BNFC does not support \r and \f (lexer error)

[andreasabel]

BNFC chokes on a definition like the following in the grammar file.

token Name (char - [ "-(){};.@\" \n\r\t\f" ]) + ;

The reason is that the BNF lexer does handle \r (carriage return) and \f (form feed).

[jchook]

This seems like a critical issue.

If I cherry-pick your commits, will it fix this issue?

Also it appears BNFC does not support grammars with \0.

[andreasabel]

I now merged my PR. Let me know if there are problems still.