Mega Code Archive
Integer Sequence Generator
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//package org.hh.jga.util;
import java.util.Iterator;
/**
* Integer Sequence Generator
*
* @author Hong Hong
*
*/
public abstract class Range<T extends Number> implements Iterable<T> {
public static Range<Integer> range(int from, int to, int step) {
return new IntRange(from, to, step);
}
public static Range<Integer> range(int from, int to) {
return new IntRange(from, to, to >= from ? 1 : -1);
}
public static Range<Integer> range(int to) {
return new IntRange(0, to, 1);
}
public static Range<Short> range(short from, short to, short step) {
return new ShortRange(from, to, step);
}
public static Range<Short> range(short from, short to) {
return new ShortRange(from, to, (short)(to >= from ? 1 : -1));
}
public static Range<Short> range(short to) {
return new ShortRange((short)0, to, (short)1);
}
public static Range<Long> range(long from, long to, long end) {
return new LongRange(from, to, end);
}
public static Range<Long> range(long from, long to) {
return new LongRange(from, to, to >= from ? 1L : -1L);
}
public static Range<Long> range(Long to) {
return new LongRange(0L, to, 1L);
}
protected static class IntRange extends Range<Integer> implements Iterator<Integer> {
protected int m_cur, m_step, m_end;
public IntRange(int from, int to, int step) {
m_cur = from;
m_step = step;
m_end = to;
}
public boolean hasNext() {
return m_step > 0 ? m_cur < m_end : m_end < m_cur;
}
public Integer next() {
int res = m_cur;
m_cur += m_step;
return res;
}
public void remove() {
throw new UnsupportedOperationException();
}
public Iterator<Integer> iterator() {
return this;
}
}
protected static class LongRange extends Range<Long> implements Iterator<Long> {
protected long m_cur, m_step, m_end;
public LongRange(long from, long to, long step) {
m_cur = from;
m_step = step;
m_end = to;
}
public boolean hasNext() {
return m_step > 0 ? m_cur < m_end : m_end < m_cur;
}
public Long next() {
long res = m_cur;
m_cur += m_step;
return res;
}
public void remove() {
throw new UnsupportedOperationException();
}
public Iterator<Long> iterator() {
return this;
}
}
protected static class ShortRange extends Range<Short> implements Iterator<Short> {
protected short m_cur, m_step, m_end;
public ShortRange(short from, short to, short step) {
m_cur = from;
m_step = step;
m_end = to;
}
public boolean hasNext() {
return m_step > 0 ? m_cur < m_end : m_end < m_cur;
}
public Short next() {
short res = m_cur;
m_cur += m_step;
return res;
}
public void remove() {
throw new UnsupportedOperationException();
}
public Iterator<Short> iterator() {
return this;
}
}
}
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