Re: Would You Fly an Airplane with a Linux-Based Control System?

[Marius Amado Alves <amado.alves@netcabo.pt>]

Mike Silva wrote:
> Even accepting your assertion that your hypothesis has not been
> disproven, what conclusion do you draw?  That deliberately ignoring
> out-of-range data (not throwing it away, just ignoring it) will
> generally lead to safer systems than dealing with out-of-range data in
> some pre-determined way that may not always be the right choice
> (especially if the system is mis-used in a manner so that out-of-range
> data is suddenly legal)?
> 
> What, again, is your conclusion?

I do not draw a general conclusion. I merely point out that it is 
essential in this particular case to elicit the results of catching vs. 
not catching the exception, and in that context of using an 
"exceptional" language vs. an exceptionless one. Be very aware of 
general conclusions. Again, general expressions like "deliberately 
ignoring out-of-range data (not throwing it away, just ignoring it)" 
just make things worse. Out of what range? What is the difference 
between ignoring and throwing away? If it's data it's processed in some 
way, cannot really be ignored or thrown away can it?