FunctionalComposition.swift

infix operator <<< { associativity right }
func <<< <A, B, C>(f: B -> C, g: A -> B) -> A -> C {
	return composeBackward(f, g: g)
}

infix operator >>> { associativity left }
func >>> <A, B, C>(g: A -> B, f: B -> C) -> A -> C {
	return composeForward(g, f: f)
}

func composeBackward <A, B, C>(f: B -> C, g: A -> B) -> A -> C {
	return { x in f(g(x)) }
}

func composeForward <A, B, C>(g: A -> B, f: B -> C) -> A -> C {
	return { x in f(g(x)) }
}