/**
* Checks if the items can be compared. Items are comparable
*
* @param b second item
* @return result of check
*/
public final boolean comparable(final Item b) {
return type == b.type
|| num() && b.num()
|| (unt() || str()) && (b.str() || b.unt())
|| dur() && b.dur()
|| func();
}
/**
* Checks if the specified expression yields a string. Returns a token representation or an
* exception.
*
* @param e expression to be evaluated
* @param ctx query context
* @return item
* @throws QueryException query exception
*/
public final byte[] checkStr(final Expr e, final QueryContext ctx) throws QueryException {
final Item it = checkItem(e, ctx);
if (!it.str() && !it.unt()) Err.type(this, AtomType.STR, it);
return it.atom(input);
}
/**
* Checks if the specified item is a string or an empty sequence. Returns a token representation
* or an exception.
*
* @param it item to be checked
* @return item
* @throws QueryException query exception
*/
public final byte[] checkEStr(final Item it) throws QueryException {
if (it == null) return EMPTY;
if (!it.str() && !it.unt()) Err.type(this, AtomType.STR, it);
return it.atom(input);
}
/**
* Checks if the specified item is a number. Returns a token representation or an exception.
*
* @param it item to be checked
* @return item
* @throws QueryException query exception
*/
public final long checkItr(final Item it) throws QueryException {
if (!it.unt() && !it.type.instance(AtomType.ITR)) Err.type(this, AtomType.ITR, it);
return it.itr(input);
}
/**
* Checks if the specified expression yields a double. Returns the double or throws an exception.
*
* @param e expression to be checked
* @param ctx query context
* @return double
* @throws QueryException query exception
*/
public final double checkDbl(final Expr e, final QueryContext ctx) throws QueryException {
final Item it = checkNoEmpty(e.item(ctx, input), AtomType.DBL);
if (!it.unt() && !it.num()) Err.number(this, it);
return it.dbl(input);
}
/**
* Checks if the specified expression yields a boolean. Returns the boolean or throws an
* exception.
*
* @param e expression to be checked
* @param ctx query context
* @return boolean
* @throws QueryException query exception
*/
public final boolean checkBln(final Expr e, final QueryContext ctx) throws QueryException {
final Item it = checkNoEmpty(e.item(ctx, input), AtomType.BLN);
if (!it.unt() && it.type != AtomType.BLN) Err.type(this, AtomType.BLN, it);
return it.bool(input);
}
@Override
public final int diff(final InputInfo ii, final Item it) throws QueryException {
return !it.unt() ? -it.diff(ii, this) : Token.diff(atom(), it.atom(ii));
}
@Override
public final boolean eq(final InputInfo ii, final Item it) throws QueryException {
return !it.unt() ? it.eq(ii, this) : Token.eq(atom(), it.atom(ii));
}