public static void main(String[] args) {
YProlog engine = new YProlog();
engine.consult("append([],L,L).");
engine.consult("append([A|B],L,[A|Tail]) :- append(B,L,Tail).");
// String query = "append(X,[c],[a,n(J),cs])" ;
String query = "asserta(a(1))";
String value = engine.queryToString(query);
if (value != null) log.debug(value.toString());
String[] result = engine.queryToTable(query);
if (result != null)
for (int i = 0; i < result.length; i++) log.debug("Result " + i + ":" + result[i]);
Vector results = engine.queryToTable(query, 0, true);
if (results != null)
for (int i = 0; i < results.size(); i++) {
log.debug("Results " + i);
result = (String[]) results.elementAt(i);
for (int j = 0; j < result.length; j++) log.debug("Result" + j + ": " + result[j]);
}
}
public void unifyTree(Tree tree, String unifiedGoal) throws InferenceEngineException {
String query =
"old("
+ tree.getGoal()
+ ","
+ tree.getLastExpandedGoal()
+ ","
+ tree.getResolvent()
+ ")";
log.debug("Unify new query: " + unifiedGoal + " and old query: " + query);
checkEngine();
// PrologTerm oldQuery = PrologTools.getTerm(query) ;
// PrologTerm newQuery = PrologTools.getTerm(unifiedGoal) ;
log.debug("unification(" + query + "," + unifiedGoal + ",Result)");
String[] result = _engine.queryToTable("unification(" + query + "," + unifiedGoal + ",Result)");
if (result == null) {
log.debug("No answers");
throw new InferenceEngineException("Error unifying " + query + " and " + unifiedGoal);
}
PrologTerm term;
try {
term = PrologTools.getTerm(result[0]);
} catch (ParseException e) {
throw new InferenceEngineException(e);
}
if ((term == null) || (!(term instanceof PrologCompoundTerm)))
throw new InferenceEngineException("Resulting value '" + term + "' is wrong");
else {
log.debug("Term: " + term);
PrologCompoundTerm t = (PrologCompoundTerm) term;
tree.setLastExpandedGoal(null);
tree.setGoal(t.getArg(0).getText());
tree.setResolvent(t.getArg(2).getText());
}
}
public LogicAnswer[] processTree(LogicQuery logicQuery) throws InferenceEngineException {
log.debug("Process logic query: " + logicQuery.getGoal() + " - " + logicQuery.getSubgoals());
checkEngine();
String query =
"tree("
+ logicQuery.getGoal()
+ ","
+ logicQuery.getSubgoals()
+ ","
+
// "[]," +
logicQuery.getRequester()
+ ")";
log.debug("Query: " + query);
Vector results = _engine.queryToTable("processTree(" + query + ",Result)", 0, true);
if (results == null) {
log.debug("No answers");
return null;
}
log.debug("Receiving from engine " + results.size() + " results");
String[] result;
PrologTerm term;
LogicAnswer[] answers = new LogicAnswer[results.size()];
for (int i = 0; i < results.size(); i++) {
log.debug("Results " + i);
result = (String[]) results.elementAt(i);
try {
for (int j = 0; j < result.length; j++) log.debug("Term: " + result[j]);
term = PrologTools.getTerm(result[1]);
} catch (ParseException e) {
throw new InferenceEngineException(e);
}
if ((term == null) || (!(term instanceof PrologCompoundTerm)))
throw new InferenceEngineException("Resulting value '" + term + "' is wrong");
else {
PrologCompoundTerm t = (PrologCompoundTerm) term;
String delegator = t.getArg(5).getText();
if (delegator.equals("nil")) delegator = null;
answers[i] =
new LogicAnswer(
t.getArg(0).getText(),
t.getArg(4).getText(),
t.getArg(1).getText(),
t.getArg(2).getText(),
t.getArg(3).getText(),
delegator);
log.debug("Answer: " + answers[i]);
}
}
return answers;
}