RWSequenceable(3C++)

Name
     RWSequenceable - Rogue Wave library class

Synopsis
              #include <rw/seqcltn.h>



              typedef RWSequenceable SequenceableCollection;
                        // Smalltalk typedef




Description
     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.

Persistence
     Polymorphic





Public Member Functions
              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.