/**
* Ensures that none of the specified expressions performs an update. Otherwise, throws an
* exception.
*
* @param exprs expressions (may be {@code null}, and may contain {@code null} references)
* @throws QueryException query exception
*/
protected final void checkNoneUp(final Expr... exprs) throws QueryException {
if (exprs == null) return;
checkAllUp(exprs);
for (final Expr expr : exprs) {
if (expr != null && expr.has(Flag.UPD)) throw UPNOT_X.get(info, description());
}
}
@Override
public String toString() {
final TokenBuilder tb = new TokenBuilder("map { ");
boolean key = true;
for (final Expr e : expr) {
tb.add(key ? tb.size() > 6 ? ", " : "" : ":=").add(e.toString());
key ^= true;
}
return tb.add(" }").toString();
}
/**
* Ensures that all specified expressions are vacuous or either updating or non-updating.
* Otherwise, throws an exception.
*
* @param exprs expressions to be checked
* @throws QueryException query exception
*/
void checkAllUp(final Expr... exprs) throws QueryException {
// updating state: 0 = initial state, 1 = updating, -1 = non-updating
int s = 0;
for (final Expr expr : exprs) {
expr.checkUp();
if (expr.isVacuous()) continue;
final boolean u = expr.has(Flag.UPD);
if (u && s == -1 || !u && s == 1) throw UPALL.get(info, description());
s = u ? 1 : -1;
}
}
/**
* Checks if the specified expression yields an element. Returns the element or throws an
* exception.
*
* @param ex expression to be evaluated
* @param qc query context
* @return binary item
* @throws QueryException query exception
*/
protected final ANode toElem(final Expr ex, final QueryContext qc) throws QueryException {
return (ANode) checkType(ex.item(qc, info), NodeType.ELM);
}
/**
* Checks if the evaluated expression yields a non-empty item. Returns the atomized item or throws
* an exception.
*
* @param ex expression to be evaluated
* @param qc query context
* @return atomized item
* @throws QueryException query exception
*/
protected final Item toAtomItem(final Expr ex, final QueryContext qc) throws QueryException {
return checkNoEmpty(ex.atomItem(qc, info));
}
/**
* Checks if the specified expression yields a non-empty item. Returns the item or throws an
* exception.
*
* @param ex expression to be evaluated
* @param qc query context
* @param type expected type
* @return item
* @throws QueryException query exception
*/
private Item toItem(final Expr ex, final QueryContext qc, final Type type) throws QueryException {
return checkNoEmpty(ex.item(qc, info), type);
}
/**
* Checks if the specified expression yields a node or {@code null}. Returns the node, {@code
* null}, or throws an exception.
*
* @param ex expression to be evaluated
* @param qc query context
* @return node or {@code null}
* @throws QueryException query exception
*/
protected final ANode toEmptyNode(final Expr ex, final QueryContext qc) throws QueryException {
final Item it = ex.item(qc, info);
return it == null ? null : toNode(it);
}
/**
* Checks if the specified expression yields a node. Returns the boolean or throws an exception.
*
* @param ex expression to be evaluated
* @param qc query context
* @return node
* @throws QueryException query exception
*/
protected final ANode toNode(final Expr ex, final QueryContext qc) throws QueryException {
return toNode(checkNoEmpty(ex.item(qc, info), NodeType.NOD));
}
/**
* Returns a boolean equivalent for the specified expression. If the specified expression yields a
* boolean value anyway, it will be returned as is. Otherwise, it will be wrapped into a boolean
* function.
*
* @param ex expression to be rewritten
* @param info input info
* @param sc static context
* @return expression
*/
protected static Expr compBln(final Expr ex, final InputInfo info, final StaticContext sc) {
return ex.seqType().eq(SeqType.BLN) ? ex : Function.BOOLEAN.get(sc, info, ex);
}
/**
* Checks if the specified expression yields a QName. Returns the item or throws an exception.
