RWConstIterator Class Reference

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

#include <rw/iterator.h>

Inheritance diagram for RWConstIterator:

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

Detailed Description

Class RWConstIterator is an abstract base class for const iterators used by the Smalltalk-like collection classes. The const iterators do not change any information in the data structure upon which they iterate.

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 const RWCollectable * RWConstIterator::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() indicates 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 RWBagConstIterator, RWBinaryTreeConstIterator, RWDlistCollectablesConstIterator, RWHashDictionaryConstIterator, RWHashTableConstIterator, RWOrderedConstIterator, and RWSlistCollectablesConstIterator.

key()

virtual const RWCollectable * RWConstIterator::key ( ) const

pure virtual

Returns the item at the current iterator position.

Implemented in RWBagConstIterator, RWBinaryTreeConstIterator, RWDlistCollectablesConstIterator, RWHashDictionaryConstIterator, RWHashTableConstIterator, RWOrderedConstIterator, and RWSlistCollectablesConstIterator.

operator()()

virtual const RWCollectable * RWConstIterator::operator() ( )

pure virtual

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

Implemented in RWBagConstIterator, RWBinaryTreeConstIterator, RWDlistCollectablesConstIterator, RWHashDictionaryConstIterator, RWHashTableConstIterator, RWOrderedConstIterator, and RWSlistCollectablesConstIterator.

reset()

virtual void RWConstIterator::reset ( )

pure virtual

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

Implemented in RWBagConstIterator, RWBinaryTreeConstIterator, RWDlistCollectablesConstIterator, RWHashDictionaryConstIterator, RWHashTableConstIterator, RWOrderedConstIterator, RWSetConstIterator, and RWSlistCollectablesConstIterator.