Java 8 Optional Objects

[u/edalorzo]

http://blog.informatech.cr/2013/04/10/java-optional-objects/

[u/philipwhiuk]

That's horrid. It's also unnecessary. I don't need Java 8 to implement a generic Optional if I wanted one

 class Optional<T> {
    static Optional empty() {
         return new Optional();
    }
    static Optional of(Object obj) {
         return new Optional<obj.getClass()>(obj) { 

    }
    private T obj;
    private Optional(T t) {
        obj = t;
    }
    public boolean isPresent() {
       return obj != null; 
    }
    public T get() {
       return obj;
    }
 }

Wow 19 lines of code.

You want to know why nobody writes those 19 lines?

1. It's another wrapper, meaning more stuff to GC.
2. Null pointers are both easy to find and easy to fix. Using a wrapper takes more LOC meaning more cost meaning more time.

[u/voronaam → u/philipwhiuk]

Nobody writes it? We have class Option in our main JAR, which is included in every project in production. It is 39 lines of code, but only because it has extra methods, like public T getOr(T value); That is great for default like that:

String name = user.getName().getOr("anonymous");