org.eclipse.xtext.xbase.lib

Class ExclusiveRange

java.lang.Object

org.eclipse.xtext.xbase.lib.ExclusiveRange

All Implemented Interfaces:

java.lang.Iterable<java.lang.Integer>

@GwtCompatible
public class ExclusiveRange
extends java.lang.Object
implements java.lang.Iterable<java.lang.Integer>

A sequence of integers starting from start to end counting up or down. It excludes the end value when counting up and the start value when counting down. Examples:

new ExclusiveRange(1, 5, true)	(1,2,3,4)
new ExclusiveRange(0, 0, true)	()
new ExclusiveRange(0, -1, true)	()
new ExclusiveRange(-1, 0, true)	(-1)
new ExclusiveRange(5, 1, false)	(4,3,2,1)
new ExclusiveRange(0, 0, false)	()
new ExclusiveRange(-1, 0, false)	()
new ExclusiveRange(0, -1, false)	(-1)

As opposed to IntegerRange this class meets the requirements to iterate arrays or lists without the need for further guards, e.g.

 for(i: new ExclusiveRange(0, list.size, true)) 
   list.get(i)...
 
 for(i: new ExclusiveRange(array.length, 0, false)) 
   array.get(i)...
 
 for(i: new ExclusiveRange(0, string.indexOf('x'), true)
   string.charAt(i)...
 

Since:

2.4

Author:

Jan Koehnlein - Initial contribution and API

Constructor Summary

Constructors

Constructor and Description
ExclusiveRange(int start, int end, boolean increment) Constructs a new ExclusiveRange object.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	contains(int number) Checks whether this contains the given number, i.e.
boolean	isEmpty() Returns whether this is range is empty.
java.util.ListIterator<java.lang.Integer>	iterator()
int	size() Returns the number of elements in this ExclusiveRange.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ExclusiveRange

@Pure
public ExclusiveRange(int start,
                   int end,
                   boolean increment)

Constructs a new ExclusiveRange object.

Parameters:

start - the start value

end - the end value

increment - if true, the range goes from start up to end (exclusive) if false, the range goes from end down to start (exclusive)

Method Detail

iterator

@Pure
public java.util.ListIterator<java.lang.Integer> iterator()

Specified by:

iterator in interface java.lang.Iterable<java.lang.Integer>

Returns:

a read-only ListIterator for this.

size

@Pure
public int size()

Returns the number of elements in this ExclusiveRange.

Returns:

the number of elements in this ExclusiveRange.

isEmpty

@Pure
public boolean isEmpty()

Returns whether this is range is empty.

Returns:

true if this range is empty.

contains

@Pure
public boolean contains(int number)

Checks whether this contains the given number, i.e. whether the iterator will yield the number. This is different from interval containment: 0..2.by(2) will not contain 1.

Parameters:

number - the number to be checked for containment.

Returns:

whether this sequence contains the given number or not.