Re: Ada Core Technologies and Ada95 Standards

[Mike Young <mikey@mcs.com>]

Robert Dewar wrote:
> 
> iJohn McCabe said
> 
> "`` I was obviously thinking of validation of Ada compilers in the same
>    way that _my_ software is validated - i.e a full set of test cases
>    proving that _all_ requirements have been met. ''"
> 
> I and others pointed out that this is obviously false for complex
> software of any kind. If John really thinke he can provide this
> proof via test cases, he is deluding himself (and his clients).
> 
> What is more interesting is that even a VERY simple program cannot
> be provied by simple input-output tests. Consider the following
> program to add the numbers from 1 to 10.
> 
> with Text_IO; use Text_IO;
> 
> procedure s is
>    sum : integer;
> begin
>    for j in 1 .. 10 loop
>       sum := sum + j;
>    end loop;
> 
>    Put_Line (Integer'Image (j));
> end;
> 
> this works fine on my machine. exhaustive testing (one case!!) proves
> that it works, but of course it has a fatal problem, and may not work
> tomorrow

=======
I don't see the connection... Are you saying validation is 
happen-stance, that the brightest minds can't come up with a test suite 
to test all expected behavior? Your "test" seems reasonable enough to 
validate that integer var's are initialized to zero by default; ehhh, at 
least the few times you ran the test case...

Mike.