Immutability is an important principle of functional programming. Mutable objects hide changes. And hidden changes can lead to unpredictability and chaos.
FunctionalJ provides ways to create and manipulate immutable data. In this article, I discuss @Struct, which generates custom immutable classes. On the surface, it is very similar in concept with Lombok's @Value. However, FunctionalJ's @Struct comes with its own unique features, such as: