Immutable Types with Changing State in Swift

This article discusses the concept of immutability in Swift from a functional programming perspective. It addresses the common struggle of reconciling immutability with the need for changing state, explaining that instead of mutating objects, functional programming creates new instances with the desired changes. The article provides a practical Swift example using a Scorekeeper class, comparing a mutating approach (using var and in-place updates) with an immutable approach (using let and returning new instances). It is a technical tutorial aimed at Swift developers looking to adopt functional programming practices.