[clean-list] Clean in the Real World

[Marco Kesseler]

>On 15-Dec-2003, Arjen van Weelden <arjenw@cs.kun.nl> wrote:
>> As I see it, catching exceptions is only non-deterministic between 
>> compilations.
>
>You may see it that way, and it might perhaps even be true for the
>current Clean implementation, but that's not the case in general.
>IMHO imposing that as a requirement would unduly restrict the
>compiler's freedom to optimize code.

As long as it optimises at compile time, it is free to do whatever it 
wants, except at a few locations that hold catch statements.

>It would rule out or significantly restrict important categories of
>implementations, including those that do automatic parallelization,
>and those that initially evaluate code naively and then apply
>optimizations based on run-time profiling feedback.

As soon as we get these, I am willing to think about other ways to 
deal with exceptional situations.

Apart from that, the same non-deterministic effects will occur in the 
Monadic solution. The fact that this is theoretically allowed may not 
help the average programmer in reasoning about his program.

(which does _not_ imply that I am against soundness)

And then, there is still the possibility to enforce catch statements 
to always deliver the same constant expression on any exception.

>-- 
>Fergus Henderson <fjh@cs.mu.oz.au>  |  "I have always known that the pursuit
>The University of Melbourne         |  of excellence is a lethal habit"
>WWW: <http://www.cs.mu.oz.au/~fjh>  |     -- the last words of T. S. Garp.
>
>
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