От	Dervish
К	Novik
Дата	25.04.2001 22:30:15
Рубрики	Прочее; Современность; Евреи и Израиль; Политек;

Не согласен о коректности вопроса!

---

День добрый еще раз!

>>2) Как Вы оцениваете Аду в сравнении с более поздними языками - Си++ и Джава?
>
>...Это примерно как если бы я спросил у
>Вас что-то типа "Как Вы оцениваете пистолет ТТ
>Короче говоря, вопрос некорректен. Разные
>сферы применения.

Ну уж нет - вопрос вполне корректен.
Я спрашиваю именно о языке программирования, а не о сфере применения. Почему это на Си++, джаве, бейсике или фортране нельзя писать того же что на аде - и наоборот.
Управляюцие конструкции, средства определения АТД, языковые средства поддержки (выражения) модульной структуры или определенных дисцеплин программирования - это черты, _инвариатнтые_ (или независимые)относительно области применения языка... Правда это офф-топик тут, о нем можно и по почте - epakudin@hotmail.com

C уважением -
Dervish

---

От	Novik
К	Dervish (25.04.2001 22:30:15)
Дата	27.04.2001 11:07:29

Re: Не согласен...

---

Приветствую.

Все нижеследующее - AFAIK и IMHO :)

>Ну уж нет - вопрос вполне корректен.
>Я спрашиваю именно о языке программирования, а не о сфере применения. Почему это на Си++, джаве, бейсике или фортране нельзя писать того же что на аде - и наоборот.

Можно. Затраты разные. У каждого из языков свои преимущества и свои недостатки. В принципе, любой проект можно реализовать на Visual Basic. Вопрос, правда, сколько времени это займет, и как будет работать.

1) C++. Страуструп решил скрестить коня и трепетную лань. Т.е. к полуассемблеру добавить ОО. В результате получилось ни то ни се. Как особую изюминку унаследовал от предка препроцессор. Что дает возможность рисовать такие конструкции, что черт ногу сломит в исходном коде. Язык-ядро (Операции ввода/вывода реализуются библиотеками, нет встроенной поддержки многозадачности и т.п.) Отсутствие модульности (Конструкции с хидерами это таки не модульность).
Вообщем, конструктор "сделай сам".
Как преимущество можно назвать распространенность. Компилятор только ленивый не написал.

2) Java. Основную область применения знаете :) Преимущества - независимось от среды исполнения. Но это теоретически. На практике преимуществ нет (по крайней мере в серьезных проектах) и расспространять код приходится с конкретной VM под которую он заточен. Дохлое дело, короче. Когда вижу оракловый инсталлятор на java рука тянется к маузеру.

3) Ада. Тут Василий лучше расскажет, ибо когда я к ней имел касательство полноценного компилятора еще не существовало. Язык-оболочка. Встроенные механизмы поддержки многозадачности и т.п.
Поддержка модульности. Рабочих компиляторов не знаю. Не распространен.

---

От	И. Кошкин
К	Novik (27.04.2001 11:07:29)
Дата	27.04.2001 14:36:45

Дико извиняюсь, хидер - это хедер, в смысле h? (-)

---

---

От	Novik
К	И. Кошкин (27.04.2001 14:36:45)
Дата	27.04.2001 14:52:35

Re: Да (-)

---

---

От	И. Кошкин
К	Novik (27.04.2001 14:52:35)
Дата	27.04.2001 15:14:44

Ну так и пиши, а то меня чуть кондратий не хватил))).

---

Я вас приветствую! Хррр. Хрррр. Ххуррагх!

А макросами и условной компилляцией дедушка Страуструп и сам не рекомендует пользоваться. Мол от Си осталось, а тут не нужно, ибо затрудняет чтение и ведет к ошибкам)))

С уважением,
И. Кошкин

---

От	Novik
К	И. Кошкин (27.04.2001 15:14:44)
Дата	27.04.2001 16:07:46

Re: Дык, я ж и говорю.

---

Приветствую.

>Я вас приветствую! Хррр. Хрррр. Ххуррагх!

>А макросами и условной компилляцией дедушка Страуструп и сам не рекомендует пользоваться.

