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From: "Martin Dowie" <martin.dowie@gecm.com>
Newsgroups: comp.lang.ada
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 <3A753496.67442B90@praxis-cs.co.uk> <955n83$cjr$1@nnrp1.deja.com>
Subject: Re: Computation of exception handling
Date: Tue, 30 Jan 2001 09:15:27 -0000
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Date: 2001-01-30T09:15:27+00:00
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so could the following template be described as 'safe'? i.e. limit the
'allowable' use of exceptions situation where they never propagate?

procedure blah (value : out <some_type>; successful : out boolean) is
  -- exceptions not allowed here
begin
  -- exceptions allowed from here
  successful := true;
  -- exceptions not allowed from here
exception
  when <exception_name> =>
    -- exceptions not allowed here
    value := <known_safe value>
    successful := false;
end blah;

Robert Dewar <robert_dewar@my-deja.com> wrote in message
news:955n83$cjr$1@nnrp1.deja.com...
> In article <3A753496.67442B90@praxis-cs.co.uk>,
>   Peter Amey <pna@praxis-cs.co.uk> wrote:
> > One of the main reasons SPARK does not support exceptions is
> > that we wanted a language free from implementation
> > dependencies.
>
> I don't see any unsurmountable obstacle in defining extensions
> to SPARK that would allow exceptions to be raised without
> creating any implementation defined unknown situations. Yes
> you would have to limit what can be done in exception handlers,
> but SPARK is in the business of figuring out appropriate
> restrictions :-)
>
>
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> http://www.deja.com/