import java.util.function.*;

import java.util.stream.*;

import static java.util.stream.Collectors.*;

import java.time.*;

public class Functions {

public static void main(String...args) {

Function<Integer,String> f = Function.<Integer>identity()

.andThen(i -> 2*i).andThen(i -> "str" + i);

System.out.println(

Stream.iterate(1, i -> i + 1)

.limit(10)

.map(f)

.collect(joining(","))

);

Function<LocalDate,LocalDateTime> plusTwoM = Function.<LocalDate>identity()

.andThen(dateTimeFunction(d -> d.plusMonths(2)));

System.out.println(

Stream.iterate(LocalDate.now(), d -> d.plusDays(1))

.limit(10)

.map(plusTwoM)

.map(Object::toString)

.collect(joining(", "))

);

}

public static Function<LocalDate,LocalDateTime> dateTimeFunction(

final Function<LocalDate,LocalDate> f) {

return f.andThen(d -> d.atTime(2, 2));

}

}