/**
* Create an unanalyzed predicate that checks if elements >= i are equal or both sides are null.
*
* <p>The predicate has the form ((lhs[i] is null && rhs[i] is null) || ( lhs[i] is not null &&
* rhs[i] is not null && lhs[i] = rhs[i])) && <createEqualsAux(i + 1)>
*/
private Expr createNullMatchingEqualsAux(
List<Expr> elements, int i, TupleId inputTid, ExprSubstitutionMap bufferedSmap) {
if (i > elements.size() - 1) return new BoolLiteral(true);
// compare elements[i]
Expr lhs = elements.get(i);
Preconditions.checkState(lhs.isBound(inputTid));
Expr rhs = lhs.substitute(bufferedSmap, analyzer_, false);
Expr bothNull =
new CompoundPredicate(
Operator.AND, new IsNullPredicate(lhs, false), new IsNullPredicate(rhs, false));
Expr lhsEqRhsNotNull =
new CompoundPredicate(
Operator.AND,
new CompoundPredicate(
Operator.AND, new IsNullPredicate(lhs, true), new IsNullPredicate(rhs, true)),
new BinaryPredicate(BinaryPredicate.Operator.EQ, lhs, rhs));
Expr remainder = createNullMatchingEqualsAux(elements, i + 1, inputTid, bufferedSmap);
return new CompoundPredicate(
CompoundPredicate.Operator.AND,
new CompoundPredicate(Operator.OR, bothNull, lhsEqRhsNotNull),
remainder);
}
