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From: Stephen Leake <Stephen.Leake@gsfc.nasa.gov>
Subject: Re: Icon Co-Expressions in Ada
Date: 1998/12/16
Message-ID: <uzp8n69k2.fsf@gsfc.nasa.gov>#1/1
X-Deja-AN: 423021195
References: 
 <Pine.A41.3.96-heb-2.07.981216194156.29486C-100000@pluto.mscc.huji.ac.il>
Organization: NASA Goddard Space Flight Center -- Greenbelt, Maryland USA
Newsgroups: comp.lang.ada
Date: 1998-12-16T00:00:00+00:00
List-Id: <comp.lang.ada>

Ehud Lamm <mslamm@mscc.huji.ac.il> writes:

> I am thinking about implimenting Goal Directed Evaluation ala Icon, as an
> Ada package. I considred two options:
> 1. Using "static" data (that is, variables stored in the package's body,
> in Ada) to impliment the suspend mechanism. This has its obvious problems.

Since I don't know anything about Icon, can you explain what "the
suspend mechanism" does?

> 2. Using Ada's tasking facilites. This has the disadvantage of making the
> user use tasks. It is sad, since as far as I know you can't simply make an
> Ada procedure behave in a task like way, by invking other procedures. The
> task must be explicit.

If "suspend" has its usual English meaning, the user should be using
tasks; one task is suspended while another is running.

An Ada procedure can call task entries, and task entry bodies can call
procedures. Not clear what else you need.

-- Stephe