Попытка запрячь в одну телегу коня и трепетную лань. Мало ли что не рекомендуется. Возможность-то есть. И от строгой типизации рожки да ножки. Вот и имеем такой геморрой... Обьектный ассемблер.

---

От	Василий Фофанов
К	Novik (27.04.2001 16:07:46)
Дата	27.04.2001 16:30:41

Что советовал жедушка Страуструп

---

________________________________________________________________

On the 1st of January, 1998, Bjarne Stroustrup gave an interview
to the IEEE's 'Computer' magazine.

Naturally, the editors thought he would be giving a retrospective
view of seven years of object-oriented design, using the language
he created.

By the end of the interview, the interviewer got more than he had
bargained for and, subsequently, the editor decided to suppress its
contents, 'for the good of the industry' but, as with many of these
things, there was a leak.

Here is a complete transcript of what was said, unedited, and
unrehearsed, so it isn't as neat as planned interviews.

You will find it interesting...

__________________________________________________________________

Interviewer: Well, it's been a few years since you changed the
world of software design, how does it feel, looking back?

Stroustrup: Actually, I was thinking about those days, just before
you arrived. Do you remember? Everyone was writing 'C'
and, the trouble was, they were pretty damn good at it.
Universities got pretty good at teaching it, too. They were
turning out competent - I stress the word 'competent' -
graduates at a phenomenal rate. That's what caused the
problem.

Interviewer: Problem?

Stroustrup: Yes, problem. Remember when everyone wrote Cobol?

Interviewer: Of course, I did too

Stroustrup: Well, in the beginning, these guys were like demi-gods.
Their salaries were high, and they were treated like royalty.

Interviewer: Those were the days, eh?

Stroustrup: Right. So what happened? IBM got sick of it, and
invested millions in training programmers, till they were a
dime a dozen.

Interviewer: That's why I got out. Salaries dropped within a year,
to the point where being a journalist actually paid better.

Stroustrup: Exactly. Well, the same happened with 'C' programmers.

Interviewer: I see, but what's the point?

Stroustrup: Well, one day, when I was sitting in my office, I
thought of this little scheme, which would redress the
balance a little. I thought 'I wonder what would happen, if
there were a language so complicated, so difficult to learn,
that nobody would ever be able to swamp the market with
programmers? Actually, I got some of the ideas from X10,
you know, X windows. That was such a bitch of a graphics
system, that it only just ran on those Sun 3/60 things.
They had all the ingredients for what I wanted. A really
ridiculously complex syntax, obscure functions, and
pseudo-OO structure. Even now, nobody writes raw X-windows
code. Motif is the only way to go if you want to retain
your sanity.

Interviewer: You're kidding...?

Stroustrup: Not a bit of it. In fact, there was another problem.
Unix was written in 'C', which meant that any 'C' programmer
could very easily become a systems programmer. Remember
what a mainframe systems programmer used to earn?

Interviewer: You bet I do, that's what I used to do.

Stroustrup: OK, so this new language had to divorce itself from
Unix, by hiding all the system calls that bound the two
together so nicely. This would enable guys who only knew
about DOS to earn a decent living too.

Interviewer: I don't believe you said that...

Stroustrup: Well, it's been long enough, now, and I believe most
people have figured out for themselves that C++ is a waste
of time but, I must say, it's taken them a lot longer than I
thought it would.

Interviewer: So how exactly did you do it?

Stroustrup: It was only supposed to be a joke, I never thought
people would take the book seriously. Anyone with half a
brain can see that object-oriented programming is
counter-intuitive, illogical and inefficient.

Interviewer: What?

Stroustrup: And as for 're-useable code' - when did you ever hear
of a company re-using its code?

Interviewer: Well, never, actually, but...

Stroustrup: There you are then. Mind you, a few tried, in the
early days. There was this Oregon company - Mentor
Graphics, I think they were called - really caught a cold
trying to rewrite everything in C++ in about '90 or '91. I
felt sorry for them really, but I thought people would learn
from their mistakes.

Interviewer: Obviously, they didn't?

Stroustrup: Not in the slightest. Trouble is, most companies
hush-up all their major blunders, and explaining a $30
million loss to the shareholders would have been difficult.
Give them their due, though, they made it work in the end.

