Foo.purs

module Types.Foo where

import Prelude
import Data.Argonaut ((~>), (:=), (.?), jsonEmptyObject)
import Data.Argonaut.Encode (EncodeJson, encodeJson)
import Data.Argonaut.Decode (DecodeJson, decodeJson)
import Data.Maybe (Maybe(..))

type Foo =
  { foo :: Maybe Number
  , bar :: Maybe String
  }

newtype FooNT = FooNT
  { foo :: Maybe Number
  , bar :: Maybe String
  }

instance decodeJsonFooNT :: DecodeJson FooNT where
  decodeJson json = do
    obj <- decodeJson json
    foo <- obj .? "foo"
    bar <- obj .? "bar"
    pure $ FooNT {foo: foo, bar: bar}

instance encodeJsonFooNT :: EncodeJson FooNT where
  encodeJson (FooNT f)
    =  "bar" := f.bar
    ~> "foo" := f.foo
    ~> jsonEmptyObject

instance showFooNT :: Show FooNT where
  show (FooNT f) = "Foo {foo: " ++ show f.foo ++ ", bar:" ++ show f.bar ++ "}"

runFoo :: FooNT -> Foo
runFoo (FooNT f) = f

initialFoo :: Foo
initialFoo =
  { foo: Just 42.0
  , bar: Nothing
  }

foo :: FooNT
foo = FooNT initialFoo

encodedFoo = encodeJson foo