Modular•14mo ago

how to use async in mojo?

async fn add_three(a: Int, b: Int, c: Int) -> Int:
    let sum:Int = a + b + c;
    return sum

async fn main():
    let task: Coroutine[Int] = add_three(1, 2, 3)
    let result:Int = await task
    print(result)

async fn add_three(a: Int, b: Int, c: Int) -> Int:
    let sum:Int = a + b + c;
    return sum

async fn main():
    let task: Coroutine[Int] = add_three(1, 2, 3)
    let result:Int = await task
    print(result)

I did what mojo bot told me to do, but I got the error below.

/__w/modular/modular/Kernels/mojo/builtin/_startup.mojo:70:1: error: caller input parameter #0 has type '!kgen.signature<() async -> !lit.none>' but callee expected type '!kgen.signature<() -> !lit.none>'
mojo: error: failed to run the pass manager

/__w/modular/modular/Kernels/mojo/builtin/_startup.mojo:70:1: error: caller input parameter #0 has type '!kgen.signature<() async -> !lit.none>' but callee expected type '!kgen.signature<() -> !lit.none>'
mojo: error: failed to run the pass manager

4 Replies

jmky•14mo ago

i think you need to do await task()

Alex Kirchhoff•14mo ago

The current version of Mojo does not support main being marked as async. You can cause coroutines to be executed on the calling thread by calling them (e.g. let result: Int = task()), but this kind of defeats the whole point of async. There is not really much you can do with async in Mojo right now until we build out more of the infrastructure around it.

silverviolin.•9mo ago

@Alex Kirchhoff May I ask about our usage plan for async based on coroutines, which version of mojo is expected to achieve the effect of immediate execution?

miilirgur•9mo ago

python

Gaming

Programming

how to use async in mojo?