Foldable

Template trait to define Foldable in terms of foldMap.

Example:

new Foldable[Option] with Foldable.FromFoldMap[Option] {
 def foldMap[A, B](fa: Option[A])(f: A => B)(implicit F: Monoid[B]) = fa match {
   case Some(a) => f(a)
   case None    => F.zero
 }
}

Template trait to define Foldable in terms of foldRight

Example:

new Foldable[Option] with Foldable.FromFoldr[Option] {
 def foldRight[A, B](fa: Option[A], z: B)(f: (A, => B) => B) = fa match {
   case Some(a) => f(a, z)
   case None => z
 }
}