Lightning talk about monad transformers.

1. 8 MINUTES OF
MONAD
TRANSFORMERS
THINGS THAT YOU ARE AFRAID TO
ASK HASKELL DEVELOPERS

2. ...you don't need to know what is it in case of this topic.
MONADS
8MINUTESOF MONADTRANSFORMERS
Future("1")
.map(_ + "0")
.map(_.toInt)
// result: 10
List("1", "2", "3", "4")
.map(_.toInt)
.map(_ * 2)
// result: [2, 4, 6, 8]

3. ...you don't need to know what is it in case of this topic.
MONADS
8MINUTESOF MONADTRANSFORMERS
Future("1")
.map(_ + "0")
.map(_.toInt)
// result: 10
List("1", "2", "3", "4")
.map(_.toInt)
.map(_ * 2)
// result: 2, 4, 6, 8

4. ...you don't need to know what is it in case of this
topic.
MONAD
8MINUTESOF MONADTRANSFORMERS
Future(List("1", "2", "3"))
.map(???)

5. ...way to use nested monads.
MONAD T
8MINUTESOF MONADTRANSFORMERS
Future(List("1", "2", "3"))
.map(_.map(doSmth))

6. ...way to use nested monads.
MONAD T
8MINUTESOF MONADTRANSFORMERS
implicit class FutureListMonadT[A](a: Future[List[A]]) {
def mapT[B](f: A => B): Future[List[B]] =
a.map(_.map(f))
}
Future(List("1", "2", "3"))
.mapT(doSmth)

7. THANKS!
TIME TO ARGUE