Why Implementation Matters: Evaluation of an Open-source Constraint Grammar Parser

In recent years, the problem of finite-state constraint grammar (CG) parsing has received renewed attention. Several compilers have been proposed to convert CG rules to finite-state transducers. While these formalisms serve their purpose as proofs of the concept, the performance of the generated transducers lags behind other CG implementations and taggers. In this paper, we argue that the fault lies with using generic finite-state libraries, and not with the formalisms themselves. We present an open-source implementation that capitalises on the characteristics of CG rule application to improve execution time. On smaller grammars our implementation achieves performance comparable to the current open-source state of the art.