Re: GUI was Re: why Ada is so unpopular ?

["Warren W. Gay VE3WWG" <warren@ve3wwg.tk>]

amado.alves wrote:

> <<...this doesn't work very well when you drop
> into a directory with thousands of files. A smart tree widget
> might just peruse "directory portions", where the tree widget
> is visible (perhaps a less than trivial exercise). But I suspect
> they take the easy way out, and require all entries to be loaded
> in to the widget's dynamic memory...>>
> 
> A solution to this is to have and use standard iterator signatures, defined e.g. as formal packages descendants of Ada.Containers. (As an iterator is clearly an item of container design, iterator signatures belong there.)

(BTW, you need to word wrap your responses. When not wrapped
to a reasonable line length, they are difficult to read and
edit).

There are several implementations that can address the performance
issue when it comes to the widget. I am not so easily convinced
that this is possible for a container of "entries". Unless the
O/S can tell you without an exhaustive search of the directory,
how many "entries" you have, some of that same overhead is
still there (memory is excluded, but the reading + counting
of directory entries is still there).

So I don't disagree on theoretical grounds, but in practice
I don't think this would work well.
-- 
Warren W. Gay VE3WWG
http://ve3wwg.tk