Re: status of Ada STL?

[Dmitry A. Kazakov <mailbox@dmitry-kazakov.de>]

On 20 Jun 2002 11:20:44 -0700, 18k11tm001@sneakemail.com (Russ) wrote:

>Dmitry A.Kazakov <mailbox@dmitry-kazakov.de> wrote in message news:<aes7nh$9ar7i$1@ID-77047.news.dfncis.de>...
>> Russ wrote:
>
>> The point is that though a set-theoretic equality might be defined, for 
>> some types it might appear unusable for them, like for floating-points or 
>> fuzzy sets. For other things it cannot be defined at all, yet alternative 
>> equality definitions might have sense for them. So there are situations 
>> when reasonable defined assignment and equality are not conformant with 
>> your proposition.
>
>Again, I contend that if my rule (requiring consistency of assignment
>and equality testing) does not apply, then those operators are
>inappropriate anyway. You shouldn't use "==" (or whatever your symbol
>is) for comparing two "fuzzy" sets unless you are testing for exact
>equality. Is you are merely testing for similarity, than you should
>write a function called "areSimilar" or some such thing. Otherwise,
>YOU are the one abusing mathematical notation.

For a fuzzy inference engine equality defined as a function having
fuzzy boolean result is perfectly reasonable in both mathematical and
practical sense. It is not an abuse.

>So were back to the original point. Assignment and equality testing
>are very tightly related, and using "=" for assignment is perfectly
>reasonable.

I can only repeat that 'to be related' is not 'to be same'. Your idea
(when applied consequently) is to replace statements with their
postconditions, i.e. instead of saying "what to do" one says "what he
wants to have". It is nothing new, but it was nothing to do with
languages like Ada.

---
Regards,
Dmitry Kazakov
www.dmitry-kazakov.de