http://reactivex.io
The real power comes with the “reactive extensions” (hence “ReactiveX”) — operators that allow you to transform, combine, manipulate, and work with the sequences of items emitted by Observables.
These Rx operators allow you to compose asynchronous sequences together in a declarative manner with all the efficiency benefits of callbacks but without the drawbacks of nesting callback handlers that are typically associated with asynchronous systems.
原文：https://www.cnblogs.com/feng9exe/p/9004650.html