LR Parsing of CFGs with Restrictions

SUMMARY A method for extending the LR parsing method to enable it to deal with context free grammars containing imbedded restrictions is presented. Such restrictions are usually dealt with in LR based parsers by executing semantic code outside the context of the LR method. By including such restrictions within the LR method itself, potential shift-reduce and reduce-reduce conflicts can be resolved and provide greater control over the language accepted. The proposed method can be easily incorporated into existing LR based parser generating systems.