The script in a processor definition operates with strongly typed data: the functions and operators accept only declared types of data. The type is assigned to all input fields defined by the USING command as well as to the variables created while parsing or using the casting functions.
Whatever type has a field that is a part of the processor output, the system makes its best effort to convert it to a type expected by the event. The same applies to the input fields defined by the USING command. For example, a STRING attribute with the value 123 can be easily converted to the INTEGER type, but not to the BOOLEAN type.
Data types supported by the USING command (processor input/output):
Additionally, within the processor script itself, more data types may appear after parsing: