[clean-list] IEEE floating point and Clean

[Marco Kesseler]

> As I understand Kahan now. He wants that a computation doesn't interrupt
> but the user should get the possibility to set a flag do work off the
> place where the infinity/over/underflow... occured.
> 
> An obtuse question: Why isn't this possible with Clean or are there any
> well planed reasons to implement Clean as it is now? It is likely that
> the Clean guys were aware of exception-handling.

Yes, I know they were, but exceptions (a la Java) in a pure, lazy 
functional language is not an easy thing to implement, to put it 
mildly.

It IS possible to create your own floating point numbers in Clean, 
an attach flags to them. Various operations on these numbers 
should then test their results for 'INF' and the like, and set the 
flags. Users of these numbers can then check whether something 
went wrong in the computation of some result.

Kahan however would like support for this in the language itself, 
because this could avoid performce problems (which are usually 
important in computations that involve floating points).
 
> Clean team, please do not get depressed, I still like Clean. But I think
> some themes are not discussed or unspoken and this could make confusion.
> You may not forget, there are a hundred of "silent" readers who maybe
> get a wrong impression.

In this respect, Clean is certainly not worse than most of the 
'commercial' languages.

regards,
Marco

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