Re: No call for Ada (was Re: Announcing new scripting/prototyping language)

["Alexander E. Kopilovich" <aek@VB1162.spb.edu>]

Dmitry A. Kazakov wrote:

> > The problem is that in software it often isn't easy to differentiate a
> > fraud or liable negligence from a reasonable risk, to which the user was
> > knowingly agreed. Almost all computer professionals will agree that given
> > the current state-of-art, there is a risk-cost tradeoff for common
> > software products.
>
> I disagree. 90% of software impose no risk in development. Risk exists, but
> it is related to management, marketing etc.

If you have complete and unambiguous requirements before software development
phase than yes, this development may be error-free. But this means only that
you shifted all the risk to the requirements. If your analysts are much
stronger than your programmers then that may be good tactics. But if not...
you will possibly get a sound failure without any prior warnings/symptoms.

> Anyway, why the customers have to care this risk?

Ask that on a meeting of Customer Party. As for me, the customers do not have
to deal with that risk - they aren't required by law to buy any software (so
far), I think - they may ignore it altogether... and if they still need some
software then they are free (again, so far) to create it by themselves.

Why I have to care about a car incident that can hurt me on the road?
Well, I don't have to, I can choose not to leave my home.

> > And with the risk of eventual software error being
> > pushed too down the cost will skyrocket. So users have a good reason to
> > agree with some risks - because they need (or want) the functionality,
> > provided by the product, but only for a certain price, and not higher.
> > This is a user's choice - either to take a proposed risk, or not to buy
> > the product.
>
> There is no such choice. You know it very well. This is why there are
> regulations, to prevent you from buying rotten food in supermarkets.

We have common understanding of what it means for a food to be rotten - for
many centures. What comes relatively recently - it is just means (methods,
devices) for quick and precise recognition of this state, while its general
definition was commonly agreed long ago.

For software we have no such, commonly agreed definition - partly because we
dealt with software for decades and not for centures. Perhaps it will not
take several centures this time, but the experience, which we have accumulated
so far is not enough.

> As I said before, you need not to look into the code. You have to look at
> the procedure. Compare it with food regulations. Most of them tell that the
> flesh shall be kept under some definite temperature, no longer than ...

With a food, a product is just a copy. So the procedures can cover almost all.
And with software we also have no problems with copying - any vendor or shop
with replace you non-readable CD with good one, without any arguments.

But new software product isn't a copy, you know, and there can't be exact and
complete procedures for its development.

> > Being accesible and usable for large number of diverse people is one of
> > the most essensial qualities for some kinds of software.
>
> Nonsense. This is not a quality to be paid for. It is MS's business. We
> should pay for a text processor, not for an ability to swallow a market
> segment.

You are wrong here, and particularly in the case of MS Word. It is an
important quality for this kind of text processor to be shared by very many
users. Presence of this quality means (for a user) that documents can be
shared, sent and received (note that this isn't just issue of file format,
because different processors may print the same file format slightly
differently, and this is significant for many documents); visual formats and
styles can be more or less easily shared; and learning is much easier for
beginners because very often there are neighbours who already mastered this
text processor.

> >> >> Again, there are issues essential to the existence of our
> >> >> civilization.
> >> > 
> >> > You are so focusing on our civilization... don't you think that
> >> > civilization is quite a complex thing, and it is not easy to determine
> >> > what is essential for it? But at least you don't refer to the God's
> >> > will, and this is good.
> >> > 
> >> >> Software development becomes one of them. Ada is just an indicator of
> >> >> how things are going on.
> >> > 
> >> > Don't you see that these two your sentences contradict each other?
> >> > Ada essentially defies the general notion of "software", Ada expects
> >> > you to analyze each your problem deeply, with all its specifics, not
> >> > relying upon some general "software" fashions and solutions. It does
> >> > not mean that you should forget all your previous experience and it
> >> > doesn not preclude any general computer science - you can use all that
> >> > if it helps you, but you can't rely upon that, you can't get excuses
> >> > from that.
> >>
> >> Where is any contradiction?
> > 
> > You said that software development - general process for general
> > notion/issue - becomes critically important. Then you said that the things
> > are going very badly in this respect. Then you hinted that the negligence
> > to Ada is a symptom as the latter. But Ada essentially defies general
> > notion of "software", so you logically should perceive the negative
> > attitude towards Ada as a good symptom, that is, a symptom of widened
> > understanding of importance of general notion of "software".
>
> Sorry, but I cannot follow you. How a negative attitude to something (Ada),
> which defines X, could be a symptom of widened understanding of importance
> of that X?

A funny thing happened... Inadvertenly we created a good case - a proof of
that even a clear and unambiguous sentence may be confused if it is not
expected. Look, I wrote "defies" (from "defy"), not "defines"!

I wrote it twice, and this was exactly what I meant, but nevertheless you
either overlooked the absence of "n" in this word or decided that this were
just typos, in both cases. After that you naturally had no chance to follow
the logic of the text. And even after second iteration you appear unable
either to recognize the meaning of that word or to believe that your opponent
could say such a strange thing.

Well, I agree that this was an accident - two perfectly legal sentences with
very different, almost opposite meaning happened to be in dangerous lexical
proximity; and the situation was aggravated by the fact that the language of
dialogue was not native for both speakers involved.

It is too hard to prevent *all* significant errors -;)

> What makes you to think that the current level of error-prevention is so
> high that the next step would cost as much as the space-shuttle program? It
> is just guessing, a far from reality one.

Experience... not just my own experience, but experience of 20th century.
When you are trying to increase the level of error-prevention in large scale
then you have to worry very much about not increasing the level of
progress-prevention and the level of diversity-prevention. In 20th century
we have several examples - some very famous, some less known, but nevertheless
quite substantial, where too strong attitude towards error-prevention (without
worrying about side-effects) was a major contributing factor for sound
catastrophes. That is, the achieved good level of error-prevention made the
final catastrophes much more sound.

In many cases, suppressing a natural stream of errors with some general,
domain-independent technique, is similar to switching off sensors that show
unpleasant data.

> With the
> current way of thinking: let's do something and see if it works, where we
> will come?

To the Day Of Judgement, of course.



Alexander Kopilovitch                      aek@vib.usr.pu.ru
Saint-Petersburg
Russia