问题
I would like to create a bunch of "and" and "or" and "not" gates in a directed graph. And then traverse from the inputs to see what they results are.
I assume there is a ready made traversal that would do that but I don't see it. I don't know what the name of such a traversal would be.
Certainly breadth first will not do the job. I need to get ALL the leaves, and go up toward the root. In other words
A = (B & (C & Z))
I need to resolve C @ Z first.
I need to put this type of thing in a graph and to traverse up.
回答1:
You would probably create each of the operations as a node which has N incoming and one outgoing connection. You can of course also have more complex operations encapsuled as a node.
With Neo4j 2.0 I would use Labels for the 3 types of operations.
I assume your leaves would then be boolean values? Actually I think you have many roots and just a single leaf (the result expression)
(input1)-->(:AND {id:1})-->(:OR {id:2})-->(output)
(input2)-->(:AND {id:1})
(input3)------------------>(:OR {id:2})
Then you can use CASE when for decisions on the label type and use the collection predicates (ALL, ANY) for the computation
See: http://docs.neo4j.org/chunked/milestone/cypher-query-lang.html
Predicates: http://docs.neo4j.org/chunked/milestone/query-function.html
Labels: http://docs.neo4j.org/chunked/milestone/query-match.html#match-get-all-nodes-with-a-label
来源：https://stackoverflow.com/questions/16679184/neo4j-logic-gate-simulation-how-to