A sighting of sequence function in Practical FP in Scala

Transcript

1. sequence
   a sighting of
   in
   @philip_schwarz
   slides by http://fpilluminated.com/
   by
   

   View Slide

2. View Slide

3. ^⇧P Type Info
   ^⇧P Type Info
   

   View Slide

4. @typeclass trait Traverse[F[_]] extends Functor[F] with Foldable[F] with …
   …
   Thread all the G effects through the F structure to invert the structure from F[G[A]] to G[F[A]].
   def sequence[G[_]: Applicative, A](fga: F[G[A]]): G[F[A]] =
   traverse(fga)(ga => ga)
   List[F[Unit]] => F[List[Unit]]
   case class CartRoutes[F[_]: JsonDecoder: Monad]
   Applicative
   Monad
   Functor
   Traverse
   Foldable
   

   View Slide