MyMathUtils.java

package vn.nvanhuong.hellojava.java8inaction;

import java.util.stream.IntStream;

public class MyMathUtils {

	public static void main(String[] args) {
		primes(numbers());
	}

	static IntStream numbers() {
		return IntStream.iterate(2, n -> n + 1);
	}

	static int head(IntStream numbers) {
		return numbers.findFirst().getAsInt();
	}

	static IntStream tail(IntStream numbers) {
		return numbers.skip(1);
	}

	static IntStream primes(IntStream numbers) { 
		int head = head(numbers);
		return IntStream.concat(IntStream.of(head),
			primes(tail(numbers).filter(n -> n % head != 0)) );
	}

}