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From: Simon Wright <simon@pushface.org>
Newsgroups: comp.lang.ada
Subject: Re: Problem with Booch iterators
Date: 09 Nov 2002 19:43:10 +0000
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porton@ex-code.com (Victor Porton) writes:

> There are a serious misdesign of Booch iterators:
> 
> Declaring a record component of type Iterator'Class,
> I get error "unconstrained subtype in component declaration".
> 
> So for every non-abstract collection type, a concrete iterator
> type should be visibly declared. It also suggests that types of
> arguments of subrountines should be changed from Iterator'Class
> to the appropriate concrete types.
> 
> Simon, why you've used Iterator'Class everywhere?

Given the way the BC iterators work, I don't know what good having
iterators in records is going to do you.

I don't like the idea of unbound iterators floating around (I suppose
though it's no worse than a Text_IO.File_Type).

I guess I don't see what it is you're trying to do with the BCs that
is causing you so much grief.

Since there are at least 3 projects using the BCs to earn themselves
money (even if I don't see any of it, except indirectly) I won't make
backwards-incompatible changes; and I'm reluctant to add operations
and features, unless it can be done in a way which doesn't increase
the footprint. I would be more inclined to remove things .. BC_Lite, I
guess.