Using shared-packed forests in a GB parser

By utilizing structure sharing among its parse trees, a GB parser can increase its efficiency dramatically. Using a GB parser which has as its phrase structure recovery component an implementation of Tomita´s natural language algorithm (M. Tomita, 1986), we investigate how a GB parser can preserve the structure sharing output by Tomita´s algorithm. We give some details of the structure-sharing parser currently under construction. Our approach to preserving sharing within a shared-packed forest is applicable not only to GB parsing, but anytime we want to preserve structure sharing in a parse forest in the presence of features