Why Prolog is cool

Syth

Most people haven't heard of Prolog, it's completly unlike standard programming languages that most people would know. Most languages (C,C++,Java etc etc) are based on telling the computer exactly what to do.
Prolog is totally different. Instead you tell the computer what things are. You define logical relations. It's hard to explain, the best way is to try it yourself. You can't write 'normal' programmes in it, it's used a lot in Artifical Inteligence stuff. But you can do some pretty funky stuff.

One great thing about Prolog is that it totally changes the way you think. When you learn a programming language, you learn to think in a certain way. Prolog will get you thinking totally differently, because it works totally differently.

It's hard to explain this. If you're interested in programming and logical stuff, then I advise getting a Prolog programme and writing your own code and messing around with it. It's very easy to learn, once you get your head around it.

hussey

Best Joke I've heard all day

Typedef

to define prolog... we must first define prolog

Syth

It's not a joke. I'm being serious. If you haven't tried Prolog then you can't complain. If you have then why is it a joke? I think it's very cool.

hussey

completly unlike standard programming languages
Correct .. because it's crap

Instead you tell the computer what things are
You still tell it what to do though

You can't write 'normal' programmes in it
Exactly

One great thing about Prolog is that it totally changes the way you think
Yes Your right .. I used to think there is a spoon, but after Prolog I now think .. There is no spoon

Reasons why I dont like prolog :
Things that look correct won't run.
The odvious way is usually in-efficient

and example would be this
f( N, F ) :-
N1 is N - 1,
f( N1, F1 ),
F is N * F1.

now it would be alot easier to write this :
F(N) = N * F(N-1)

If you haven't tried Prolog then you can't complain
I can and so could the 130 ppl that used it with me

I think it's very cool.
Logic and Maths are not kewl .. Full Stop.

gerald

PROLOG solves very specific kind of problems. If you like the enlightenment PROLOG gave you, you might want to check Common LISP, which is suitable for both AI and other jobs.

There are free implementation such as clisp (windows, unix), cmucl(unix)... or commercial demo (lispworks, allegro cl)... to play with.

Tom Dunne

Originally posted by Syth
It's not a joke. I'm being serious. If you haven't tried Prolog then you can't complain. If you have then why is it a joke? I think it's very cool.

I think there are controlled substances being abused here.

I have tried Prolog and I utterly detested it. Partly due to the incompetent manner in which is was taught, partly due to it's limited scope within the field of Artificial Intelligence.

I am doing a college project at the moment and part of it utilises AI techniques. I am doing it all in Java. I am staying as far away from Prolog as possible.

gerald

completly unlike standard programming languages
Correct .. because it's crap

Well, my experience of PROLOG is limited to what I read about it but AFAIK, PROLOG represents a different way of looking at the programming process. It is worth knowing for that reason if you have some time to spare.

pickarooney

Prolog is a hippy's language. That said, I kind of like it.

hussey

EDIT .. as I misquoted someone

gerald

Well, my experience of PROLOG is limited to what I read about it but AFAIK

so your saying you have no experience with it .. but you tell us it's a great language??[

Can you please quote where I wrote it was a great language? I would appreciate that you do not misquote me in the future.

I did know it .. Thankfully I forgot it

I do not think that anybody who made the claim to know PROLOG was ever disappointed by it.
Now, it has become a common trend to claim you know a language after secretly reading "Learn X in 24 hours" or "Learn Y in 20 days". Studies have shown that to achieve expertise in any domain take 10 years. I concede that you do not need to become an expert in a language to judge it, but I would expect you to have written substantial programs to be able to judge the true value of Prolog.

I do not know if you have ever written a substantial program in PROLOG, but I am pretty sure I do not want to hear about it after reading your unargumented claims.

Typedef

Code Monkey say : "To iterate is human, to recurse divine".

hussey

Sorry Gerald .. got you mixed up with other newbie poster

appoligies

Sev

So delightfully welcoming and receiving people are on this forum.

bonkey

Originally posted by hussey
Logic and Maths are not kewl .. Full Stop.

Why you working in IT then

Absolutely every aspect of design and coding is based on logic and maths, as are most areas of network design. I guess maybe adminning can survive without logic - at least judging by most admins I've met


Seriously though....

Prolog is an interesting language, which is utterly the wrong tool for almost every application.

When it is used for what it was designed for, its pretty neat.

Unfortunately, most people who learn it in Uni don't know the theory behind enough of what it was designed for to be able to do anything with it, other than the stuff it doesnt do well. I dont know why they teach it really, because you'd be much better off learning it if and when it was ever going to be useful to you. At that stage, you might have a need which would make it non-crap

jc

Syth

Prolog isn't great for writing programmes, but the great thing about it is that you see the world in a whole new light after trying to use it. That's why it's cool. You can see the world in a new way, you approach problems in a new, logical way after you understand how prolog works.