Interviewer: They did? Well, there you are then, it proves O-O works.

Stroustrup: Well, almost. The executable was so huge, it took
five minutes to load, on an HP workstation, with 128MB of
RAM. Then it ran like treacle. Actually, I thought this
would be a major stumbling-block, and I'd get found out
within a week, but nobody cared. Sun and HP were only too
glad to sell enormously powerful boxes, with huge resources
just to run trivial programs. You know, when we had our
first C++ compiler, at AT&T, I compiled 'Hello World', and
couldn't believe the size of the executable. 2.1MB

Interviewer: What? Well, compilers have come a long way, since then.

Stroustrup: They have? Try it on the latest version of g++ - you
won't get much change out of half a megabyte. Also, there
are several quite recent examples for you, from all over the
world. British Telecom had a major disaster on their hands
but, luckily, managed to scrap the whole thing and start
again. They were luckier than Australian Telecom. Now I
hear that Siemens is building a dinosaur, and getting more
and more worried as the size of the hardware gets bigger, to
accommodate the executables. Isn't multiple inheritance a joy?

Interviewer: Yes, but C++ is basically a sound language.

Stroustrup: You really believe that, don't you? Have you ever sat
down and worked on a C++ project? Here's what happens:
First, I've put in enough pitfalls to make sure that only
the most trivial projects will work first time. Take
operator overloading. At the end of the project, almost
every module has it, usually, because guys feel they really
should do it, as it was in their training course. The same
operator then means something totally different in every
module. Try pulling that lot together, when you have a
hundred or so modules. And as for data hiding. God, I
sometimes can't help laughing when I hear about the problems
companies have making their modules talk to each other. I
think the word 'synergistic' was specially invented to twist
the knife in a project manager's ribs.

Interviewer: I have to say, I'm beginning to be quite appalled at
all this. You say you did it to raise programmers'
salaries? That's obscene.

Stroustrup: Not really. Everyone has a choice. I didn't expect
the thing to get so much out of hand. Anyway, I basically
succeeded. C++ is dying off now, but programmers still get
high salaries - especially those poor devils who have to
maintain all this crap. You do realise, it's impossible to
maintain a large C++ software module if you didn't actually
write it?

Interviewer: How come?

Stroustrup: You are out of touch, aren't you? Remember the typedef?

Interviewer: Yes, of course.

Stroustrup: Remember how long it took to grope through the header
files only to find that 'RoofRaised' was a double precision
number? Well, imagine how long it takes to find all the
implicit typedefs in all the Classes in a major project.

Interviewer: So how do you reckon you've succeeded?

Stroustrup: Remember the length of the average-sized 'C' project?
About 6 months. Not nearly long enough for a guy with a
wife and kids to earn enough to have a decent standard of
living. Take the same project, design it in C++ and what do
you get? I'll tell you. One to two years. Isn't that
great? All that job security, just through one mistake of
judgement. And another thing. The universities haven't
been teaching 'C' for such a long time, there's now a
shortage of decent 'C' programmers. Especially those who
know anything about Unix systems programming. How many guys
would know what to do with 'malloc', when they've used 'new'
all these years - and never bothered to check the return
code. In fact, most C++ programmers throw away their return
codes. Whatever happened to good ol' '-1'? At least you
knew you had an error, without bogging the thing down in all
that 'throw' 'catch' 'try' stuff.

Interviewer: But, surely, inheritance does save a lot of time?

Stroustrup: Does it? Have you ever noticed the difference between
a 'C' project plan, and a C++ project plan? The planning
stage for a C++ project is three times as long. Precisely
to make sure that everything which should be inherited is,
and what shouldn't isn't. Then, they still get it wrong.
Whoever heard of memory leaks in a 'C' program? Now finding
them is a major industry. Most companies give up, and send
the product out, knowing it leaks like a sieve, simply to
avoid the expense of tracking them all down.

Interviewer: There are tools...

Stroustrup: Most of which were written in C++.

Interviewer: If we publish this, you'll probably get lynched, you
do realise that?

