Functional Ruby

Another repo for showing some functional properties for the Ruby language

Features

Taken from Functors, Applicatives, And Monads In Pictures from Haskell

Maybe

Understands functor map function

just = Maybe 2

Just(42).map { |x| x * x } 
Just(1764)

Nothing.map {|x| x * x}
Nothing

Also bind

maybe_m >>= proc {|i| i + 4}
5

And applicatives

Just do |x, y|
      x ** y
    end.apply(pure(421)).apply(pure(2))
Just(177241)

proc {|x,y| x*y} % Just(5) & Just(3) 
Just(15)

Even lifting

pure(5).lift_a2 proc {|x,y| x*y}, pure(3)
Just(15)