@FunctionalInterface
interface Funktion {
    int fkt(int a, int b);
}

@FunctionalInterface
interface Doit {
    void doit();
}


public class LambdaAusdruecke {
    public static void main(String[] args) {
        class Plus implements Funktion {
            @Override
            public int fkt(int a, int b) {
                return a + b;
            }
        }
        class Potenz implements Funktion {
            @Override
            public int fkt(int c, int b) {
                if (b <= 0)
                    return 1;
                return c* fkt(c, b-1);
            }
        }
        
        Funktion h = new Potenz();
        perform(new Plus(), 10);
        perform(h, 10);
        
        
        Funktion t = new Funktion() {
                        public int fkt(int a, int b) {
                            return a + b;
                        }
                    };
        perform(t, 10);
        
        
        perform(new Funktion() {
                    public int fkt(int a, int b) {
                        return a + b;
                    }
                }
            , 10);
        perform(new Funktion() {
                    public int fkt(int a, int b) {
                        if (b <= 0)
                            return 1;
                        return a * fkt(a, b-1);
                    }
                }
            , 10);
        
        
        Funktion k = (int a, int b) -> { 
            return a + b;
        };
        k.fkt(5, 4);
        perform(k, 10);
        
        
        Funktion p = (c, b) -> c + b;
        perform(p, 10);
        
        perform((c, b) -> c + b, 10);
        perform(() -> System.out.println("Hi"));
        
        
        
        class MyRunnable implements Runnable {
            @Override
            public void run() {
                System.out.println("Thread läuft");
            }
        }
        Runnable r = new MyRunnable();
        Thread m = new Thread(r);
        m.start();
        
        
        Runnable r2 = new Runnable(){
            @Override
            public void run() {
                System.out.println("Thread läuft");
            }
        };
        Thread m2 = new Thread(r2);
        m2.start();
        
        
        Thread m3 = new Thread(
                new Runnable() {
                    @Override
                    public void run() {
                        System.out.println("Thread läuft");
                    }
                }
        );
        m3.start();
        
        
        Thread m4 = new Thread(() -> System.out.println("Thread läuft"));
        m4.start();
    }
    
    public static void perform(Funktion f, int n) {
        for (int i = 1; i < n; i++) {
            System.out.println(f.fkt(i, i));
        }
    }
    
    public static void perform(Doit d) {
        d.doit();
    }
}