diff --git a/core/src/main/scala/fluence/codec/MonadicalEitherArrow.scala b/core/src/main/scala/fluence/codec/MonadicalEitherArrow.scala index 4ad45c6..240b40f 100644 --- a/core/src/main/scala/fluence/codec/MonadicalEitherArrow.scala +++ b/core/src/main/scala/fluence/codec/MonadicalEitherArrow.scala @@ -49,6 +49,7 @@ abstract class MonadicalEitherArrow[E <: Throwable] { * @tparam B Successful result type */ abstract class Func[A, B] { + f ⇒ /** * Run the func on input, using the given monad. @@ -63,9 +64,9 @@ abstract class MonadicalEitherArrow[E <: Throwable] { * * @param input Input * @param F All internal maps and composes, as well as errors, are to be executed with this MonadError. - * Error type should be a supertype for this arrow's error E. + * Error type should be a supertype for this arrow's error E. */ - def runF[F[_]](input: A)(implicit F: MonadError[F, EE] forSome {type EE >: E}): F[B] = + def runF[F[_]](input: A)(implicit F: MonadError[F, EE] forSome { type EE >: E }): F[B] = runEither(input).flatMap(F.fromEither) /** @@ -76,13 +77,37 @@ abstract class MonadicalEitherArrow[E <: Throwable] { */ def apply[F[_]: Monad](input: A): EitherT[F, E, B] + /** + * Shortcut for function composition + * + * @param other Other function to run after + * @tparam C Resulting input type + * @return Composed function + */ + def on[C](other: Func[C, A]): Func[C, B] = + catsMonadicalEitherArrowChoice.compose(this, other) + + /** + * Convert this Func into another one, lifting the error + * + * @param m Another instance of MonadicalEitherArrow + * @param convertE Convert error + * @tparam EE Error type + * @return Converted function + */ + def to[EE <: Throwable](m: MonadicalEitherArrow[EE])(implicit convertE: E ⇒ EE): m.Func[A, B] = + new m.Func[A, B] { + override def apply[F[_]: Monad](input: A): EitherT[F, EE, B] = + f[F](input).leftMap(convertE) + } + /** * Converts this Func to Kleisli, using MonadError to execute upon and to lift errors into. * * @param F All internal maps and composes, as well as errors, are to be executed with this MonadError. * Error type should be a supertype for this arrow's error E. */ - def toKleisli[F[_]](implicit F: MonadError[F, EE] forSome {type EE >: E}): Kleisli[F, A, B] = + def toKleisli[F[_]](implicit F: MonadError[F, EE] forSome { type EE >: E }): Kleisli[F, A, B] = Kleisli(input ⇒ runF[F](input)) /** @@ -97,11 +122,11 @@ abstract class MonadicalEitherArrow[E <: Throwable] { } /** - * Picks a point from the arrow, using the initial element (Unit) on the left. - * - * @param input Point to pick - * @return Picked point - */ + * Picks a point from the arrow, using the initial element (Unit) on the left. + * + * @param input Point to pick + * @return Picked point + */ def pointAt(input: A): Point[B] = catsMonadicalEitherArrowChoice.lmap(this)(_ ⇒ input) } @@ -187,22 +212,22 @@ abstract class MonadicalEitherArrow[E <: Throwable] { } /** - * Check a condition, lifted with a Func. - * - * @param error Error to produce when condition is not met - * @return Func that takes boolean, checks it, and returns Unit or fails with given error - */ + * Check a condition, lifted with a Func. + * + * @param error Error to produce when condition is not met + * @return Func that takes boolean, checks it, and returns Unit or fails with given error + */ def cond(error: ⇒ E): Func[Boolean, Unit] = liftFuncEither(Either.cond(_, (), error)) /** - * Lift a function which returns a Func arrow with Unit on the left side. - * - * @param f Function to lift - */ - def liftFuncPoint[A, B](f: A ⇒ Point[B]): Func[A,B] = - new Func[A,B]{ - override def apply[F[_] : Monad](input: A): EitherT[F, E, B] = + * Lift a function which returns a Func arrow with Unit on the left side. + * + * @param f Function to lift + */ + def liftFuncPoint[A, B](f: A ⇒ Point[B]): Func[A, B] = + new Func[A, B] { + override def apply[F[_]: Monad](input: A): EitherT[F, E, B] = f(input).apply[F](()) } @@ -240,25 +265,25 @@ abstract class MonadicalEitherArrow[E <: Throwable] { } /** - * Point type maps from Unit to a particular value of A, so it's just a lazy Func. - * - * @tparam A Output value type - */ + * Point type maps from Unit to a particular value of A, so it's just a lazy Func. + * + * @tparam A Output value type + */ type Point[A] = Func[Unit, A] /** - * Point must obey MonadErrorLaws - */ + * Point must obey MonadErrorLaws + */ implicit object catsMonadicalEitherPointMonad extends MonadError[Point, E] { override def flatMap[A, B](fa: Point[A])(f: A ⇒ Point[B]): Point[B] = - new Func[Unit, B]{ - override def apply[F[_] : Monad](input: Unit): EitherT[F, E, B] = + new Func[Unit, B] { + override def apply[F[_]: Monad](input: Unit): EitherT[F, E, B] = fa[F](()).flatMap(f(_).apply[F](())) } override def tailRecM[A, B](a: A)(f: A ⇒ Point[Either[A, B]]): Point[B] = - new Func[Unit, B]{ - override def apply[F[_] : Monad](input: Unit): EitherT[F, E, B] = + new Func[Unit, B] { + override def apply[F[_]: Monad](input: Unit): EitherT[F, E, B] = Monad[EitherT[F, E, ?]].tailRecM(a)(f(_).apply[F](())) } @@ -266,8 +291,8 @@ abstract class MonadicalEitherArrow[E <: Throwable] { liftFuncEither(_ ⇒ Left(e)) override def handleErrorWith[A](fa: Point[A])(f: E ⇒ Point[A]): Point[A] = - new Func[Unit, A]{ - override def apply[F[_] : Monad](input: Unit): EitherT[F, E, A] = + new Func[Unit, A] { + override def apply[F[_]: Monad](input: Unit): EitherT[F, E, A] = fa[F](()).leftFlatMap(e ⇒ f(e).apply[F](())) } @@ -298,9 +323,9 @@ abstract class MonadicalEitherArrow[E <: Throwable] { Bijection(liftFuncEither(direct), liftFuncEither(inverse)) /** - * Lifts point functions into Bijection. - */ - def liftPointB[A,B](direct: A ⇒ Point[B], inverse: B ⇒ Point[A]): Bijection[A,B] = + * Lifts point functions into Bijection. + */ + def liftPointB[A, B](direct: A ⇒ Point[B], inverse: B ⇒ Point[A]): Bijection[A, B] = Bijection(liftFuncPoint(direct), liftFuncPoint(inverse)) /**