gnu.trove.impl.hash
Class THashIterator<V>

java.lang.Object
  gnu.trove.impl.hash.THashIterator<V>

All Implemented Interfaces:

TIterator, java.util.Iterator<V>

Direct Known Subclasses:

TObjectHashIterator

public abstract class THashIterator<V>
extends java.lang.Object
implements TIterator, java.util.Iterator<V>

Implements all iterator functions for the hashed object set. Subclasses may override objectAtIndex to vary the object returned by calls to next() (e.g. for values, and Map.Entry objects).

Note that iteration is fastest if you forego the calls to hasNext in favor of checking the size of the structure yourself and then call next() that many times:

 Iterator i = collection.iterator();
 for ( int size = collection.size(); size-- > 0; ) {
        Object o = i.next();
 }
 

You may, of course, use the hasNext(), next() idiom too if you aren't in a performance critical spot.

Field Summary

protected int	_expectedSize the number of elements this iterator believes are in the data structure it accesses.
protected THash	_hash the data structure this iterator traverses
protected int	_index the index used for iteration.

Constructor Summary

protected

THashIterator(TObjectHash<V> hash) Create an instance of THashIterator over the values of the TObjectHash

Method Summary

boolean	hasNext() Returns true if the iterator can be advanced past its current location.
protected void	moveToNextIndex() Sets the internal index so that the `next' object can be returned.
V	next() Moves the iterator to the next Object and returns it.
protected int	nextIndex() Returns the index of the next value in the data structure or a negative value if the iterator is exhausted.
protected abstract V	objectAtIndex(int index) Returns the object at the specified index.
void	remove() Removes the last entry returned by the iterator.

Methods inherited from class java.lang.Object

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

Field Detail

_hash

protected final THash _hash

the data structure this iterator traverses

_expectedSize

protected int _expectedSize

the number of elements this iterator believes are in the data structure it accesses.

_index

protected int _index

the index used for iteration.

Constructor Detail

THashIterator

protected THashIterator(TObjectHash<V> hash)

Create an instance of THashIterator over the values of the TObjectHash

Parameters:

hash - the object

Method Detail

hasNext

public boolean hasNext()

Returns true if the iterator can be advanced past its current location.

Specified by:

hasNext in interface TIterator

Specified by:

hasNext in interface java.util.Iterator<V>

Returns:

a boolean value

moveToNextIndex

protected final void moveToNextIndex()

Sets the internal index so that the `next' object can be returned.

next

public V next()

Moves the iterator to the next Object and returns it.

Specified by:

next in interface java.util.Iterator<V>

Returns:

an Object value

Throws:

java.util.ConcurrentModificationException - if the structure was changed using a method that isn't on this iterator.

java.util.NoSuchElementException - if this is called on an exhausted iterator.

nextIndex

protected final int nextIndex()

Returns the index of the next value in the data structure or a negative value if the iterator is exhausted.

Returns:

an int value

Throws:

java.util.ConcurrentModificationException - if the underlying collection's size has been modified since the iterator was created.

objectAtIndex

protected abstract V objectAtIndex(int index)

Returns the object at the specified index. Subclasses should implement this to return the appropriate object for the given index.

Parameters:

index - the index of the value to return.

Returns:

an Object value

remove

public void remove()

Removes the last entry returned by the iterator. Invoking this method more than once for a single entry will leave the underlying data structure in a confused state.

Specified by:

remove in interface TIterator

Specified by:

remove in interface java.util.Iterator<V>