What good are right-associative methods in Scala?

Question

I\'ve just started playing around with Scala, and I just learned about how methods can be made right-associative (as opposed to the more traditional left-associ

Answer 1

Right-associativity and Left-associativity plays an important role when you are performing List fold operations. For eg:

def concat[T](xs: List[T], ys: List[T]): List[T] = (xs foldRight ys)(_::_)

This works perfectly fine. But you cannot perform the same using foldLeft operation

def concat[T](xs: List[T], ys: List[T]): List[T] = (xs foldLeft ys)(_::_)

,because :: is right-associative.