duemunk/Async

Async.userInitiated {
	10
}.background {
	"Score: \($0)"
}.main {
	label.text = $0
}

DispatchQueue.global(qos: .userInitiated).async {
	let value = 10
	DispatchQueue.global(qos: .background).async {
		let text = "Score: \(value)"
		DispatchQueue.main.async {
			label.text = text
		}
	}
}

let group = AsyncGroup()
group.background {
    print("This is run on the background queue")
}
group.background {
    print("This is also run on the background queue in parallel")
}
group.wait()
print("Both asynchronous blocks are complete")

dependencies: [
    .package(url: "https://github.com/duemunk/Async", from: "2.1.0"),
],

use_frameworks!
pod "AsyncSwift"

github "duemunk/Async"

Async.main {}
Async.userInteractive {}
Async.userInitiated {}
Async.utility {}
Async.background {}

Async.userInitiated {
	// 1
}.main {
	// 2
}.background {
	// 3
}.main {
	// 4
}

let backgroundBlock = Async.background {
	print("This is run on the background queue")
}

// Run other code here...

// Chain to reference
backgroundBlock.main {
	print("This is run on the \(qos_class_self().description) (expected \(qos_class_main().description)), after the previous block")
}

let customQueue = DispatchQueue(label: "CustomQueueLabel", attributes: [.concurrent])
let otherCustomQueue = DispatchQueue(label: "OtherCustomQueueLabel")
Async.custom(queue: customQueue) {
	print("Custom queue")
}.custom(queue: otherCustomQueue) {
	print("Other custom queue")
}

let seconds = 0.5
Async.main(after: seconds) {
	print("Is called after 0.5 seconds")
}.background(after: 0.4) {
	print("At least 0.4 seconds after previous block, and 0.9 after Async code is called")
}

// Cancel blocks not yet dispatched
let block1 = Async.background {
	// Heavy work
	for i in 0...1000 {
		print("A \(i)")
	}
}
let block2 = block1.background {
	print("B – shouldn't be reached, since cancelled")
}
Async.main {
	// Cancel async to allow block1 to begin
	block1.cancel() // First block is _not_ cancelled
	block2.cancel() // Second block _is_ cancelled
}

let block = Async.background {
	// Do stuff
}

// Do other stuff

block.wait()

let previousBlock = {}
let chainingBlock = {}
let dispatchQueueForChainingBlock = ...

// Use the GCD API to extend the blocks
let _previousBlock = dispatch_block_create(DISPATCH_BLOCK_INHERIT_QOS_CLASS, previousBlock)
let _chainingBlock = dispatch_block_create(DISPATCH_BLOCK_INHERIT_QOS_CLASS, chainingBlock)

// Use the GCD API to call back when finishing the "previous" block
dispatch_block_notify(_previousBlock, dispatchQueueForChainingBlock, _chainingBlock)

Apply.background(100) { i in
	// Do stuff e.g. print(i)
}

let group = AsyncGroup()
group.background {
    // Run on background queue
}
group.utility {
    // Run on utility queue, in parallel to the previous block
}
group.wait()

group.main {}
group.userInteractive {}
group.userInitiated {}
group.utility {}
group.background {}

let customQueue = dispatch_queue_create("Label", DISPATCH_QUEUE_CONCURRENT)
group.custom(queue: customQueue) {}

let group = AsyncGroup()
group.background {
    // Do stuff
}
group.background {
    // Do other stuff in parallel
}
// Wait for both to finish
group.wait()
// Do rest of stuff

let group = AsyncGroup()
group.enter()
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)) {
    // Do stuff
    group.leave()
}
group.enter()
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)) {
    // Do other stuff in parallel
    group.leave()
}
// Wait for both to finish
group.wait()
// Do rest of stuff