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Functional programming in Kotlin with Arrow

Functor Typeclass

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The functor is one of the most well-known typeclasses. It's on top of the hierarchy for the applicative and the monad, since both extend from it. Learn:

  • Inheritance relation between Functor, Applicative and Monad.
  • How the Functor provides mapping behavior and how's that probably needed on any app.
  • Examples of mapping with functor instances of some known data types like Option<A> or Either<L, R>.
  • Why we say some data types are biased and how that affects to combinators like map.
  • How to provide or write your own Functor instances.
  • How to use map to stack computations over data.


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Lessons in Functional programming in Kotlin with Arrow