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Newsgroups: comp.lang.ada
Date: Wed, 24 Feb 2016 23:55:37 -0800 (PST)
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Subject: Re: Asynchronous channels in Ada
From: Hadrien Grasland <hadrien.grasland@gmail.com>
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Xref: news.eternal-september.org comp.lang.ada:29601
Date: 2016-02-24T23:55:37-08:00
List-Id: <comp.lang.ada>

So, to summarize, what you would suggest is to mimick the layered architect=
ure of network protocols, and separate the task of getting messages across =
from one task to another (which can be handled by any synchronized queue im=
plementation), from that of transmitting either valid data or errors inside=
 of messages.

You would then handle the latter task by using either...

1. Discriminated records that can contain either messages or errors dependi=
ng on the discriminant's value
2. A tagged message interface that is associated to two concrete implementa=
tions, one which carries data and normally returns it upon "opening", and o=
ne which carries errors and throws exceptions in this situation.

That sounds like a very good idea, I'll experiment with it some more. Thank=
s !