Stroustrup: I doubt it. As I said, C++ is way past its peak now,
and no company in its right mind would start a C++ project
without a pilot trial. That should convince them that it's
the road to disaster. If not, they deserve all they get. You
know, I tried to convince Dennis Ritchie to rewrite Unix in C++.

Interviewer: Oh my God. What did he say?

Stroustrup: Well, luckily, he has a good sense of humor. I think
both he and Brian figured out what I was doing, in the early
days, but never let on. He said he'd help me write a C++
version of DOS, if I was interested.

Interviewer: Were you?

Stroustrup: Actually, I did write DOS in C++, I'll give you a demo
when we're through. I have it running on a Sparc 20 in the
computer room. Goes like a rocket on 4 CPU's, and only
takes up 70 megs of disk.

Interviewer: What's it like on a PC?

Stroustrup: Now you're kidding. Haven't you ever seen Windows '95?
I think of that as my biggest success. Nearly blew the game
before I was ready, though.

Interviewer: You know, that idea of a Unix++ has really got me
thinking. Somewhere out there, there's a guy going to try it.

Stroustrup: Not after they read this interview.

Interviewer: I'm sorry, but I don't see us being able to publish
any of this.

Stroustrup: But it's the story of the century. I only want to be
remembered by my fellow programmers, for what I've done for
them. You know how much a C++ guy can get these days?

Interviewer: Last I heard, a really top guy is worth $70 - $80 an
hour.

Stroustrup: See? And I bet he earns it. Keeping track of all the
gotchas I put into C++ is no easy job. And, as I said
before, every C++ programmer feels bound by some mystic
promise to use every damn element of the language on every
project. Actually, that really annoys me sometimes, even
though it serves my original purpose. I almost like the
language after all this time.

Interviewer: You mean you didn't before?

Stroustrup: Hated it. It even looks clumsy, don't you agree? But
when the book royalties started to come in... well, you get
the picture.

Interviewer: Just a minute. What about references? You must
admit, you improved on 'C' pointers.

Stroustrup: Hmm. I've always wondered about that. Originally, I
thought I had. Then, one day I was discussing this with a
guy who'd written C++ from the beginning. He said he could
never remember whether his variables were referenced or
dereferenced, so he always used pointers. He said the
little asterisk always reminded him.

Interviewer: Well, at this point, I usually say 'thank you very
much' but it hardly seems adequate.

Stroustrup: Promise me you'll publish this. My conscience is
getting the better of me these days.

Interviewer: I'll let you know, but I think I know what my editor
will say.

Stroustrup: Who'd believe it anyway? Although, can you send me a
copy of that tape?

Interviewer: I can do that.


С уважением, Василий Фофанов, http://members.dencity.com/fofanov/Tanks

---

От	Guy
К	Василий Фофанов (27.04.2001 16:30:41)
Дата	27.04.2001 17:46:16

Eто нaстояшee интeрвью или шуткa ? (-)

---

---

От	И. Кошкин
К	Василий Фофанов (27.04.2001 16:30:41)
Дата	27.04.2001 17:11:17

Дедушка пытается шокировать)))) (-)

---

---

От	Novik
К	И. Кошкин (27.04.2001 17:11:17)
Дата	27.04.2001 17:18:31

Re: IMHO это вообще мистификация (-)

---

---

От	Василий Фофанов
К	Novik (27.04.2001 11:07:29)
Дата	27.04.2001 13:33:16

Кое-что изменилось конечно :)

---

>3) Ада. Тут Василий лучше расскажет, ибо когда я к ней имел касательство полноценного компилятора еще не существовало.

Профессиональных и впрямь очень немного, штук навскидку 5, но они есть. С другой стороны и плюс-плюсовых профессиональных ИМХО не больше. Разница разве что в том, что непрофессиональных для ады не бывает ;)

Бесплатных существует только один, наш.

> Не распространен.

Ну или правильнее сказать "широко известен в узких кругах". ;)Кроме военных всех стран, им еще например пользуются гражданские авиационщики, или к примеру такая крупнейшая сеть французского кабельного ТВ, как Канал-плюс.

С уважением, Василий Фофанов, http://members.dencity.com/fofanov/Tanks

---