This is a compilation of frequently asked question related to SICStus Prolog.
This is a compilation of frequently asked question related to SICStus Prolog.
It is maintained by the SICStus Prolog support team. Any questions about this FAQ should be sent to sicstus-support@sics.se. Questions about SICStus Prolog should be addressed as follows:
http://www.sics.se/sicstus/bugreport/bugreport.html.or to
sicstus-support@sics.se
This FAQ is not intended for questions about the Prolog language in general. There is a specific Prolog FAQ for that, available at
[PM] address verified for 3.8.6
http://www.selwerd.nl/~dirk-jan/prolog/faq/
Prolog is a simple but powerful programming language developed at the University of Marseilles, as a practical tool for programming in logic. From a user's point of view the major attraction of the language is ease of programming. Clear, readable, concise programs can be written quickly with few errors.
SICStus Prolog is owned and maintained by the Swedish Institute of Computer Science. Parts of the system were developed by the project "Industrialization of SICStus Prolog" in collaboration with Ericsson Telecom AB, NobelTech Systems AB, Infologics AB and Televerket.
SICStus Prolog follows the mainstream Prolog tradition in terms of
syntax and built-in predicates. As of release 3.8, SICStus Prolog
provides two execution modes: the iso mode, which is fully
compliant with the International Standard ISO/IEC 13211-1 (PROLOG: Part
1--General Core); and the sicstus mode, which is largely
compatible with, e.g., C-Prolog and Quintus Prolog, supports code
written in earlier versions of SICStus Prolog.
The main source of information about SICStus Prolog is the WWW-site at
http://www.sics.se/sicstus/.
and in particular the User's Manual, Release Notes, and this FAQ list, at
http://www.sics.se/sicstus/docs/.
SICStus runs under most UNIX dialects and under Windows 95/98/NT/2000. Release 3.8 is actively being supported on the following platforms:
library(tcltk) you need a Tcl/Tk installation on
your machine, available from
http://dev.scriptics.com
library(jasper) you need a JNI compatible Java
installation, for example Sun's JDK, available from
http://java.sun.com.
library(bdb) you need a Berkeley DB version 2
(version 2.7.5 or later, version 2.7.7 is what is used for the binary
distributions), available from
http://www.sleepycat.comNote that
library(bdb) does not work with version 3 of
Berkeley DB.
SICStus is a commercial product and licensing information can be found on the WWW-site (http://www.sics.se/sicstus/). Free evaluation licenses are available.
Upon completed license agreement, you will receive a mail containing download instructions including confidential passwords and encryption keys. Be sure to read the Release Notes before installation.
If you are a university student, your department may have acquired the right to sub-license SICStus to its students. If that is the case, your department should provide to you download instructions and license codes for the relevant distributions. Your professor should know.
If you think you've discovered a bug or if you have another problem, first read this FAQ list and the release notes. If these do not address your problem, submit a bug report by filling in the form:
http://www.sics.se/sicstus/bugreport/bugreport.html.
Some of the problems in this sections are UNIX (Windows) specific. These are marked [UNIX] ([Windows]).
MSIEXEC cannot be found.
This happens if the installing user does not have Administrator
rights. Either install as the user Administrator or ensure that
the installing user have these rights during installation. If this is
unclear, please contact your system administrator.
This problem should not happen on Windows 95, 98 or 2000.
gzip says "stdin not in gzip format".
This means that the input piped to gzip has been corrupted in some
way. Consider the command line:
% cat file.tar.gz.crypt | crypt password | gzip -cd > file.tar
There are two common reasons this occurs. Either the password
is incorrect, whereby gzip gets a corrupt .gz file as input. Or, the
original file file.tar.gz.crypt was downloaded incorrectly,
typically in ASCII mode instead of binary mode.
sp.exe is there.
What's wrong?
This error message appears when SICStus has been compiled using a
different version of libc.so than your machine has
installed. The message "no such file or directory" does not refer to
sp.exe but to the particular libc.so version that SICStus
expects.
SICStus is currently available as binary distributions for
libc.so.6, a.k.a. glibc, versions 2.0 and 2.1.
Make sure to download the correct version.
The crypt program is not included in Linux-distributions since
the code in it is not free. A replacement can be downloaded from
ftp://ftp.sics.se/archive/sicstus3/aux/crypt.tar.gz
Download it, unpack it and follow the instructions in README.
These issues are mainly of concern when building SICStus from a source distribution.
configure, but nothing happens. Why?
The configure script maintains a cache-file called
config.cache. This file has to be removed between
configure-runs if you've changed the arguments. Alternatively, you can
specify --cache-file=/dev/null, causing configure to avoid
creating a cache-file entirely.
