gnu.trove.impl.hash

Class THashIterator<V>

  • All Implemented Interfaces:
    TIterator, Iterator<V>
    Direct Known Subclasses:
    TObjectHashIterator 

    public abstract class THashIterator<V>
extends Object
implements TIterator, 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

      Fields

      Modifier and Type Field and 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 traverses
      protected int _index
      the index used for iteration.

    • Constructor Summary

      Constructors

      Modifier Constructor and Description
      protected THashIterator(TObjectHash<V> hash)
      Create an instance of THashIterator over the values of the TObjectHash

    • Method Summary

      Modifier and Type Method and 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.

    • 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  Iterator<V>
        Returns:
        a boolean 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.

      • moveToNextIndex

        protected final void moveToNextIndex()
        Sets the internal index so that the `next' object can be returned.

      • 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:
        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