10. A structural matching engine, comprising: a microprocessor coupled to memory, wherein the microprocessor is programmed to perform non-deterministic finite automaton filtering operations through: an active node processor (ANP) which processes a state of an active list to determine possible future states of a non-deterministic finite automaton (NFA), the ANP processing the state according to rules; and an active list processor (ALP) which initiates a lookup for a token value corresponding to the state of the active list, the ALP providing a next state of the active list to the ANP for processing according to the rules upon completion of the processing of the state by the ANP, wherein the possible future states of the NFA are linked by the ALP to form a target list, the target list stacked on top of the active list in a stack structure.
10. A structural matching engine, comprising: a microprocessor coupled to memory, wherein the microprocessor is programmed to perform non-deterministic finite automaton filtering operations through: an active node processor (ANP) which processes a state of an active list to determine possible future states of a non-deterministic finite automaton (NFA), the ANP processing the state according to rules; and an active list processor (ALP) which initiates a lookup for a token value corresponding to the state of the active list, the ALP providing a next state of the active list to the ANP for processing according to the rules upon completion of the processing of the state by the ANP, wherein the possible future states of the NFA are linked by the ALP to form a target list, the target list stacked on top of the active list in a stack structure. 14. The structural matching engine of claim 10 , wherein the ALP maintains a first and second list while the ANP processes the states of the active list, the first list representing elements that match a query and the second list representing elements not matching the query.