson EmailAddress where
  encodeJson = A.encodeJson
  
newtype Email = Email{
  to ∷ EmailAddress
, from ∷ EmailAddress
, subject ∷ Maybe String
, content ∷ Maybe String
}
derive instance genericEmail ∷ Generic Email

instance encodeEmail :: EncodeJson Email where
  encodeJson =  A.encodeJson


newtype BatchEmails = BatchEmails{
  emails :: Array Email
}
derive instance batchBatchEmails ∷ Generic BatchEmails

instance encodeBatchEmails :: EncodeJson BatchEmails where
  encodeJson =  A.encodeJson



aBatchOfEmails :: BatchEmails
aBatchOfEmails = BatchEmails{
  emails : [ 
     Email{
      to : EmailAddress "dustin@gp.com"
    , from: EmailAddress "agustin@gp.com"
    , subject: Nothing
    , content : Just "Hello, World!"
    }
   , Email{
      to : EmailAddress "dustin@gp.com"
    , from: EmailAddress "agustin@gp.com"
    , subject: Just "This is a subject"
    , content : Nothing
  }
  ]
}

anEncodedBatchOfEmails :: Json
anEncodedBatchOfEmails =  A.encodeJson aBatchOfEmails

logToJsonString :: ∀ a eff. EncodeJson a => a -> Eff (console ∷ CONSOLE | eff) Unit
logToJsonString a = log $ stringify (encodeJson a)

main :: ∀ eff . Eff (console ∷ CONSOLE | eff) Unit
main = logToJsonString aBatchOfEmails