groovy.lang.IntRange Maven / Gradle / Ivy
/*
* Copyright 2003-2013 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package groovy.lang;
import org.codehaus.groovy.runtime.IteratorClosureAdapter;
import java.math.BigInteger;
import java.util.AbstractList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
/**
* Represents a list of Integer objects from a specified int up (or down) to and including
* a given to.
*
* This class is a copy of {@link ObjectRange} optimized for int. If you make any
* changes to this class, you might consider making parallel changes to {@link ObjectRange}.
*
* @author James Strachan
* @version $Revision$
*/
public class IntRange extends AbstractList implements Range {
/**
* Iterates through each number in an IntRange.
*/
private class IntRangeIterator implements Iterator {
/**
* Counts from 0 up to size - 1.
*/
private int index;
/**
* The number of values in the range.
*/
private int size = size();
/**
* The next value to return.
*/
private int value = reverse ? to : from;
/**
* {@inheritDoc}
*/
public boolean hasNext() {
return index < size;
}
/**
* {@inheritDoc}
*/
public Integer next() {
if (index++ > 0) {
if (index > size) {
return null;
} else {
if (reverse) {
--value;
} else {
++value;
}
}
}
return Integer.valueOf(value);
}
/**
* Not supported.
*
* @throws java.lang.UnsupportedOperationException
* always
*/
public void remove() {
IntRange.this.remove(index);
}
}
/**
* The first number in the range. from is always less than or equal to to.
*/
private int from;
/**
* The last number in the range. to is always greater than or equal to from.
*/
private int to;
/**
* If false, counts up from from to to. Otherwise, counts down
* from to to from.
*/
private boolean reverse;
/**
* Creates a new IntRange. If from is greater
* than to, a reverse range is created with
* from and to swapped.
*
* @param from the first number in the range.
* @param to the last number in the range.
* @throws IllegalArgumentException if the range would contain more than
* {@link Integer#MAX_VALUE} values.
*/
public IntRange(int from, int to) {
if (from > to) {
this.from = to;
this.to = from;
this.reverse = true;
} else {
this.from = from;
this.to = to;
}
// size() an integer so ranges can have no more than Integer.MAX_VALUE elements
if (this.to - this.from >= Integer.MAX_VALUE) {
throw new IllegalArgumentException("range must have no more than " + Integer.MAX_VALUE + " elements");
}
}
/**
* Creates a new IntRange.
*
* @param from the first value in the range.
* @param to the last value in the range.
* @param reverse true if the range should count from
* to to from.
* @throws IllegalArgumentException if from is greater than to.
*/
protected IntRange(int from, int to, boolean reverse) {
if (from > to) {
throw new IllegalArgumentException("'from' must be less than or equal to 'to'");
}
this.from = from;
this.to = to;
this.reverse = reverse;
}
/**
* Determines if this object is equal to another object. Delegates to
* {@link AbstractList#equals(Object)} if that is anything
* other than an {@link IntRange}.
*
* It is not necessary to override hashCode, as
* {@link AbstractList#hashCode()} provides a suitable hash code.
*
* Note that equals is generally handled by {@link org.codehaus.groovy.runtime.DefaultGroovyMethods#equals(List,List)}
* instead of this method.
*
* @param that the object to compare
* @return true if the objects are equal
*/
public boolean equals(Object that) {
return that instanceof IntRange ? equals((IntRange) that) : super.equals(that);
}
/**
* Compares an {@link IntRange} to another {@link IntRange}.
*
* @param that the object to compare for equality
* @return true if the ranges are equal
*/
public boolean equals(IntRange that) {
return that != null && this.reverse == that.reverse && this.from == that.from && this.to == that.to;
}
/**
* {@inheritDoc}
*/
public Integer getFrom() {
return Integer.valueOf(from);
}
/**
* {@inheritDoc}
*/
public Integer getTo() {
return Integer.valueOf(to);
}
/**
* Gets the 'from' value as an integer.
*
* @return the 'from' value as an integer.
*/
public int getFromInt() {
return from;
}
/**
* Gets the 'to' value as an integer.
*
* @return the 'to' value as an integer.
*/
public int getToInt() {
return to;
}
/**
* {@inheritDoc}
*/
public boolean isReverse() {
return reverse;
}
public boolean containsWithinBounds(Object o) {
return contains(o);
}
/**
* {@inheritDoc}
*/
public Integer get(int index) {
if (index < 0) {
throw new IndexOutOfBoundsException("Index: " + index + " should not be negative");
}
if (index >= size()) {
throw new IndexOutOfBoundsException("Index: " + index + " too big for range: " + this);
}
int value = reverse ? to - index : index + from;
return Integer.valueOf(value);
}
/**
* {@inheritDoc}
*/
public int size() {
return to - from + 1;
}
/**
* {@inheritDoc}
*/
public Iterator iterator() {
return new IntRangeIterator();
}
/**
* {@inheritDoc}
*/
public List subList(int fromIndex, int toIndex) {
if (fromIndex < 0) {
throw new IndexOutOfBoundsException("fromIndex = " + fromIndex);
}
if (toIndex > size()) {
throw new IndexOutOfBoundsException("toIndex = " + toIndex);
}
if (fromIndex > toIndex) {
throw new IllegalArgumentException("fromIndex(" + fromIndex + ") > toIndex(" + toIndex + ")");
}
if (fromIndex == toIndex) {
return new EmptyRange(Integer.valueOf(from));
}
return new IntRange(fromIndex + this.from, toIndex + this.from - 1, reverse);
}
/**
* {@inheritDoc}
*/
public String toString() {
return reverse ? "" + to + ".." + from : "" + from + ".." + to;
}
/**
* {@inheritDoc}
*/
public String inspect() {
return toString();
}
/**
* {@inheritDoc}
*/
public boolean contains(Object value) {
if (value instanceof Integer) {
Integer integer = (Integer) value;
int i = integer.intValue();
return i >= from && i <= to;
}
if (value instanceof BigInteger) {
BigInteger bigint = (BigInteger) value;
return bigint.compareTo(BigInteger.valueOf(from)) >= 0 &&
bigint.compareTo(BigInteger.valueOf(to)) <= 0;
}
return false;
}
/**
* {@inheritDoc}
*/
public boolean containsAll(Collection other) {
if (other instanceof IntRange) {
final IntRange range = (IntRange) other;
return this.from <= range.from && range.to <= this.to;
}
return super.containsAll(other);
}
/**
* {@inheritDoc}
*/
public void step(int step, Closure closure) {
if (step == 0) {
if (from != to) {
throw new GroovyRuntimeException("Infinite loop detected due to step size of 0");
} else {
return; // from == to and step == 0, nothing to do, so return
}
}
if (reverse) {
step = -step;
}
if (step > 0) {
int value = from;
while (value <= to) {
closure.call(Integer.valueOf(value));
value = value + step;
}
} else {
int value = to;
while (value >= from) {
closure.call(Integer.valueOf(value));
value = value + step;
}
}
}
/**
* {@inheritDoc}
*/
public List step(int step) {
IteratorClosureAdapter adapter = new IteratorClosureAdapter(this);
step(step, adapter);
return adapter.asList();
}
}