async.m

#import <stdio.h>
#import "AsyncRuntime.h"

#pragma clang assume_nonnull begin

@namespace(Utilities)

+ (Promise *)delayForSeconds: (OFTimeInterval)seconds onScheduler: (AsyncScheduler *)scheduler;

@end

@implementation Utilities

+ (Promise *)delayForSeconds: (OFTimeInterval)seconds onScheduler: (AsyncScheduler *)scheduler
{
    PromiseResolver *resolver = [[PromiseResolver alloc] init];
    OFDate *fireDate = [[OFDate alloc] initWithTimeIntervalSinceNow: seconds];
    OFTimer *timer = [[OFTimer alloc] initWithFireDate: fireDate interval: 0 repeats: false block: ^(OFTimer *unusedTimer) {
        (void)unusedTimer;
        [resolver resolve: AsyncUnit.unit];
    }];

    [scheduler.runLoop addTimer: timer forMode: scheduler.mode];
    return resolver.promise;
}

@end

@interface App : OFObject<OFApplicationDelegate> @end

@implementation App

- (void)applicationDidFinishLaunching: (OFNotification *)notification
{
    (void)notification;

    AsyncScheduler *scheduler = [[AsyncScheduler alloc] initWithRunLoop: $assert_nonnil(OFRunLoop.currentRunLoop)];

    Task<OFString *> *greetingTask = [[Task alloc] initWithScheduler: scheduler schedulingBlock: ^OFString *(Task<OFString *> *) {
        puts("Greeting task: waiting for timer");
        [[Utilities delayForSeconds: 0.10 onScheduler: scheduler] await];
        puts("Greeting task: resolved");
        return @"hello from the ObjFW run loop";
    }];

    Task *counterTask = [[Task alloc] initWithScheduler: scheduler schedulingBlock: ^AsyncUnit *(Task *) {
        for (int i = 0; i < 3; i++) {
            printf("Counter task: step %d\n", i);
            [[Utilities delayForSeconds: 0.15 onScheduler: scheduler] await];
        }

        return AsyncUnit.unit;
    }];

    (void)[[Task alloc] initWithScheduler: scheduler schedulingBlock: ^AsyncUnit *(Task *) {
        @try {
            OFString *greeting = greetingTask.await;
            [counterTask await];
            printf("Watcher task: %s\n", greeting.UTF8String);
            [OFApplication terminate];
        } @catch (OFException *exception) {
            fprintf(stderr, "Demo failed: %s\n", exception.description.UTF8String);
            [OFApplication terminateWithStatus: 1];
        }

        return AsyncUnit.unit;
    }];
}

@end


#pragma clang assume_nonnull end

OF_APPLICATION_DELEGATE(App);