Constructing Confluent Context-sensitive Graph Grammars from Non-confluent Productions for Parsing Efficiency
نویسندگان
چکیده
The efficient parsing algorithms are usually confined to confluent graph grammars in context-sensitive formalisms, whereas the confluence condition is not frequently met by graph grammars in practical applications. This paper, based on the Reserved Graph Grammar (RGG) formalism, proposes an extended formalism XRGG which allows imposing constraints characterizing application situations on graph productions. The constraints can make the redexes of the XRGG productions’ right graphs mutually exclusive so as to ensure the confluence of the corresponding graph grammar. Then an algorithm is developed to construct a confluent XRGG graph grammar from an RGG grammar with non-confluent productions for tackling identical graph languages. This method can be easily generalized to other context-sensitive graph grammar formalisms, thus making the efficient parsing algorithm of the RGG that depends on confluent graph grammars more widely applicable.
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