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From: "Randy Brukardt" <randy@rrsoftware.com>
Newsgroups: comp.lang.ada
Subject: Re: Ada 'hello world' for Android; success!
Date: Mon, 31 Oct 2011 17:34:48 -0500
Organization: Jacob Sparre Andersen Research & Innovation
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Date: 2011-10-31T17:34:48-05:00
List-Id: <comp.lang.ada>

"Stephen Leake" <stephen_leake@stephe-leake.org> wrote in message 
news:82mxciogt0.fsf@stephe-leake.org...
...
> In brief, _any_ framework that uses dispatching on class-wide
> objects needs reference semantics. In Ada, that is indicated by the
> explicit word 'access'. In Java, it is implicit. I prefer explicit.

I don't follow this. All tagged objects in Ada are by-reference, so you 
never need explicit "access" for parameter passing. And class-wide objects 
can be stored in the Ada containers without using "access" as well.

Claw is a framework that uses dispatching and reference semantics, yet it 
almost never uses explicit "access". So to claim it can't be done is 
disingenious.

The problem with "access" in Ada is that it puts all of the burden of the 
storage management on the user, and it locks the user out of using the 
containers for storage management (as well as making stack-based object 
management much more wordy). It's much better to put that burden on the Ada 
implementation, and to give the clients maximum flexibility in how to 
structure their programs.

                             Randy.