[plt-scheme] to define, or to let

Matthias Felleisen <matthias at ccs.neu.edu> writes:

> On Mar 23, 2004, at 10:45 AM, Joe Marshall wrote:
>
>> Do you care which OS error terminates your program?
>
> Of course, the more information you have about errors the better. I
> don't know about you but it helps me debug my programs.

My point (obviously) is that there is no information there.

By specifiying a fixed order of evaluation, you prohibit an
implementation from providing information that could be obtained by
varying the order of execution.  So don't you want this?

>> I would *love* to have a Scheme system that could continue
>> as if nothing had happened even in the presence of the most obvious
>> errors.
>
> Okay, so -- as your boss -- I want you to imagine for a day that no
> error message ever shows up, that they all calls to error (external
> and internal) are replaced with
>
>   (random-pick '(... your favorite 100 Scheme values from the running
> program ...))
>
> and off you go. -- Matthias

But that system will continue as if a random value had been
substituted, not as if the error did not occur.  You promised the
latter.