@Override
public boolean uses(final Use u) {
for (final Expr p : pred) {
if (u == Use.POS && p.type().mayBeNum() || p.uses(u)) return true;
}
return false;
}
/**
* Tests if the specified expressions are updating or vacuous.
*
* @param ctx query context
* @param expr expression array
* @throws QueryException query exception
*/
public void checkUp(final QueryContext ctx, final Expr... expr) throws QueryException {
if (!ctx.updating) return;
int s = 0;
for (final Expr e : expr) {
if (e.vacuous()) continue;
final boolean u = e.uses(Use.UPD);
if (u && s == 2 || !u && s == 1) UPNOT.thrw(input, desc());
s = u ? 1 : 2;
}
}
@Override
public final boolean removable(final Var var) {
for (final Expr step : steps) if (step.uses(var)) return false;
return root == null || root.removable(var);
}
@Override
public boolean removable(final Var var) {
for (final Expr p : preds) if (p.uses(var)) return false;
return true;
}
@Override
public boolean uses(final Use u) {
if (u == Use.VAR) return true;
for (final TypeCase c : cases) if (c.uses(u)) return true;
return ts.uses(u);
}
/**
* Checks if the specified expressions is no updating expression.
*
* @param e expression
* @param ctx query context
* @return the specified expression
* @throws QueryException query exception
*/
public final Expr checkUp(final Expr e, final QueryContext ctx) throws QueryException {
if (e != null && ctx.updating && e.uses(Use.UPD)) UPNOT.thrw(input, desc());
return e;
}