Make sure that there is no site-wide configuration file
(config.site). If configure finds one, it will print a message
similar to:
loading site script /usr/local/etc/config.site creating cache ./config.cache checking SICStus version... 3.8.5 [...]
In this case, configure has found a config.site in
/usr/local/etc.
The solution is to either remove the file or to set the environment
variable CONFIG_SITE to an empty file of your choice. For
example, assuming csh:
% setenv CONFIG_SITE ./config.site % echo "# empty config.site" > ./config.site
There are three pieces of information that you must not mix up.
The message "Failed to locate bootfile" means that SICStus cannot
find either spds.sav or sprt.sav, depending on whether
you are executing a Development System or a Runtime System. If you
are running a Runtime System, you may want to read the chapter
"Runtime Systems" in the User's Manual. If you want to execute
Runtime Systems on machines which do not have SICStus installed
(a.k.a. target machines), read the sections "Runtime Systems on
Target Machines" and the documentation the SP_PATH variable in
the Release Notes and User's Manual.
If you get this message running a Development System, your installation is probably inconsistent. Reinstall SICStus and try again.
break.
What's wrong?
The manual assumes that ^D is the EOF character. Under Windows,
however, it's ^Z. In most contexts, the term end_of_file
terminated by a full stop (.) can be typed instead of the EOF
character.
A generic limitation of SICStus Prolog is that it cannot use more than 256 Mb of virtual memory on 32-bit architectures. This is an artifact of the tagged pointer scheme that we use. We have plans for replacing the tagging scheme, but it's a long term project.
Under Linux on x86, the limit is 128 Mb due to the fact that Linux
sbrk() returns memory starting at 0x08000000. So with a
better Linux sbrk(), the limit would be 256 Mb there too. An
experimental workaround for Linux is available from
sicstus-support@sics.se.
You need a main file for the module, e.g. main.pl
and several subfiles, e.g. sub1.pl, sub2.pl, ...
Lay out the main file as follows:
:- module(ModuleName, ExportList). ... clauses/directives ... :- ensure_loaded(sub1). .. clauses/directives ... :- ensure_loaded(sub2).
The subfiles can contain any clauses and directives, including
ensure_loaded/1 directives, but not module/2 directives.
There is support for unfolding predicates at compile time:
user:goal_expansion/3. For example, assume that
is_ornode(X) (is_andnode(X)) is true if the
shape (principal functor) of X is or/2 (and/2). If
you consult the following:
:- multifile
user:goal_expansion/3.
:- dynamic
user:goal_expansion/3.
user:goal_expansion(is_ornode(Term), _, Term=or(_,_)).
user:goal_expansion(is_andnode(Term), _, Term=and(_,_)).
plan_tree( [N|_Rest], _GuidanceNodes, _Indent ) :-
is_andnode(N).
plan_tree( [N|_Rest], _GuidanceNodes, _Indent ) :-
is_ornode(N).
then plan_tree/3 becomes transformed to:
plan_tree([A|_], _, _) :- A=and(_,_). plan_tree([A|_], _, _) :- A=or(_,_).
If you are using fcompile/1, make sure that the definition of
user:goal_expansion/3, and anything else that the compiler needs
to know, has been loaded at fcompile time. A common idiom is:
?- ensure_loaded(SetOfFiles), fcompile(SetOfFiles).
Note that fcompile/1 is obsolescent with the introduction of
partial saved states (.po files).
Note also that plan_tree/3 will not be able to determinately select a
matching clause based on A, as predicates are indexed on the
shape of the first argument only, which is a list in both
clauses. Achieving indexing on A is the subject of the next question.
Consider the following clauses, with the above goal expansion:
plan_tree( [N|_Rest], _GuidanceNodes, _Indent ) :-
is_andnode(N).
plan_tree( [N|_Rest], _GuidanceNodes, _Indent ) :-
is_ornode(N).
In SICStus, as in most WAMs, indexing is done on the shape of the first
argument. If all arguments are distinct variables A, B,
C, ..., and the first goal is A = Term, indexing will
be done on the shape of Term.
So to enable indexing on the shape of N, you must transform the clause
e.g. to:
plan_tree( [N|_Rest], _GuidanceNodes, _Indent ) :-
plan_tree_flat( N, _Rest, _GuidanceNodes, _Indent ).
plan_tree_flat(N, _Rest, _GuidanceNodes, _Indent ) :-
is_andnode(N).
plan_tree_flat(N, _Rest, _GuidanceNodes, _Indent ) :-
is_ornode(N).
With the above goal expansion, this code will indeed index on N.
Here's some code that purports to print all the Fibonacci numbers.
