org.vishia.util

Class IteratorMask<T>

java.lang.Object

org.vishia.util.IteratorMask<T>

Type Parameters:

T -

All Implemented Interfaces:

java.lang.Iterable<T>, java.util.Iterator<T>, IterableIterator<T>

public class IteratorMask<T>
extends java.lang.Object
implements IterableIterator<T>

This class helps to iterate ove a given Iterable can be an array, list etc but with a given mask. All non mask elements are not returned. The mask has 64 bits. It means the size is delimited to 64.

Since:

2024-07-14 also an array is Iterable, using IteratorMask(Object[], long).

Field Summary

Fields

Modifier and Type	Field and Description
private T[]	array
(package private) boolean	bExecHasNext
private T	elem
private java.util.Iterator<T>	iterSrc
private int	ix
private long	mask

Constructor Summary

Constructors

Constructor and Description
IteratorMask(java.lang.Iterable<T> iterSrc, long mask)
IteratorMask(java.util.Iterator<T> iteratorSrc, long mask) Initializes with given mask.
IteratorMask(T[] array, long mask)

Method Summary

Modifier and Type	Method and Description
static int	getNextAssocIx(int ix, long mask) Gets the next ix of a set bit in the mask starting from given For example if the mask is 0x21 then the first call getNextAssocIx(-1) returns 0, the next call getNextAssocIx(0) returns 5, and the last call getNextAssocIx(5) returns then -1.
boolean	hasNext()
java.util.Iterator<T>	iterator()
T	next()

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Iterator

forEachRemaining, remove

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Field Detail

ix

private int ix

iterSrc

private final java.util.Iterator<T> iterSrc

array

private final T[] array

elem

private T elem

mask

private final long mask

bExecHasNext

boolean bExecHasNext

Constructor Detail

IteratorMask

public IteratorMask(java.util.Iterator<T> iteratorSrc,
                    long mask)

Initializes with given mask.

Parameters:

array - Any array with proper type

mask - selection which elements should be returned 1-of-64

IteratorMask

public IteratorMask(java.lang.Iterable<T> iterSrc,
                    long mask)

IteratorMask

public IteratorMask(T[] array,
                    long mask)

Method Detail

hasNext

public boolean hasNext()

Specified by:

hasNext in interface java.util.Iterator<T>

next

public T next()

Specified by:

next in interface java.util.Iterator<T>

iterator

public java.util.Iterator<T> iterator()

Specified by:

iterator in interface java.lang.Iterable<T>

getNextAssocIx

public static int getNextAssocIx(int ix,
                                 long mask)

Gets the next ix of a set bit in the mask starting from given For example if the mask is 0x21 then the first call getNextAssocIx(-1) returns 0, the next call getNextAssocIx(0) returns 5, and the last call getNextAssocIx(5) returns then -1.

Parameters:

ix - given ix, should start with -1 to detect 0 as first one

Returns:

0..63 for given, or -1 if nothing more found.