Re: Generic Package

[Simon Wright <simon.j.wright@mac.com>]

"Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> writes:

> This is too swampy. There is a sufficient difference between foreach
> closures and interators. You can have foreach on an unordered set,
> but you cannot have iterators. The difference is in who has the
> control over the enumeration process. Iterators are more binding for
> the container and less for the user of.

Clearly "iterator" means something to you that it doesn't to me.

This is probably not related to the discussions round Ada 05 which led
to the use of the word Cursor instead of Iterator (the BCs use
Iterator for historical reasons, but in a completely different sense
from the STL, which is the basis for Ada.Containers).

> Consider a library. Say you wished to read all books there. You come
> to the librarian and order a book. Then you read that book and
> return. Now, you can ask him: give me another book. But you cannot
> require him to give you a book that you haven't yet read. That is
> your business, he would answer.

I think that's only because readers are a tiresome perturbation in the
librarian's universe!