What are use cases for coroutines?
The concept of a coroutine sounds very interesting, but I don't know, if it makes sense in a real productive environment? What are use cases for coroutines, where the coroutine implementation is more elegant, simpler or more efficient than other methods?
Answer
One use case is a web server that has multiple simultaneous connections, with a requirement to schedule reading and writing in parallel with all of them.
This can be implemented using coroutines. Each connection is a coroutine that reads/writes some amount of data, then yields control to the scheduler. The scheduler passes to the next coroutine (which does the same thing), cycling through all the connections.