The Jim Roskind C/C++ Grammar (2018)

It is an honor to see my grammars still being discussed.

These days I work at Amazon, but I can be found on LinkedIn. If contacted with a comment about the grammars (as opposed to a spam missive from a head hunter), I'll typically respond.

What I really need to (finally) do someday is publish my hacks that I added to byacc to increase usability (I think I called it jryacc).

I've always felt that yacc's "error reports" are kindred to having a compiler error listing limited to:

"you have 7 severe errors, 3 errors, and 23 warnings,"

and a reference:

  "to understand the issues, please read the machine code."

With yacc, verbose output suggests (at best) that you read the "state transition diagrams" <ugh> to make sense of "n shift reduce, and m reduce-reduce conflicts."

jryacc provided the shortest sequence of terminals to reach any state, identifies any non-terminal that is both left and right recursive (a common malady in grammar construction, which ensures ambiguity), the shortest sequence of terminals to construct each non-terminal, etc.

...oh... and not to fear... I have copies of the grammars and files mentioned... so hopefully they won't be too lost too soon.

Thanks again for the interesting comments.

Jim

    # Getting back to your example, since you copied the grammar from the ANSI
    # Standard, your grammar is probably wrong.  To expose the problem, try
    # parsing:
    #
    #         typedef int A, B(A); /* my bet is you get a syntax error*/
    #
    # When correctly parsed, the above is equivalent to:
    #
    #         typedef int A;
    #         typedef int B(A);
    #
    # or simply:
    #
    #         typedef int A;
    #         typedef int B(int); /* B's type is function taking an int
    #                 returning and int */