Re: OO Style with Ada Containers

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On Mon, 19 Nov 2007 12:45:12 -0800 (PST), Maciej Sobczak wrote:

> On 19 Lis, 17:19, "Dmitry A. Kazakov" <mail...@dmitry-kazakov.de>
> wrote:
> 
>>> Consider a virtual iterator that does not have
>>> *any* container behind, but can serve as a sequence generator. And so
>>> on.
>>
>> An iterator always has a container behind (a class of containers actually).
>> If you generate just a sequence, where do you know the mapping of the
>> sequence onto the elements of a container?
> 
> Why should I bother with mapping the sequence onto the container if
> there is no container?

Because the sequence will be later used with a container. And not to
forget, a sequence itself is a container. It is an ordered set of elements.

> This is not each second element. This is a sequence 2,4,6,8 (but it
> really does not make any difference).

Of course it does. Because in an ordered set you can query for the next
element of. Is Succ (2) = 4?

You cannot "take" values as they are. There is no values without types of.
 
> Now consider an iterator generating a (samples of) sine wave with
> given parameters. Infinitely! It plays a sound using attached DAC.

> There is no container behind. Just a sequence.

This is a totally wrong analogy with many more things assumed, than just a
container.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de