shoheiyokoyama

let queue = DispatchQueue(label: "queue", attributes: .concurrent)
let workItem = DispatchWorkItem {
    sleep(2)
    print("done")
}
    
queue.async(execute: workItem)
    
workItem.notify(queue: .main) {
    print("notify!")

shoheiyokoyama

let queue = DispatchQueue(label: "queue", attributes: .concurrent)
let workItem = DispatchWorkItem {
    sleep(3)
    print("done")
}
    
queue.async(execute: workItem)
print("before waiting")
workItem.wait()
print("after waiting")

shoheiyokoyama

let queue = DispatchQueue(label: "queue", attributes: .concurrent)
let workItem = DispatchWorkItem {
    print("done")
}
    
DispatchQueue.main.asyncAfter(deadline: .now() + .seconds(1)) {
    queue.async(execute: workItem) // not work
}
workItem.cancel()

shoheiyokoyama

let workItem = DispatchWorkItem {
    sleep(1)
    print("done")
}
    
workItem.perform() // Execute synchronously
print("after perfrom") 

//done
//after perfrom

shoheiyokoyama

applyTwice :: (a -> a) -> a -> a
applyTwice f x = f (f x)

shoheiyokoyama

Prelude> max 4 5
5
Prelude> (max 4) 5
5

shoheiyokoyama

extension String {
    func isNumber() -> Bool {
        let pattern = "^[\\d]+$"
        guard let regex = try? NSRegularExpression(pattern: pattern) else { return false }
        let matches = regex.matches(in: self, range: NSRange(location: 0, length: length))
        return matches.count > 0
    }
}

shoheiyokoyama

@available(iOS 10.0, *)
public enum NCWidgetDisplayMode : Int {


    case compact // Fixed height

    case expanded // Variable height
}

shoheiyokoyama

        let group  = DispatchGroup()
        let queue1 = DispatchQueue(label: "com.GCD.groupQueue1")
        let queue2 = DispatchQueue(label: "com.GCD.groupQueue2")
        let queue3 = DispatchQueue(label: "com.GCD.groupQueue3")

        queue1.async(group: group) {
            sleep(4)
            print("excute queue1")
        }

shoheiyokoyama

public class DegitObserver implements Observer {
    public void update(NumberGenerator generator) {
        System.out.println("DegitObserver:" + generator.getNumber());
        try {
            Thread.sleep(100);
        } catch (InterruptedException e) {

        }
    }
}