de.unkrig.commons.util.collections

Class IteratorUtil

java.lang.Object

de.unkrig.commons.util.collections.IteratorUtil

public final class IteratorUtil
extends Object

Various Iterator-related utility methods.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	IteratorUtil.ArrayIterator<T> An Iterator that has a notion of an "array index", which is the index of the "next" element in an array.

Field Summary

Fields

Modifier and Type	Field and Description
static Iterator	AT_END An iterator which is at its end.

Method Summary

Modifier and Type	Method and Description
static <T> Iterator<T>	atEnd()
static int	elementCount(Iterator<Integer> iterator) Retrieves, counts and discards all elements remaining on the iterator
static <T> Iterator<T>	filter(Iterator<? extends T> delegate, PredicateWhichThrows<? super T,? extends RuntimeException> qualifies) Returns an iterator which skips the elements of the delegate which do not qualifiy.
static <T> IteratorUtil.ArrayIterator<T>	iterator(T[] array)
static <T> Iterator<T>	repeat(int n, T value)
static <T> Iterator<T>	repeat(T value)
static <I,O> Iterator<O>	transform(Iterator<? extends I> delegate, Transformer<? super I,? extends O> transform) Returns an iterator which iterates the transformed elements of the delegate

Methods inherited from class java.lang.Object

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

Field Detail

AT_END

public static final Iterator AT_END

An iterator which is at its end.

To get the non-rawe type, use atEnd().

Method Detail

atEnd

public static <T> Iterator<T> atEnd()

Returns:

An Iterator which is always at its end

filter

public static <T> Iterator<T> filter(Iterator<? extends T> delegate,
                                     PredicateWhichThrows<? super T,? extends RuntimeException> qualifies)

Returns an iterator which skips the elements of the delegate which do not qualifiy.

transform

public static <I,O> Iterator<O> transform(Iterator<? extends I> delegate,
                                          Transformer<? super I,? extends O> transform)

Returns an iterator which iterates the transformed elements of the delegate

repeat

public static <T> Iterator<T> repeat(T value)

Returns:

An iterator that produces an infinite sequence of value elements

repeat

public static <T> Iterator<T> repeat(int n,
                                     T value)

Returns:

An iterator that produces a sequence of n value elements

iterator

public static <T> IteratorUtil.ArrayIterator<T> iterator(T[] array)

Returns:

An iterator over the elements of the array

elementCount

public static int elementCount(Iterator<Integer> iterator)

Retrieves, counts and discards all elements remaining on the iterator