Lambda 几个函数式接口

    // predicat.test 输出 true false
    public static <T> List<T> Filter(List<T> list, Predicate<T> p){
        List<T> result = new ArrayList<T>();
        for (T t : list) {
            if (p.test(t)) {
                result.add(t);
            }
        }
        return result;
    }
    
    // consume.accept 返回值 void
    public static <T> void foeach(List<T> list, Consumer<T> c){
        for (T t : list) {
            c.accept(t);
        }
    }
    
    // function.apply  输入 T 返回 R
    public static <T,R> List<R> Map(List<T> list, Function<T, R> f){
        List<R> result = new ArrayList<>();
        for (T t : list) {
            result.add(f.apply(t));
        }
        return result;
        
    }


@FunctionalInterface
public interface Supplier<T> {

    /**
     * Gets a result.
     *
     * @return a result
     */
    T get();
}