/**
* Returns the specified expression as normalized database path. Throws an exception if the path
* is invalid.
*
* @param i index of argument
* @param ctx query context
* @return normalized path
* @throws QueryException query exception
*/
private String path(final int i, final QueryContext ctx) throws QueryException {
final String path = string(checkStr(expr[i], ctx));
final String norm = MetaData.normPath(path);
if (norm == null) RESINV.thrw(input, path);
return norm;
}
/**
* Performs the store function.
*
* @param ctx query context
* @return {@code null}
* @throws QueryException query exception
*/
private Item store(final QueryContext ctx) throws QueryException {
checkWrite(ctx);
final Data data = data(0, ctx);
final String path = path(1, ctx);
final IOFile file = data.meta.binary(path);
if (file == null || file.isDir()) RESINV.thrw(input, path);
final Item it = checkItem(expr[2], ctx);
ctx.updates.add(new DBStore(data, token(path), it, input), ctx);
return null;
}