The author of the code expected retract/1 to backtrack forever, finding
ever new fibs/2 facts.
print_fibs :-
retractall(fib(_)),
assert(fibs(1,1)),
retract(fibs(F1,F2)),
write(F1), nl,
F3 is F1+F2,
assert(fibs(F2,F3)),
fail.
If you run it:
| ?- print_fibs. 1 no
It doesn't work because of the semantics for calls to dynamic predicates in the presence of asserts and retracts. SICStus Prolog complies with the ISO Prolog standard in this respect. Clause 7.5.4 of the standard reads:
Any change in the database that occurs as the result of executing a goal (for example, when the activator of a subgoal is a call ofassertz/1orretract/1) shall affect only an activation whose execution begins afterwards. The change shall not affect any activation that is currently being executed.
In the above example, the retract/1 goal is unaffected by the
subsequent assert, and only succeeds once.
X=[97|X], name(A,X). loops. Is it a bug?
SICStus Prolog mitigates the problem by its ability to unify, compare
assert, and copy cyclic terms without looping. The
write_term/[2,3] built-in predicate can optionally handle
cyclic terms. Unification with occurs-check is available as a
built-in predicate. Predicates testing (a)cyclicity are available in a
library package. Other predicates usually do not handle cyclic terms well.
Wrap the file into an executable Shell script which simply invokes
SICStus. Informational messages can be filtered out by redirecting
stderr to /dev/null. For example:
#!/bin/sh
exec sicstus 2> /dev/null -f -a "$@" <<EOF
% Tell SICStus to consult the sources.
% The embedded command invokes main(Args)
% where Args is the script's arguments passed as a list of atoms.
[user].
main(Args) :-
format('Hello world!\n\c
Invoked with args = ~q\n', [Args]).
:-
prolog_flag(argv, Args), main(Args).
EOF
The above script can be invoked as follows:
scheutz>./hw.sh a 236U ka=ka Hello world! Invoked with args = [a,'236U','ka=ka']
TODO: write.
NOTE: This section applies to UNIX binary distributions only.
As of 3.8, the Tcl/Tk library module is automatically configured by the
installation script (InstallSICStus), after asking a few simple
questions.
InstallSICStus asks for the "Tcl/Tk installation path",
which path should I specify?
The installation path should be specified such that
installation-path/lib contains the Tcl/Tk libraries
(libtcl<version>.so). This is the same as the value of the
--prefix options specified to Tcl/Tk's configure-script.
Unfortunately, there is no solution to this yet. You need to install
Tcl/Tk in the same directory in order for InstallSICStus to find
them.
The symptoms of this is that Windows complains about not finding
tcl<ver>.dll.
SICStus 3.8.6 is compiled against Tcl/Tk version 8.2. If you want to use
another Tcl/Tk version, you need to recompile library(tcltk). You
can do this by following these steps:
(Please do not embark on this unless you are fairly familiar with command-prompts and compilation procedures).
% cd library/tcltk % cl -Ic:/progra~1/Tcl/include -Ic:/progra~1/sicstu~1/include -c *.cIf you do not have a shell which expands "*.c", you need to replace "*.c" with the name of all C source files in
library/tcltk.
% cd library % ../bin/splfr tcltk.pl tcltk/*.obj \ c:/progra~1/Tcl/lib/tcl82.lib c:/progra~1/Tcl/lib/tk82.libAgain, you might need to spell out "*.obj". Also, don't forget to adjust the actual paths to your needs.
The following sample session shows how it may look:
% cl -Ic:/progra~1/Tcl/include -Ic:/progra~1/sicstu~1/include -c *.c
Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 11.00.7022 for 80x86
Copyright (C) Microsoft Corp 1984-1997. All rights reserved.
tcl.c
tk.c
tkappini.c
tkterm.c
tkterm.c(231) : warning C4113: 'void (__cdecl *)(void)' differs in parameter lists from 'v
oid (__cdecl *)(void )'
util.c
Generating Code...
% ../bin/splfr tcltk.pl tcltk/*.obj \
c:/progra~1/Tcl/lib/tcl82.lib c:/progra~1/Tcl/lib/tk82.lib
SICStus 3.8.5 (Windows_NT-4-586): Fri Jan 08 09:44:23 1999
Licensed to SICS
yes
{C:\TEMP\tcltkglu.c generated, 40 msec}
yes
tcltkglu.c
Creating library C:\TEMP\junk.lib and object C:\TEMP\junk.exp
% sicstus
SICStus 3.8.5 (x86-win32-nt-4): Fri Jan 08 09:44:23 1999
Licensed to SICS
| ?- use_module(library(tcltk)).
{loading c:/program files/sicstus prolog/library/tcltk.po...}
{loaded c:/program files/sicstus prolog/library/tcltk.po in module tcltk, 90 msec 27664 bytes}
yes
NOTE: This section is only relevant when compiling source distributions with support for Tcl/Tk.
