import context
import time
import x.async as xasync

fn main() {
    mut group := xasync.new_group(context.background())

    group.go(fn (mut ctx context.Context) ! {
        _ = ctx
        time.sleep(20 * time.millisecond)
        return error('stop group')
    })!

    group.go(fn (mut ctx context.Context) ! {
        done := ctx.done()
        select {
            _ := <-done {
                return ctx.err()
            }
            1 * time.second {
                return error('worker did not observe cancellation')
            }
        }
    })!

    group.wait() or {
        println('group failed: ${err.msg()}')
        return
    }
}