Package gnu.trove.impl.hash
Class THashIterator<V>
- java.lang.Object
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- gnu.trove.impl.hash.THashIterator<V>
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- 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.
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Field Summary
Fields Modifier and Type Field Description 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 traversesprotected int
_index
the index used for iteration.
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Constructor Summary
Constructors Modifier Constructor Description protected
THashIterator(TObjectHash<V> hash)
Create an instance of THashIterator over the values of the TObjectHash
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Method Summary
All Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description 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.
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Field Detail
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_hash
protected final THash _hash
the data structure this iterator traverses
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_expectedSize
protected int _expectedSize
the number of elements this iterator believes are in the data structure it accesses.
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_index
protected int _index
the index used for iteration.
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Constructor Detail
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THashIterator
protected THashIterator(TObjectHash<V> hash)
Create an instance of THashIterator over the values of the TObjectHash- Parameters:
hash
- the object
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Method Detail
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next
public V next()
Moves the iterator to the next Object and returns it.- Specified by:
next
in interfacejava.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.
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hasNext
public boolean hasNext()
Returns true if the iterator can be advanced past its current location.
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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.
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moveToNextIndex
protected final void moveToNextIndex()
Sets the internal index so that the `next' object can be returned.
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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.
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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
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