/**
* Logically ands the provided terms with the terms in the formula, replacing this formula with
* the result
*
* @param other the terms to and with this formula
* @return this object.
*/
public BooleanFormula andWith(BooleanFormula other) {
if (other.isTrue()) {
return this;
}
if (other.isFalse() || isFalse()) {
if (booleanTerms == null) {
booleanTerms = new HashSet<BooleanTerm>();
} else {
booleanTerms.clear();
}
isSimplified = true;
return this;
}
if (isTrue()) {
booleanTerms = new HashSet<BooleanTerm>(other.booleanTerms);
return this;
}
BooleanFormula newTerms = new BooleanFormula();
for (BooleanTerm otherTerm : other) {
for (BooleanTerm term : booleanTerms) {
BooleanTerm newTerm = term.andWith(otherTerm);
if (newTerm != null) {
newTerms.add(newTerm);
}
}
}
booleanTerms = newTerms.booleanTerms;
isSimplified = newTerms.isSimplified;
return this;
}
/**
* Resolves the formula using the boolean values specified in <code>features</code>. If there are
* no more un-resolved variables in the forumula, the resulting formula will be either TRUE or
* FALSE.
*
* @param features the values to assign to variables in the formula
* @return this object
*/
public BooleanFormula resolveWith(Features features) {
if (isTrue() || isFalse()) {
return this;
}
BooleanFormula formula = new BooleanFormula();
for (BooleanTerm term : this) {
BooleanTerm evaluated = term.resolveWith(features);
if (evaluated.isFalse()) {
// term is false. Don't add to result
} else if (evaluated.isTrue()) {
// term is true so formula is true
booleanTerms = null;
isSimplified = true;
return this;
} else {
formula.add(evaluated);
}
}
booleanTerms = formula.booleanTerms;
isSimplified = formula.isSimplified;
return this;
}