/**
* Returns the set of groundings that can be derived from the rule and the specific input
* assignment.
*
* @param input the input assignment
* @return the possible groundings for the rule
*/
private RuleGrounding getGroundings(Assignment input) {
RuleGrounding groundings = new RuleGrounding();
for (RuleCase c : cases) {
groundings.add(c.getGroundings(input));
}
return groundings;
}
/**
* Returns the groundings associated with the rule case, given the input assignment
*
* @param input the input assignment
* @return the resulting groundings
*/
public RuleGrounding getGroundings(Assignment input) {
RuleGrounding groundings = new RuleGrounding();
groundings.add(condition.getGroundings(input));
if (ruleType == RuleType.UTIL) {
boolean actionVars = input.containsVars(output.getOutputVariables());
for (Effect e : getEffects()) {
if (actionVars) {
Condition co = e.convertToCondition();
RuleGrounding effectGrounding = co.getGroundings(input);
groundings.add(effectGrounding);
} else {
Set<String> slots = e.getValueSlots();
slots.removeAll(input.getVariables());
groundings.add(Assignment.createOneValue(slots, ""));
}
}
}
return groundings;
}
/**
* Returns the first rule output whose condition matches the input assignment provided as
* argument. The output contains the grounded list of effects associated with the satisfied
* condition.
*
* @param input the input assignment
* @return the matched rule output.
*/
public RuleOutput getOutput(Assignment input) {
RuleOutput output = new RuleOutput(ruleType);
RuleGrounding groundings = getGroundings(input);
for (Assignment g : groundings.getAlternatives()) {
Assignment full = !(g.isEmpty()) ? new Assignment(input, g) : input;
RuleOutput match =
cases
.stream()
.filter(c -> c.condition.isSatisfiedBy(full))
.map(c -> c.output)
.findFirst()
.orElse(new RuleOutput(ruleType));
match = match.ground(full);
output.addOutput(match);
}
return output;
}