Re: How do I write directly to a memory address?

[Hyman Rosen <hyrosen@mail.com>]

On 2/9/2011 5:38 PM, Vinzent Hoefler wrote:
> Hyman Rosen wrote:
>
>> Excuse me, but I really, truly do need to know what my
>> subprogram is going to do. People have been telling me
>> about "contracts" and "requirements" and "proofs of
>> correctness" and that Ada is good for stuff. So I have
>> this subprogram and I'd like to know what it will do
>> for different values of its parameter so I'll know if
>> I can use it or not.
>
> You can't use it. It will raise Storage_Error for some
> values.

Hmm. You know, this makes me think that before I can call
any subprogram, I'm going to need to examine its body to
see how many nested subprogram calls it makes, as well as
those bodies, and so on. And even then, is there anything
that tells me exactly when I will get Storage_Error? How
can I reason about the behavior of any Ada program?

OK, I know I'm sounding like a smart ass, but take my
question seriously. There's an awful lot of castigation
of C code (and coders) going on here, with complaints
about "bugs on every line", but isn't that equally true
of Ada code? Doesn't every subprogram call potentially
raise Storage_Error, and isn't that possibility usually
ignored? And in fact, don't Ada newbies run into this
all the time, because they declare large arrays or
records as local variables and run out the call stack?