Click on the banner to return to the Class Reference home page.

©Copyright 1996 Rogue Wave Software

RWSequenceable

RWSequenceableRWCollectionRWCollectable

• Synopsis
• Description
• Persistence
• Public Member Functions

#include <rw/seqcltn.h>

typedef RWSequenceable SequenceableCollection;
              // Smalltalk typedef

Class RWSequenceable is an abstract base class for collections that can be accessed by an index. It inherits class RWCollection as a public base class and adds a few extra virtual functions. This documentation only describes these extra functions.

Polymorphic

RWCollectable*
append(RWCollectable*) = 0;

Adds the item to the end of the collection and returns it. Returns nil if the insertion was unsuccessful.

virtual RWCollectable*&
at(size_t i);
virtual const RWCollectable*
at(size_t i) const;

Allows access to the ith element of the collection. The first variant can be used as an lvalue, the second cannot. The index i must be between zero and the number of items in the collection less one, or an exception of type RWBoundsErr will be thrown.

virtual RWCollectable*
first() const = 0;

Returns the first item in the collection.

virtual size_t
index(const RWCollectable* c) const = 0;

Returns the index number of the first item that "matches" the item pointed to by c. If there is no such item, returns RW_NPOS. For most collections, an item "matches" the target if either isEqual() or compareTo() find equivalence, whichever is appropriate for the actual collection type.

void
insertAt(size_t indx, RWCollectable* e);

Adds a new item to the collection at position indx. The item previously at position i is moved to i+1, etc. The index indx must be between 0 and the number of items in the collection, or an exception of type RWBoundsErr will be thrown.

virtual RWCollectable*
last() const = 0;

Returns the last item in the collection.

RWCollectable*
prepend(RWCollectable*) = 0;

Adds the item to the beginning of the collection and returns it. Returns nil if the insertion was unsuccessful.