Re: XML DOM Binding for Ada 95 - matter of style

["Matthew Heaney" <matthewjheaney@earthlink.net>]

"Simon Wright" <simon@pushface.org> wrote in message
news:x7vn0eu4iwc.fsf@smaug.pushface.org...
>
> It's not clear to me that this is a consequence of using tagged
> types?? perhaps .. anyway, what people complain about, until they've
> got used to it or developed a tool to generate the code for them, is
> the instantiating, not the taggedness.

But you have to perform the instantiation because the type you really need
is a derivation.  If there were no derivation (no inheritance), then there
would be no need for the second instantiation and the problem would
disappear.

The other issue is that iteration can only be done using a class-wide type,
which means all operations are dynamically bound.  Not only is this less
efficient, it is unnecessary, because all the types are known statically.

The only time it would make sense to use dynamic binding is if the type of
the container object weren't known until run-time.  But this is very
atypical.

There is also a space penalty, because each iterator object must also carry
a tag, in addition to the internal pointer.