Examples for Java Presentation: "Smarter Types with Records"

A type defines a set of values. Historically we haven't been very good at using encapsulation to ensure that objects stay within that set of values. This article introduces a functional approach to Java type design, using Java's new record keyword to guarantee that each constructed object is a legal value. Your code improves dramatically because now you validate the object in one place, at construction. Because record fields are automatically final, an object cannot be morphed into an illegal value. Such a typed object never needs to be re-checked by any function that receives it as an argument or returns it as a result.