Asynchronous Programming

Completion of other work while waiting for a complex operation to finish. The complex operation is usually set to be the asynchronous function.

Terminology

• Synchronous operation: Blocks other operations from executing till it completes
• Synchronous function: Only syncOp
• Asynchronous operation: Allows other operations to execute before it completes
• Asynchronous function: >=1 asyncOp

futures

• future: instance of Future class
  • Represents result of asyncOp:
    • Uncompleted, waiting for asyncOp to finish or throw an error
    • Completed, returns value for successful asyncOp, or throw error

• Future<ReturnValueType>: class returning future value of ReturnValueType

async

await

Generators (*)

• Function which returns multiple values
• e.g., sync function returns int, async function returns Future<int>, sync generator returns Iterable<int>, async generator returns Stream<int>
• Uses yield instead of return