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FrontEndMasters Async Javascript
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Fundamentals JavaScript
Look back what we've gone throughQuiz

Callback Hell?   
Inversion of control: don't have control over how many times your callback will be called and how (error first, etc.)
unreasonability: async code with callbacks doesn't flow the same way our brains work

We need higher-order patterns to address these issues. It's not about indentation and too many crying moustaches

What is a Promise
- future value. A completion event. (​.then​). It's a callback manager. They're designed with the trust in mind. 

How do you pause a generator? ​yield​ resume it: ​next

How do you combine generators and promises for flow control? Yielding a promises. And promise resumes the generator.