*
* @param ex expression to be evaluated
* @param qc query context
* @param empty allow empty result
* @return QNm item
* @throws QueryException query exception
*/
protected final QNm toQNm(final Expr ex, final QueryContext qc, final boolean empty)
throws QueryException {
return toQNm(ex.atomItem(qc, info), empty);
}
/**
* Checks if the specified expression yields a double. Returns the double or throws an exception.
*
* @param ex expression to be evaluated
* @param qc query context
* @return double
* @throws QueryException query exception
*/
protected final double toDouble(final Expr ex, final QueryContext qc) throws QueryException {
return toDouble(ex.atomItem(qc, info));
}
/**
* Checks if the specified expression yields a string or an empty sequence. Returns a value as
* token or throws an exception.
*
* @param ex expression to be evaluated
* @param qc query context
* @return token (empty string if result is an empty sequence)
* @throws QueryException query exception
*/
protected final byte[] toEmptyToken(final Expr ex, final QueryContext qc) throws QueryException {
final Item it = ex.atomItem(qc, info);
return it == null ? EMPTY : toToken(it);
}
/**
* Checks if the specified expression yields a string. Returns a value as token or throws an
* exception.
*
* @param ex expression to be evaluated
* @param qc query context
* @return token
* @throws QueryException query exception
*/
protected final byte[] toToken(final Expr ex, final QueryContext qc) throws QueryException {
final Item it = ex.atomItem(qc, info);
if (it == null) throw EMPTYFOUND_X.get(info, AtomType.STR);
return toToken(it);
}
/**
* Ensures that the specified expression performs no updates. Otherwise, throws an exception.
*
* @param expr expression (may be {@code null})
* @throws QueryException query exception
*/
protected void checkNoUp(final Expr expr) throws QueryException {
if (expr == null) return;
expr.checkUp();
if (expr.has(Flag.UPD)) throw UPNOT_X.get(info, description());
}
/**
* Checks if the specified expression yields a binary item. Returns the binary item or throws an
* exception.
*
* @param ex expression to be evaluated
* @param qc query context
* @return binary item
* @throws QueryException query exception
*/
protected final Bin toBin(final Expr ex, final QueryContext qc) throws QueryException {
return toBin(ex.atomItem(qc, info));
}
/**
* Checks if the specified expression yields a string or binary item.
*
* @param ex expression to be evaluated
* @param qc query context
* @return byte array
* @throws QueryException query exception
*/
protected final byte[] toBytes(final Expr ex, final QueryContext qc) throws QueryException {
return toBytes(ex.atomItem(qc, info));
}
/**
* Checks if the specified expression yields a number or {@code null}. Returns the number, {@code
* null}, or throws an exception.
*
* @param ex expression to be evaluated
* @param qc query context
* @return double
* @throws QueryException query exception
*/
protected final ANum toNumber(final Expr ex, final QueryContext qc) throws QueryException {
final Item it = ex.atomItem(qc, info);
return it == null ? null : toNumber(it);
}
/**
* Checks if the specified expression yields an item of the specified atomic type. Returns the
* item or throws an exception.
*
* @param ex expression to be evaluated
* @param qc query context
* @param type type to be checked
* @return item
* @throws QueryException query exception
*/
protected Item checkAtomic(final Expr ex, final QueryContext qc, final Type type)
throws QueryException {
return checkType(ex.atomItem(qc, info), type);
}
/**
* Checks if the specified expression yields a float. Returns the float or throws an exception.
*
* @param ex expression to be evaluated
* @param qc query context
* @return float
* @throws QueryException query exception
*/
protected final float toFloat(final Expr ex, final QueryContext qc) throws QueryException {
final Item it = ex.atomItem(qc, info);
if (checkNoEmpty(it, AtomType.FLT).type.isNumberOrUntyped()) return it.flt(info);
throw numberError(this, it);
}