Another advantage is that you don't have to define inverses of functions which I think is pretty cool.

hussey your example of
f( N, F ) :-
N1 is N - 1,
f( N1, F1 ),
F is N * F1.


would allow you to find the Fibonnaci number, but you don't have to write a new method to find the inverse, you use the same method. That's cool.

Logic and Maths are not kewl .. Full Stop.:mad: :mad: That's not true Maths rocks!!:D

DeadBankClerk

words(File, Words) :- see(File), file2list(List), seen, list2words(Words,List,_).

file2list(List) :- get0(Char), file2list(Char,List).
file2list(-1,[]).
file2list(Char, [Char|Rest]) :- file2list(Rest).

letter(Char) --> [Char], {lowercase(Char)}.
letter(Char) --> [Char], {uppercase(Char)}.
uppercase(Char)   :- Char >= "A", Char =< "Z".
lowercase(Char)   :- Char >= "a", Char =< "z".
whitespace(Char)  :- member(Char, " \t\n\r").
punctuation(Char) :- member(Char, "!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~").

word(Word) --> letter(Char), rest_of_word(Rest), {name(Word, [Char|Rest])}.
rest_of_word([Char|Rest]) --> letter(Char), rest_of_word(Rest).
rest_of_word([]) --> [].

list2words(WordList)    --> [Char], {whitespace(Char)}, list2words(WordList).  % Chomp the whitespace
list2words(WordList)    --> [Char], {punctuation(Char)}, list2words(WordList). % Ignore punctuation
list2words([Word|Tail]) --> word(Word), list2words(Tail).
list2words([]) --> [].

oh fear my win.

Trojan

• How many Prolog programmers does it take to screw in a light bulb?
• False!

Syth

DeadBankCleark what are you trying to do with that code... A disadvantage of Prolog is that it requires explaination...

hussey

I think a Fibonacci in prolog would be

fibonacci(0, R) :-
	R is 0.
fibonacci(1, R) :-
	R is 1.
fibonacci(I, R) :-
	I1 is (I - 1),
	I2 is (I - 2),
	fibonacci(I1, R1),
	fibonacci(I2, R2),
	R is (R1 + R2).

My code was N!

as in Nx(N-1)x(N-2) ..... x 1

etc

and what I meant by Logic + Maths is predicate Calculus

I think prolog might make ya look at languages is a different way .. but not life!!

Have ya ever tried ML?? .. I really liked that ..

Syth

ML? What's ML?

Silent Bob

Originally posted by Syth
DeadBankCleark what are you trying to do with that code... A disadvantage of Prolog is that it requires explaination...

It opens a file, reads all the characters from the file and converts them into a list of atoms where each atom corresponds to a word from the file, words are separated by any of the characters listed in the whitespace/punctuation predicates

decob

Originally posted by Syth
ML? What's ML?

Another functional programming language. I found it easier to use and learn than prolog. Used HASKELL last year, was a bitch at times but that was more to do with what we were doing. but otherwise it was grand

Talliesin

Prolog appears to have advantages for applications like Baysian filters, inference engines etc. I am making this judgement purely on the basis that I've seen good applications of that nature that I've been reliably informed were written in Prolog.

Trebor

i have studined prolog, it was difficult to get my head round it but i liked it but did not see many uses for it in everyday use, not that i am saying that there isn't any, just that not in my day to day use of programming but it could be very pwerful when used correctly

issch

I once wrote a Prolog emulation script in Python.
I messed with it for about half an hour, got bored and forgot how to use it... I may still have it somewhere but probably not.

I thought Prolog was interesting, but little more, it's an entirely different approach to programming, but I find it's quicker (and also easier) to just use C++.

spod

Using something like tuProlog (http://www.lia.deis.unibo.it/Research/2P/) from within java can prove very useful if you're doing something which could benefit from deductive stuff by using it as an embedded prolog parser from within your applications.

oneweb

It's all logical really. But I never said obvious. Don't like it (what I've eh, done of it)

If anyone really can't get enuff PROLOG, feel free to PM me

Gerry

Perhaps there are some practical applications for prolog. But as far as I know it only actually exists for 2 days before project handup/ exam time in college. Its an awful language. Fair enough, learn it if you will be doing stuff that can only be done in prolog, otherwise stay as far away as possible. People would be better off if colleges spent more time teaching them the very basics of programming better, which might cut down on Tommy 2 scoops posting stuff like "I need a loop which counts up stuff" on this board

Rew

We had to do this in prolog recently

http://www.wit.ie/rlacey/ai/Prolog/PROLOG2003_logic_b.doc

I hate prolog....

Fair f*cks to some of my class who put Java and VB front ends on to it. Prolog has potential for backend decision making, but its definalty no for me....

DeadBankClerk

your projects are given as .doc?

horrible

Rew

Depends, that particular lecturer does...