2 ms·
No higher-rank types in Scala, I'm afraid. As for the monoid instance: def pairMonoid[A,B](a:Monoid[A],b:Monoid[B]) = new Monoid[(A, B)] { def empty = (a.em
by runaro 17y ago
No higher-rank types in Scala, I'm afraid.
As for the monoid instance:
def pairMonoid[A,B](a:Monoid[A],b:Monoid[B]) = new Monoid[(A, B)] {
def empty = (a.empty, b.empty)
...
}