Zero cost json serialization and zero copy deserialization for a subset of PureScript types.
This library exploits internal JavaScript representations of some PureScript types to allow simple serialization and deserialization of their values.
It provides simple class SonJ a which proofs serializiblity of a given type.
Currently supported types are: Number, String, Int, Boolean, Record, Variant, Array, Null (defined internally) and newtype (with Newtype instance) around any serializable type.
-- | Nearly zero cost
dump ∷ ∀ a. SonJ a ⇒ a → Json
unsafeLoad ∷ ∀ a. SonJ a ⇒ Json → a
-- | Zero copy but with validation (json traversing) cost
load ∷ ∀ a. SonJ a ⇒ Json → Maybe aThis is excerpt of test/Main.purs:
unsafeRoundTrip ∷ ∀ a. SonJ a ⇒ a → Maybe a
unsafeRoundTrip = SonJ.dump >>> stringify >>> jsonParser >>> hush >>> map SonJ.unsafeLoad
roundTrip ∷ ∀ a. SonJ a ⇒ a → Maybe a
roundTrip = SonJ.dump >>> stringify >>> jsonParser >>> hush >=> SonJ.load
type MaybeV a = Variant (just ∷ a, nothing ∷ Null)
just ∷ ∀ a. a → MaybeV a
just = inj (SProxy ∷ SProxy "just")
nothing ∷ ∀ a. MaybeV a
nothing = inj (SProxy ∷ SProxy "nothing") null
newtype X a b = X { a ∷ a, b ∷ b }
derive instance eqX ∷ (Eq a, Eq b) ⇒ Eq (X a b)
derive instance newtypeX ∷ Newtype (X a b) _
main ∷ Effect Unit
main = do
logShow (unsafeRoundTrip (just 8) == Just (just 8))
logShow (unsafeRoundTrip (just 9) /= Just (just 8))
logShow (unsafeRoundTrip (X {a: 8, b: just "test"}) == Just (X {a: 8, b: just "test"}))
logShow (unsafeRoundTrip (X {a: 8, b: just "test"}) /= Just (X {a: 8, b: nothing }))
logShow (unsafeRoundTrip (X {a: 8, b: nothing ∷ MaybeV Int}) == Just (X {a: 8, b: nothing }))
logShow (roundTrip (just 8) == Just (just 8))
logShow (roundTrip (just 9) /= Just (just 8))
logShow (roundTrip (X {a: 8, b: just "test"}) == Just (X {a: 8, b: just "test"}))
logShow (roundTrip (X {a: 8, b: just "test"}) /= Just (X {a: 8, b: nothing }))
logShow (roundTrip (X {a: 8, b: nothing ∷ MaybeV Int}) == Just (X {a: 8, b: nothing }))