| 摘要 |
<p>A pattern-matching system, such as of the RETE type, is updated. The updating operation is generalised to operate with correct match results for generalized RETE networks (ones where join nodes may have either predecessor be another join node), and for arbitrary partial update state, and uses stop nodes designating how far update operations have progressed for particular update tokens (designated suspended tokens) at any particular time. The updating operation consists of the follow-ing steps: First, all tokens only partially updated through the network are shadowed, in that the partial result memories associated with the stop nodes are put into the state that exists or existed before the suspended tokens arrive at the stop nodes. Then for each suspended token, it is pushed to resume nodes connected as RHS (or LHS) inputs in a descending order of resume nodes. The descending order is determined among sets of resume nodes where one node is reachable from the other, either in an upwards or downwards direction. Following one token's push to RHS (or LHS) connected resume nodes, that token is unshadowed in the stop node's associated result memory, and that token is then pushed to resume nodes connected as LHS (or RHS) inputs, in an ascending order of resume nodes. Tokens are pushed from alpha top nodes when the stop node is in the alpha portion of the RETE network, to the suspended portion of the successor nodes of the alpha top node.</p> |
