Querying predicate in Prolog and java

Asked Jul 22 '12 at 23:20

Active Feb 14 '13 at 11:28

Viewed 599 times

I want to make a query to use Prolog in java through JPL, I want to call a predicate like this in java:

predicate_test([X,Y,Z]):-
     a_predicate(X),
     another_predicate(Y).

I make the query in java to invoque "predicate_test" like this:

   Query q4=null;
    try{
        q4 = new Query("predicate_test(Percept).");
        System.out.println(q4.query());
    }
    catch(PrologException pl){

        System.out.println(pl.getMessage());
    }

I get this message from the catch block

PrologException: error(existence_error(predicate_test, /(schedule, 1)), context(:(system, /('$c_call_prolog', 0)), _37))

Whats wrong with my approach?

Thanks in advance

edited Jul 22 '12 at 23:49

asked Jul 22 '12 at 23:20

Naty Bizz

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How are you defining the predicate you are trying to use in your query? – Scott Hunter Jul 23 '12 at 00:38
@ScottHunter 'predicate_test' only has the definition shown above, is there anything else I have to add? – Naty Bizz Jul 23 '12 at 01:31
Sorry, I meant how is predicate_test getting asserted into Prolog so that your query can use it? If it isn't in there, it would explain why your query can't find it. – Scott Hunter Jul 23 '12 at 16:17
@ScottHunter thank you, that was the problem, I wasn't calling my prolog file properly – Naty Bizz Jul 23 '12 at 20:41

Querying predicate in Prolog and java

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