Function

1. When the node is activated by an event that refers to the node and there is an instruction STATE, this is first executed. After this execution or when the node is activated because the scanning of the network, the other (non STATE) part of the code may be executed.
2. If the EL is not empty, it is scanned starting from the first message. Each message is examined, the values of the fields are passed to the corresponding field variables and the user code is executed. After this execution, if the message was not extracted, the fields are updated to the values of the field variables (that could have been changed) and the scanning continues.
3. If in the above process a SENDTO instruction is executed, the fields are updated, the message is extracted and sent to the indicated list(s) or successor node(s). The scanning of the EL continues.
4. If a STOPSCAN procedure is executed, the scanning is stopped and the process of the node finishes. However, it may be re-started during the same event if the scan of the network activates again the node. STOPSCAN is used, for instance, if the sending of further messages depends on the changes caused in other nodes by the actually sent message.
5. If a BEGINSCAN procedure is executed, the scanning begins again from the first element. This may be useful if the sending of a message change the sending conditions of the already examined messages. Unwise use of this procedure may cause a loop.
6. Note that the sending of message from a G type node must be explicitly ordered by a SENDTO instruction. To send a message a SENDTO must be executed one and only one time for the examined message.