{
    "comment": "Basic grammar that contains a nullable A nonterminal.",

    "lex": {
        "rules": [
           ["\\s+", "/* skip whitespace */"],
           ["x", "return 'x';"]
        ]
    },

    "tokens": "x",
    "bnf": {
        "A" :[ "A x",
               "" ]
    }
}