Re: OO Style with Ada Containers

[Georg Bauhaus <rm.tsoh+bauhaus@maps.futureapps.de>]

On Tue, 2007-11-20 at 06:11 -0800, Maciej Sobczak wrote:

> Two points:
> 
> 1.
> The most important part of STL is the notion of range-based iteration.
...
> Ada.Containers does not support anything like this.

I think Ada containers do support range-based iteration.
In fact, the Floor and Ceiling operations of ordered maps
(similar to C++ STL's lower_bound() and upper_bound())
will give you a cursor, and the Cursor's interface includes
"/=" ...

>  The only available
> algorithms work on whole containers.

That, again, is the algorithm question, isn't it? You get two
cursors, do something with them. For example, feed them to
a generic sum. Some algorithms can be found in the Charles
library (<= AI302, <= Ada.Containers).

http://charles.tigris.org


> 2.
> Another important part of STL is the notion of iterator category.
> Depending on the category, the iterator can support different sets of
> operations. The most powerful is RandomAccessIterator, which allows to
> arbitrarily jump around the sequence in constant time.

This particular case can be handled using Vector's Extended_Index
subtype,
" because vector 
  itself is inherently random-accessible."
To the extent that Extended_Index does not establish iterator
categories.