The Perfect Analogy for _Flows_?

[GrokkingGrok]

The Perfect Flow Analogy?

Imagine you have a blow gun that shoots one dart at a time. In this example, each dart would be a flow moving from one actor, you, the source, to another actor, the target.

You have three kinds of darts.

• One is a normal dart. You shoot it, it either hits its target or misses.
• Another has a string attached to it.
  • If you hit your target, you can pull the string tight and transfer messages along it like with two cups and a string as long as its stuck in the target.
  • This is a persistent flow.
• The final kind of dart is very special.
  • If this dart hits its target, it can shoot more darts and hit other targets automatically.
  • And some of those are special darts as well, they shoot their own darts if they hit their targets.
  • But you, the actor who shot it, are responsible for making sure you hit the initial target.
  • And if you're expecting something in return, and don't get it, you're also responsible for shooting another dart.
• We, the programmers, are responsible for making sure misses don't happen, and that if they do, the program doesn't crash.

I just added this to the contributing doc. It's getting to be a good design document.