More About Converting BNF to PEG

Parsing Expression Grammar (PEG) encodes a recursive-descent parser with limited backtracking. The parser has many useful properties. Converting PEG to an executable parser is a rather straightforward task. Unfortunately, PEG is not well understood as a language definition tool. It is thus of a practical interest to construct PEGs for languages specified in some familiar way, such as Backus-Naur Form (BNF). The problem was attacked by Medeiros in an elegant way by noticing that both PEG and BNF can be formally defined in a very similar way. Some of his results were extended in a previous paper by this author. We continue here with further extensions.