Using Json for multiple types into an array

MultipleTypes.purs

module MultipleTypes where

import Data.Argonaut.Decode.Combinators ((.?))
import Prelude

import Data.Argonaut.Core (Json, caseJson)
import Data.Argonaut.Core (stringify) as Json
import Data.Argonaut.Decode.Class (decodeJson)
import Data.Argonaut.Encode.Class (encodeJson)
import Data.Either (Either, either)
import Data.Traversable (traverse_)
import Effect (Effect)
import Effect.Class.Console (log)
import Foreign.Object (singleton) as Obj

appendFoo :: Json -> Either String Json
appendFoo = decodeJson >>> map ((_ <> "foo") >>> encodeJson)

addOne :: Json -> Either String Json
addOne = decodeJson >>> map ((_ + 1) >>> encodeJson)

getFooANdAppendBar :: Json -> Either String Json
getFooANdAppendBar = decodeJson >=> (_ .? "foo") >>> map ((_ <> "bar") >>> encodeJson)

allFunctions :: Array (Json → Either String Json)
allFunctions = [appendFoo, addOne, getFooANdAppendBar]

allArgs :: Array Json
allArgs = [encodeJson 1, encodeJson "foo", encodeJson (Obj.singleton "foo" "bar")]

applyingAllArgsToAllFunctions :: Array (Either String Json)
applyingAllArgsToAllFunctions = allFunctions <*> allArgs

printResults :: Array (Either String Json) → Effect Unit
printResults =  traverse_ log <<< map (either show (caseJson (const "value is Null") show show identity (encodeJson >>> Json.stringify) (encodeJson >>> Json.stringify)))