Lenses Composition

lensesComposition.swift

precedencegroup ComposePrecedence {

    associativity: left
}

infix operator >>> : ComposePrecedence

func >>> <Container, View, Subview>(lhs: Lens<Container, View>, rhs: Lens<View, Subview>) -> Lens<Container, Subview> {

    return Lens(
        get: { container in
            let view = lhs.get(container)
            let subview = rhs.get(view)
            return subview
        },
        set: { (container, subview) in
            let initialView = lhs.get(container)
            let updatedView = rhs.set(initialView, subview)
            return lhs.set(container, updatedView)
        }
    )
}