Comonad

Comonad.scala

// Comonad is the dual of Monad
// example for non empty list, extract is the head of the list
// coflatMap gives you successive lists from the whole list, the tail, the tail of that 
// and you must return a single value for each list...

@ Comonad[NonEmptyList].extract(NonEmptyList.of(1,2,3)) 
res26: Int = 1

@ Comonad[NonEmptyList].extract(NonEmptyList.of(1)) 
res27: Int = 1

@ Comonad[NonEmptyList].coflatMap(NonEmptyList.of(1,2,3,4,5,6,7,8,9,10)){_.head} 
res28: NonEmptyList[Int] = NonEmptyList(1, List(2, 3, 4, 5, 6, 7, 8, 9, 10))

@ Comonad[NonEmptyList].coflatMap(NonEmptyList.of(1,2,3,4,5,6,7,8,9,10)){_.size} 
res29: NonEmptyList[Int] = NonEmptyList(10, List(9, 8, 7, 6, 5, 4, 3, 2, 1))