README

This package is a PHP port of the java.util.Optional class in the OpenJDK libraries.

Currently maintained by Niklas Schöllhorn, taken over 3rd March, 2019

You can find the API of java.lang.Optional in the Java 8 API docs.

Installation

composer require ocramius/optional

Differences with the Java implementation

Because of PHP's current limitations, I had to rewrite some bits of the Java implementation as follows:

• Optional#empty() is named Optional#newEmpty(), because empty is a reserved PHP keyword
• type-safety is not ensured at any time: generics have simply been stripped from the Optional implementation. This may change in future, but I don't plan to do it right now.
• Optional#toString() is named Optional#__toString() in accordance to PHP magic methods naming
• Consumer, Predicate, Function and Supplier arguments are simply callable, for simplicity and flexibility.

License

Since this library is a direct port of the OpenJDK sources, I have to keep the original license in place, which is GPLv2 + ClassPath exceptions.