A few questions about Prolog...
phi5...@yahoo.ca
Prolog implementations. Next term, I will be taking a course on logic
programming, and I decided to learn the thing beforehand. I tried a
few Prolog implementations, and would appreciate if the community
could correct my first impressions about the language.
1-- I started with SWI-Prolog, but I ran into an unexpected behavior
of the compiler: I have written a few simple drills for who are
learning French; the programs work, but I get nasty error messages
that spoil the output aesthetic. I posted a simplified version of the
culprit code on this forum, and you can check it if you want. Besides
this, SWI-Prolog seems to use a lot of memory for its many stacks.
Even a small bechmark requires 200 M of stack space. Is it true that
SWI-Prolog uses a lot of memory for stacks? I am not sure whether this
conclusion is correct, because I may be doing something really stupid,
like running the programs with the debug on.
2-- My next trial was GNU-Prolog. Since I need a nice GUI, and I found
three very good GUI implementations for GNU-Prolog, it would be my
first choice, except for its hunger for memory space. In fact, GNU-
Prolog seems to have three stacks, and refuses to run even the
smallest program before getting at least 500 M of memory. For
instance, in order to run tak 100 times, it requires 300M of local
stack, 120M of trail stack, etc. Therefore, the only point that I
could find in favor of GNU-Prolog is a good choice of GUI.
3-- YAP. This implementation is quite interesting. It seems that YAP
is an interpreter, but it is as fast as GNU-Prolog in most benchmarks,
and does not consume as much memory; in fact, YAP goes through all
benchmarks without a single message of memory overflow. Am I right? On
the other hand, I could not find a single GUI ready to go on YAP.
If it had a GUI for Windows, my choice would be YAP. However, I think
that my only option is GNU-Prolog. If I am wrong, let me know.
A.L.
>I have a few questions about Prolog. In fact, the questions are about
>Prolog implementations. Next term, I will be taking a course on logic
>programming, and I decided to learn the thing beforehand. I tried a
>few Prolog implementations, and would appreciate if the community
>could correct my first impressions about the language.
>
>1-- I started with SWI-Prolog, but I ran into an unexpected behavior
>of the compiler: I have written a few simple drills for who are
>learning French; the programs work, but I get nasty error messages
>that spoil the output aesthetic. I posted a simplified version of the
>culprit code on this forum, and you can check it if you want. Besides
>this, SWI-Prolog seems to use a lot of memory for its many stacks.
>Even a small bechmark requires 200 M of stack space. Is it true that
>SWI-Prolog uses a lot of memory for stacks? I am not sure whether this
>conclusion is correct, because I may be doing something really stupid,
>like running the programs with the debug on.
>
I am afraid that behavior of compiler is correct, this what is
unexpected is behavior of your program caused by programming error.
SWI Prolog is no different than other Prologs regarding using memory.
However, wrong programming can cause behavior as you describe, and
this can happen with ANY. See thread anout memory leaks some time ago
on this group.
>2-- My next trial was GNU-Prolog. Since I need a nice GUI, and I found
>three very good GUI implementations for GNU-Prolog, it would be my
>first choice, except for its hunger for memory space. In fact, GNU-
>Prolog seems to have three stacks, and refuses to run even the
>smallest program before getting at least 500 M of memory. For
>instance, in order to run tak 100 times, it requires 300M of local
>stack, 120M of trail stack, etc. Therefore, the only point that I
>could find in favor of GNU-Prolog is a good choice of GUI.
>
There is something wrong with your programs...
>3-- YAP. This implementation is quite interesting. It seems that YAP
>is an interpreter, but it is as fast as GNU-Prolog in most benchmarks,
>and does not consume as much memory; in fact, YAP goes through all
>benchmarks without a single message of memory overflow. Am I right? On
>the other hand, I could not find a single GUI ready to go on YAP.
>
>If it had a GUI for Windows, my choice would be YAP. However, I think
>that my only option is GNU-Prolog. If I am wrong, let me know.
SWI is THE BEST Prolog available among free Prologs. As I recall,
there is also good GUI available for SWI. GNU seems to be a bit
outdated, and is not actively maintained.
A.L.
phi5...@yahoo.ca
Hi, A.L.
Thank you for answering my questions. I will tell you what was my
problem with SWI Prolog GUI. I hope you can tell me what I did wrong.
The program below works perfectly well with all versions of SWI
Prolog, except the last one. In the last version it complains that
prolog_file_type/2 is not declared public. As you can see, I do not
use this predicate. My conclusion is: There is a bug in previous
versions of GNU-Prolog, or the bug is in the current stable version.
The third option is an undocumented change in behavior. By the way,
the program is given in the manual. Therefore, if there is a bug, it
is in the manual. Since the program works with old versions of the
language, a possibility is that SWI-Prolog changed the behavior of a
predicate or another, but the manual is dated.
Since I need a stand along exec file, I saved the program using the
following goal:
?- qsave_program('d:/pl/bin/drill.exe',
[ goal=ask_name,
toplevel=halt,
stand_alone=true]).
