/**
* Initialize the choice point state.
*
* @param interpreter the parent interpreter whose state is to be preserved here, its arg stack
* defines the parameters for the target goal
*/
@Override
public void init(LPInterpreter interpreter) {
super.init(interpreter);
context = interpreter.getContext();
generator = interpreter.getEngine().generatorFor(goal);
generator.addConsumer(this);
resultIndex = 0;
}
/** Restore the state of an interpreter from this frame */
public void restoreState(LPInterpreter interp) {
interp.unwindTrail(0);
for (int i = 0; i < trailLength; i++) {
interp.bind(trailVars[i], trailValues[i]);
}
if (pVars != null) {
System.arraycopy(pVars, 0, envFrame.pVars, 0, pVars.length);
}
}
/**
* Constructor. Initialize the triple match to preserve the current context of the given
* LPInterpreter and search for the match defined by the current argument registers
*
* @param intepreter the interpreter instance whose env, trail and arg values are to be preserved
*/
public TopLevelTripleMatchFrame(LPInterpreter interpreter, TriplePattern goal) {
init(interpreter);
this.matchIterator = interpreter.getEngine().getInfGraph().findDataMatches(goal);
this.goal = goal;
}