OOP as if you meant it

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OOP as if you meant it

Today´s mainstream object orientation is not what Alan Kay, the inventor of the term, intended:

I invented the term object-oriented, and I can tell you that C++ wasn't what I had in mind.

To him, a core feature of object orientation was messaging, i.e. some form of “natural” communication:

I thought of objects being like biological cells and/or individual computers on a network, only able to communicate with messages.

Messaging was so important to him that he listed it as second in his definition of object orientation:

1. Everything is an object, 2. Objects communicate by sending and receiving messages [...]

And when asked, what´s lacking in today´s object orientation he explicitly said:

The big idea is “messaging”.

But what is messaging? How can we do it with todays mainstream OO languages?

That´s what I´ve thought about and wrote a couple of articles about in this blog. Here´s a chronological list of them for easy reference:

Messaging as a Programming Model – Let´s get real – With my stab at a definition of what “messaging” means.
Flows – Visualizing the Messaging Programming Model – How to work with messaging apart from code
Messaging for More Decoupling – Explaining my first principle of messaging, the Principle of Mutual Oblivion (PoMO)
Nested Messaging – Flows on Different Levels of Abstraction – Explaining my second principle of messaging, the Integration Operation Segregation Principle (IOSP)
Bus or Flow? – Messing Done One Way or the Other – Comparing different ways of doing messaging
Focus on the Flow with Messaging – An example of applying messaging to a scenario found on the internet

I think, if we really mean to do object oriented programming, we need to adopt messaging as a core feature of our code. I´d be glad if these articles help you to make the switch.