Type Problems — Development skill for Claude Code

Type problems

A set of problems to improve your skills with `TyDD, Type Driven Development` with Java and some additional Functional libraries.

Motivation

Using Java, the developers implements the solutions, transforming data with different nature. We will consider that data as `Values`. That values will be encapsulated into Objects. For the design of your values, you will use [Java primitives](https://docs.oracle.com/javase/tutorial/java/nutsandbolts/datatypes.html) or [Java wrapper classes](https://en.wikipedia.org/wiki/Primitive_wrapper_class):


From Java 8, you can use `Monads`, a parameterized Types to wrap values into a context and apply functions on it. What Monads are available in Java 8+?

• Stream< T >
• Optional< T >
• CompletableFuture< T >

Using third party libraries like VAVR, you could add new `Monads` like:

• Try< T >
• Either< L ,R >

Or you could use new ones from Reactor to model your Reactive problems:

• Mono< T >
• Flux< T >

The following problems was designed to improve your skills modeling solutions.

Null safety

Java accept `null` values when you assign to a Type although it is harmful. Using `JSR-305` meta-annotations like `@NonNull` or using `JSR 303` & `JSR 380` Bean validations, you could indicate that your programs only accept Non null values. Another alternative to mitigate the usage of `null` values in your programs is with the usage of the M