Logtalk's asserta and ic library

[WitJakuczun]

Hi,
I have a question. Assume I have an object:

Code: Select all

:- object(clp_object).
   :- private(var1/1).
   :- dynamic(var1/1).

   :- private(var2/2).
   :- dynamic(var2/2).

   :- public(add_var1/0).
   :- public(add_var2/0).

   add_var1(Id) :-
        ic:(V :: 0..1),
        asserta(var1([Id, V]))
        .

   add_var2(Id) :-
        ic:(V :: 0..1),
        asserta(var2(Id, V))
        .
:- end_object.   

Now, calling

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clp_object::add_var1(1)

works but

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clp_object::add_var2(1)

is not working (it returns: syntax error: illegal head in rating(3, V{suspend : _1359, ic : ic(integer, 0.0, 1.0, undefined, [], [], [], [])})

What is wrong with 2-ary dynamic predicates?

Best regards,
Wit Jakuczun

[WitJakuczun]

Ok, I have checked this in pure ECLiPSe's prolog code. It
is also not working...
This is offtopic but maybe someone could explain me
why it is not working?

Best regards,
Wit Jakuczun

[Paulo Moura]

Ok, I have checked this in pure ECLiPSe's prolog code. It
is also not working...
This is offtopic but maybe someone could explain me
why it is not working?

Maybe some conflicting operator definitions? Try:

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pmmbp:Desktop pmoura$ eclipse
ECLiPSe Constraint Logic Programming System [kernel]
Kernel and basic libraries copyright Cisco Systems, Inc.
and subject to the Cisco-style Mozilla Public Licence 1.1
(see legal/cmpl.txt or www.eclipse-clp.org/licence)
Source available at www.sourceforge.org/projects/eclipse-clp
GMP library copyright Free Software Foundation, see legal/lgpl.txt
For other libraries see their individual copyright notices
Version 5.10 #103 (i386_macosx), Mon Nov 26 15:44 2007
[eclipse 1]: ic:(V :: 0..1), writeq(V), asserta(v(V)).
WARNING: module 'ic' does not exist, loading library...
ic_kernel.eco loaded traceable 0 bytes in 0.01 seconds
linearize.eco loaded traceable 0 bytes in 0.01 seconds
ordset.eco loaded traceable 0 bytes in 0.00 seconds
ic_constraints.eco loaded traceable 0 bytes in 0.03 seconds
ic.eco     loaded traceable 0 bytes in 0.00 seconds
ic_generic_interface.eco loaded traceable 0 bytes in 0.01 seconds
ic_search.eco loaded traceable 0 bytes in 0.01 seconds
ic.eco     loaded traceable 0 bytes in 0.06 seconds
syntax error: illegal head in v(V{suspend : _1686, ic : ic(integer, 0.0, 1.0, undefined, [], [], [], [])})
_1683{suspend : _1686, ic : ic(integer, 0.0, 1.0, undefined, [], [], [], [])}Abort

I suggest you post the goal above to the ECLiPSE mailing list. Joachim or Kish should be able to clarify this issue.

Cheers,

Paulo

[WitJakuczun]

Thanks. I will post this on ECLiPSe's lists.

Best regards
--
[ Wit Jakuczun <W.Jakuczun [at] wlogsolutions.com> ]
[ WLOG Solutions http://www.wlogsolutions.com ]

[WitJakuczun]

Ok, I have found in SICStus documentation that assert does not work
well with attributed variables (ic variables are attributed).
To do this in sicsctus one could use copy_term. It is well explained
in SICStus documentation.
To do this in ECLiPSe one can use a following trick:

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ic:(V :: 0..1), writeq(V), asserta(v([V])).

I do not know whether it is portable!

Best Regards

[Paulo Moura]

Ok, I have found in SICStus documentation that assert does not work
well with attributed variables (ic variables are attributed).
To do this in sicsctus one could use copy_term. It is well explained
in SICStus documentation.
To do this in ECLiPSe one can use a following trick:

Code: Select all

ic:(V :: 0..1), writeq(V), asserta(v([V])).

I do not know whether it is portable!

That explains something that was puzzling me: why add_var1/1 works while add_var2/ throws an exception. No idea about portability, however; I never used attributed variables (mostly because they are available only in a few Prolog compilers).

Best regards,

Paulo

[WitJakuczun]

I use attributed variables as I use mostly CLP for solving optimisation problems.

I have posted to comp.lang.prolog. Have the wiser speak .

Best regards