Here is the program:
%:- use_module(library(pce)).
ask_name :- nodebug,
new(@nom, dialog('Register')),
send(@nom, append,
new(NameItem, text_item(name))),
send(@nom, append,
new(Eval, text_item(evaluation))),
send(@nom, append,
button(ok, message(@nom, return,
NameItem?selection))),
send(@nom, append,
button(cancel, message(@nom, return, @nil))),
send(@nom, default_button, ok),
test(T,Gab),
%write(T),nl,
send(NameItem,value,T),
get(@nom, confirm, Rval),
%send(NameItem,clear),
checar(Rval,Gab, Eval).
ask_name :-
free(@nom).
test(crayon, pencil).
test(finir, end).
test(livre, book).
A.L.
>
>Hi, A.L.
>Thank you for answering my questions. I will tell you what was my
>problem with SWI Prolog GUI.
Sorry, but:
a. I am not using SWI,
b. I an not using "Prolog GUI". In my opinion (and I am not alone)
Prolog place is on the server, and GUI should be implemented in one of
languages/tools/frameworks that are good for this purpose.
Checj Amzi Porlog "Logic Server", www.amzi.com to see how this can be
done
A.L.
Chip Eastham
> On Sat, 26 Jul 2008 13:55:57 -0700 (PDT), phi50...@yahoo.ca wrote:
>
> >Hi, A.L.
> >Thank you for answering my questions. I will tell you what was my
> >problem with SWI Prolog GUI.
>
> Sorry, but:
>
> a. I am not using SWI,
> b. I an not using "Prolog GUI". In my opinion (and I am not alone)
> Prolog place is on the server, and GUI should be implemented in one of
> languages/tools/frameworks that are good for this purpose.
>
> done
>
> A.L.
Perhaps what the OP means by "GUI" is commonly referred
to as an IDE (integrated development environment).
regards, chip
A.L.
Maybe. But Prolog (actually, almost all Prologs) are not very strong
in this area...
A.L.
Chip Eastham
> On Sun, 27 Jul 2008 20:38:34 -0700 (PDT), Chip Eastham
>
>
>
> <hardm...@gmail.com> wrote:
> >On Jul 26, 10:23 pm, A.L. <alewa...@zanoza.com> wrote:
> >> On Sat, 26 Jul 2008 13:55:57 -0700 (PDT), phi50...@yahoo.ca wrote:
>
> >> >Hi, A.L.
> >> >Thank you for answering my questions. I will tell you what was my
> >> >problem with SWI Prolog GUI.
>
> >> Sorry, but:
>
> >> a. I am not using SWI,
> >> b. I an not using "Prolog GUI". In my opinion (and I am not alone)
> >> Prolog place is on the server, and GUI should be implemented in one of
> >> languages/tools/frameworks that are good for this purpose.
>
> >> done
>
> >> A.L.
>
> >Perhaps what the OP means by "GUI" is commonly referred
> >to as an IDE (integrated development environment).
>
> Maybe. But Prolog (actually, almost all Prologs) are not very strong
> in this area...
>
> A.L.
Hi, A.L.
Since you mentioned Amzi! Prolog (in the context of a
server-based engine), I'll recommend the OP take a look
at the way they leverage the (Java-based) Eclipse IDE
for code editing and debugging:
regards, chip
Jan Wielemaker
> I have a few questions about Prolog. In fact, the questions are about
> Prolog implementations. Next term, I will be taking a course on logic
> programming, and I decided to learn the thing beforehand. I tried a
> few Prolog implementations, and would appreciate if the community
> could correct my first impressions about the language.
>
> 1-- I started with SWI-Prolog, but I ran into an unexpected behavior
> of the compiler: I have written a few simple drills for who are
> learning French; the programs work, but I get nasty error messages
> that spoil the output aesthetic. I posted a simplified version of the
> culprit code on this forum, and you can check it if you want. Besides
> this, SWI-Prolog seems to use a lot of memory for its many stacks.
> Even a small bechmark requires 200 M of stack space. Is it true that
> SWI-Prolog uses a lot of memory for stacks? I am not sure whether this
> conclusion is correct, because I may be doing something really stupid,
> like running the programs with the debug on.
If you run a program in debug mode is disables most of the space
optimizations. In techy talk: it disables last-call optimization and
pushes dummy choicepoints to allow for retry.
Somehow the prolog_file_type message will be fixed if it can be
reproduced. Sofar, I failed. Did you change the default extension
from .pl to something else?
--- Jan
phi5...@yahoo.ca
No, Jan, I did not change the extension from .pl to something else.
However, I discovered that the problem does not happen if I switch to
version version 5.4.7. I will do the following. I will send you a copy
of the program, and the stand alone file that I generated. I think
that this will help you in removing the message.
Jan Wielemaker
>> Somehow the prolog_file_type message will be fixed if it can be
>> reproduced. Sofar, I failed. Did you change the default extension
>> from .pl to something else?
>>
>> --- Jan
>
> No, Jan, I did not change the extension from .pl to something else.
> However, I discovered that the problem does not happen if I switch to
> version version 5.4.7. I will do the following. I will send you a copy
> of the program, and the stand alone file that I generated. I think
> that this will help you in removing the message.
I see it. Please, *don't* send executable code. It doesn't help and
I'll never run it anyway. I'll try to have a look shortly.
--- Ja