// Example 143 from page 113

//

import java.util.ArrayList;

import java.util.Iterator;

import java.util.List;

import java.util.NoSuchElementException;

import java.util.function.IntUnaryOperator;

import java.util.stream.IntStream;

class Example143 {

public static void main(String[] args) {

for (int i : fromTo(13, 17))

System.out.println(i);

for (int i : fromToStream(13, 17))

System.out.println(i);

List<IntUnaryOperator> functions = new ArrayList<>();

for (int i : fromTo(13, 17))

functions.add(j -> j * i);

for (IntUnaryOperator f : functions)

System.out.println(f.applyAsInt(10));

}

public static Iterable<Integer> fromTo(final int m, final int n) {

class FromToIterator implements Iterator<Integer> {

private int i = m;

public boolean hasNext() { return i <= n; }

public Integer next() {

if (i <= n)

return i++;

else

throw new NoSuchElementException();

}

public void remove() { throw new UnsupportedOperationException(); }

}

class FromToIterable implements Iterable<Integer> {

public Iterator<Integer> iterator() {

return new FromToIterator();

}

}

return new FromToIterable();

}

public static Iterable<Integer> fromToStream(final int m, final int n) {

return () -> IntStream.rangeClosed(m, n).iterator();

}

}