Most UNIX machines today have Tcl/Tk preinstalled. This reduces the risk of installation difficulties since the linker and the runtime linker usually finds Tcl/Tk in its default paths. Most other installation and/or configuration problems related to Tcl/Tk are caused by improper installation or installation in a path where the linker and runtime linker cannot find Tcl/Tk.
Tcl/Tk is configured for installation similar to SICStus; by the use
of a configure script generated by GNU Autoconf. The
installation directory is specified by the --prefix option. The
value of this option is referred to as the installation-dir
below.
Tcl_Init
and/or Tk_Init. What should I do?
The following message from configure indicates that it could
not link a test program with the Tcl/Tk libraries.
... checking for Tcl_Init in -ltcl8.3... no checking for Tk_Init in -ltk8.3... no ...
The common cause of this is that the compiler cannot find
-ltcl8.3 and/or -ltk8.3 (or whichever version it tries
to find), usually because Tcl/Tk has been installed in a non-standard
directory (i.e. different from /usr/lib, /usr/local/lib, etc.).
If you've installed Tcl/Tk in installation-dir, specify the
following to configure:
% ./configure --with-tcltk=installation-dir more options
The problem can occur even if the Tcl/Tk shared libraries can be
found, but the link-phase failed due to other reasons. If this occurs,
it is often useful to look in config.log, where output from
compilation stages etc. is logged.
You can use:
% ./configure --with-tcl=tclinstallpath --with-tk=tkinstallpath
You need to specify --enable-shared when configuring
Tcl/Tk. This is not enabled by default.
This means that Tcl/Tk can't find its libraries of tcl-code needed for
operation. This occurs when Tcl/Tk has been built but not properly
installed. You have the option of stating the location of the
libraries by means of the environment variables TCL_LIBRARY and
TK_LIBRARY. See also the Tcl/Tk documentation.
Another reason for this could be if you are not using SICStus 3.8.1 or later. The original SICStus 3.8 did not initialize Tcl/Tk correctly.
This message can appear in Tcl code which tries to access Prolog variables. Example:
tk_test :-
tk_new([],Interp),
tcl_eval(Interp,
'
global var
set Tree []
set Children []
set GrandChildren []
prolog {get_tree(Tree),
make_children(Tree, Children),
make_grandChildren(Tree, Children, GrandChildren)}
puts "$var(Tree) $var(Children) $var(GrandChildren) "
', _),
tk_main_loop,
tcl_delete(Interp).
The problem is that the argument to the prolog function is just a
string that is interpreted by Prolog as a goal. There is no connection
between the Prolog variables Tree, Children and
GrandChildren and the Tcl-variables with the same name. After
returning from prolog, the values which the Prolog variables have been
bound to are assigned to the array variable prolog_variables.
So replacing $var in your example with $prolog_variables, makes it work.
First try to get a simple "Hello world" program to work that does not use Jasper. A large portion of the support questions we get are unrelated to the SICStus Java interface. Once you can compile and run your own Java classes it should be relatively easy to get Jasper to work.
Read the Release Notes and the User's Manual and the section in them related to Jasper.
splfr insists on looking for JDK in C:/jdk1.2.2
Use the --with-jdk option like this:
splfr --with-jdk=D:/jdk1.3 ...
As of SICStus 3.8.6 this should work. Read the release notes for important information about JDK 1.3 and JDK 1.3.1.
Jasper is built as a layer on top of SICStus' C-Prolog interface and hence Jasper needs to be able to call methods declared as native (i.e., C functions). For security reasons, this is prohibited in applets.
This is a serious restriction, and future versions of Jasper will most likely allow connecting to the Prolog engine via sockets.
java ClassUsingJasper. What's wrong?
The answer to this (and related questions) can be found in the Jasper chapter of the Release Notes, section "Getting Started".
SICStus 3.8 supports standard Prolog, adhering to the International
Standard ISO/IEC 13211-1 (PROLOG: Part 1--General Core). At the same
time it also supports programs written in earlier versions of SICStus.
This is achieved by introducing two execution modes iso and
sicstus. Users can change between the modes using the Prolog flag
language. Main issues:
sicstus execution mode is practically identical to 3.7.1, except for
minor changes in error term format.
iso mode is fully compliant with ISO standard, but no strict
conformance mode is provided.
sicstus execution
mode, unless they conflict with existing SICStus predicates or
functions. This expansion of the language carries a remote risk of name
clashes with user code.
spwin.exe) can save a transcript of the
interaction with the Prolog top-level. The command is under the
File menu. You may wish to increase the number of save lines in the Windows Settings (under the Settings
menu).
spwin.exe)?
See Command line editing.