@Override
public boolean indexAccessible(final IndexInfo ii) throws QueryException {
final int es = exprs.length;
final boolean[] ng = new boolean[es];
int costs = 0;
for (final FTExpr expr : exprs) {
if (!expr.indexAccessible(ii)) return false;
// use worst costs for estimation, as all index results may need to be scanned
if (costs < ii.costs) costs = ii.costs;
}
ii.costs = costs;
negated = ng;
return true;
}
@Override
public FTExpr compile(final CompileContext cc) throws QueryException {
super.compile(cc);
boolean not = true;
for (final FTExpr expr : exprs) not &= expr instanceof FTNot;
if (not) {
// convert (!A and !B and ...) to !(A or B or ...)
final int es = exprs.length;
for (int e = 0; e < es; ++e) exprs[e] = exprs[e].exprs[0];
return new FTNot(info, new FTOr(info, exprs));
}
return this;
}
@Override
public boolean has(final Flag flag) {
for (final FTExpr e : exprs) if (e.has(flag)) return true;
return false;
}
/**
* Checks if sub expressions of a mild not operator violate the grammar.
*
* @return result of check
*/
boolean usesExclude() {
for (final FTExpr e : exprs) if (e.usesExclude()) return true;
return false;
}