Learn Functional Programming course/tutorial on Scala

Solutions by @spavikevik.

Type classes

• Observe general type class pattern in learnfp/typeclass/TypeClass.scala.
• Implement learnfp/typeclass/TotalOrder.scala
• Implement learnfp/typeclass/Show.scala
• Implement learnfp/typeclass/Eq.scala
• Extra material:
  • https://blog.scalac.io/2017/04/19/typeclasses-in-scala.html

Monoids

• Observe general monoid pattern in learnfp/monoid/Monoid.scala
• Implement learn-fp/src/main/scala/learnfp/monoid/ListMonoid.scala
• Implement learn-fp/src/main/scala/learnfp/monoid/SimpleMonoid.scala
• Implement learnfp/monoid/PairAdditiveMonoid.scala
• Extra material:
  • Bartosz Milewski: Category Theory 3.1: Examples of categories, orders, monoids

Functors

• Observe general functor pattern in learnfp/functor/Functor.scala
• Implement learnfp/functor/Id.scala
• Implement learnfp/functor/Maybe.scala
• Implement learnfp/functor/List.scala
• Implement learnfp/functor/Disjunction.scala
• Implement learnfp/functor/Writer.scala
• Implement learnfp/functor/State.scala
• Extra material:
  • http://learnyouahaskell.com/functors-applicative-functors-and-monoids
  • https://thedet.wordpress.com/2012/04/28/functors-monads-applicatives-can-be-so-simple/
  • Bartosz Milewski: Category Theory 6.1: Functors

Monads

• Observe general monad pattern in learnfp/monad/Monad.scala
• Implement learnfp/monad/Id.scala
• Implement learnfp/monad/Maybe.scala
• Implement learnfp/monad/List.scala
• Implement learnfp/monad/Disjunction.scala
• Implement learnfp/monad/Writer.scala
• Implement learnfp/monad/State.scala
• Extra material
  • Brian Beckman: Don't fear the Monad
  • http://eed3si9n.com/learning-scalaz/Monad+transformers.html

Foldable

• Implement foldable in learnfp/foldable/Foldable.scala

Applicatives

• Observe general applicative pattern in learnfp/applicative/Applicative.scala
• Implement learnfp/applicative/Id.scala
• Implement learnfp/applicative/Maybe.scala
• Implement learnfp/applicative/List.scala
• Implement learnfp/applicative/Disjunction.scala
• Implement learnfp/applicative/Writer.scala
• Implement learnfp/applicative/State.scala
• Extra material
  • https://en.wikibooks.org/wiki/Haskell/Applicative_functors
  • http://eed3si9n.com/learning-scalaz/Applicative.html

Traversable

• Implement learnfp/traversable/Traversable.scala

Nested

• Implement learnfp/nested/Nested.scala

IO

• Implement learnfp/nested/IO.scala

Monad Transformers

• Observe general monad transformer typeclass in learnfp/transformer/MonadTransformer.scala
• Implement learnfp/transformer/IdT.scala
• Implement learnfp/transformer/MaybeT.scala
• Implement learnfp/transformer/WriterT.scala
• Implement learnfp/transformer/StateT.scala
• Extra material:
  • http://eed3si9n.com/learning-scalaz/Monad+transformers.html

Free monad

• Implement learnfp/free/Free.scala and pass all unit tests in learn-fp/src/test/scala/learnfp/free/FreeTest.scala
• Extra material:
  • http://blog.krobinson.me/posts/monads-part-2-the-free-monad/
  • https://underscore.io/blog/posts/2015/04/14/free-monads-are-simple.html

Contravariant functor

• Observe general contravariant functor pattern in learnfp/contravariant/ContravariantFunctor.scala
• Implement learnfp/contravariant/Show.scala
• Implement learnfp/contravariant/Predicate.scala

CoMonads

• Observe general comonad pattern in learnfp/comonad/CoMonad.scala
• Implement learnfp/comonad/Id.scala
• Implement learnfp/comonad/Env.scala

Bonus

• Implement Reader functor, monad, applicative and write unit tests for that
• Implement ReaderT and write unit tests for that
• Implement applicative for monad transformers
• Implement applicative for Free

Credits

• Yuriy Netesov (@dehun)