[r6rs-discuss] [Formal] Allow compilers to reject obvious violations

[Arthur A. Gleckler]

On Feb 24, 2007, at 4:54 PM, William D Clinger wrote:

> Matthias Felleisen wrote:
>>   2. Naturally I don't reject type systems per se but I think that  
>> a serious
>>      language definition shouldn't introduce such systems without  
>> specifying
>>      them. Otherwise a language/implementation will appear  
>> whimsical to
>>      programmers.
>
> The current draft already mandates hundreds of runtime
> exceptions whose whimsical purpose is to make programs
> that violate the requirements of the R6RS less likely
> to run to completion.  Why should that kind of whimsy
> be limited to run time?

My only concern is that an error in one part of my program should not  
prevent me from running another part of the program.  The thing I  
most dislike about most statically typed language implementations is  
that they prevent me from testing a program that isn't yet completely  
type-correct when I'm not even planning to invoke the broken part of  
the program.  I suppose that this suggestion only allows, but doesn't  
require, compiler writers to signal errors it can detect at compile  
time.  Still, I'd rather not encourage this behavior if it makes it  
impossible to run programs that are not yet completely correct.