RWIterator Class Reference

Contains virtual functions for positioning and resetting the iterator. More...

#include <rw/iterator.h>

Inheritance diagram for RWIterator:

Public Member Functions
virtual RWCollectable *	findNext (const RWCollectable *target)=0
virtual RWCollectable *	key () const =0
virtual RWCollectable *	operator() ()=0
virtual void	reset ()=0

Detailed Description

Class RWIterator is an abstract base class for iterators used by the Smalltalk-like collection classes. The class contains virtual functions for positioning and resetting the iterator. They are all pure virtual functions, meaning that deriving classes must supply a definition. The descriptions below are intended to be generic – all inheriting iterators generally follow the described pattern.

Synopsis

#include <rw/iterator.h>
(Abstract base class)

Persistence

None

Member Function Documentation

findNext()

virtual RWCollectable * RWIterator::findNext ( const RWCollectable * target )

pure virtual

Moves the iterator forward to the next item which "matches" the object pointed to by target and returns it or rwnil if no item was found. For most collections, an item "matches" the target if either RWCollectable::isEqual() or RWCollectable::compareTo() indicate equivalence, whichever is appropriate for the actual collection type. However, when an iterator is used with an "identity collection" (i.e., RWIdentitySet and RWIdentityDictionary), it looks for an item with the same address (i.e., "is identical to").

Implemented in RWBagIterator, RWBinaryTreeIterator, RWDlistCollectablesIterator, RWHashDictionaryIterator, RWHashTableIterator, RWOrderedIterator, and RWSlistCollectablesIterator.

key()

virtual RWCollectable * RWIterator::key ( ) const

pure virtual

Returns the item at the current iterator position.

Implemented in RWBagIterator, RWBinaryTreeIterator, RWDlistCollectablesIterator, RWHashDictionaryIterator, RWHashTableIterator, RWOrderedIterator, and RWSlistCollectablesIterator.

operator()()

virtual RWCollectable * RWIterator::operator() ( )

pure virtual

Advances the iterator and returns the next item, or rwnil if the end of the collection has been reached.

Implemented in RWBagIterator, RWBinaryTreeIterator, RWDlistCollectablesIterator, RWHashDictionaryIterator, RWHashTableIterator, RWOrderedIterator, and RWSlistCollectablesIterator.

reset()

virtual void RWIterator::reset ( )

pure virtual

Resets the iterator to the state it had immediately after construction.

Implemented in RWBagIterator, RWBinaryTreeIterator, RWDlistCollectablesIterator, RWHashDictionaryIterator, RWHashTableIterator, RWOrderedIterator, RWSetIterator, and RWSlistCollectablesIterator.