[rafram]

I just completely disagree. Async is syntactic sugar that can be reduced to sync code with callbacks. It doesn’t exist on equal footing. If you want to call sync code from async code, you just… call it. If it performs blocking IO, it’ll block, but that’s exactly what it would do if called from other sync code, too.

By contrast, calling async code from sync code requires a special blocking wrapper (Python) or unavoidably breaks control flow (JavaScript).

[scotty79]

> By contrast, calling async code from sync code requires a special blocking wrapper (Python) ...

That's exaclty my point. If you don't have async by default in your platform you need to do stupid things to fake it. If function calls and main in Python were innately async you could be calling async code just as easily as sync code.

> [...] or unavoidably breaks control flow (JavaScript).

async/await syntax avoids it completely.

Tbh await should be default function call semantics and there should be special keyword for calling without awaiting. But since we come from sync primitives that would require small revolution that might happen at some point.

> Async is syntactic sugar

You could make sync code be syntactic sugar for await.

[gpderetta]

> would require small revolution that might happen at some point.

or python could have blessed gevent and done away with all the nonsense.

[btown]

I hope that someone does an oral history of why gevent wasn't seen as the solution here. The existence of models like Twisted, and a general idea that yields to an event thread should be explicit in some way, I think caused the exact kind of fracturing of the ecosystem that everyone was trying to avoid. "Everyone will write async code" simply didn't happen in practice.

[v3ss0n]

So many production problems that we never seen in development comes in and no way to debug

[v3ss0n]

You had never tried gevent in production then. As soon as workload and concurrency increases python programs with gevent or gevent based drivers, especially monkey patches causes unexpected crashes out of the blue, no way to debug, no error message,Memory leaks and whole slew of nightmares

[crubier]

> Tbh await should be default function call semantics and there should be special keyword for calling without awaiting.

Your comment made me realize this is exactly what golang "go" keyword does. This is actually great.

[gpderetta]

also Cilk spawn.

[BerislavLopac]

> Async is syntactic sugar that can be reduced to sync code with callbacks

The whole point of introducing async was to get away from callback hell.

[rafram]

Yeah, I’m not saying that callbacks are good, I’m saying that async is a veneer over callbacks.