Re: Grammar analysis

"C. M. Sperberg-McQueen" <cmsmcq@blackmesatech.com> writes:
> We should bear in mind that we can define explicit syntax like 'ε' or
> 'EMPTY-STRING' or '$empty_string' to mean the language consisting of the
> empty string, but we cannot require people to use it, since there is no
> way to prevent people from finding other ways to expres the same idea.

Yes. I think settling on “()” as the minimal way to match an empty
string is probably better than adding a new token for that purpose.

(And FWIW, I don’t think there’s any reason to forbid whitespace or
comments between the parenthesis.)

> But I think we can successfully define the grammar so that the empty
> string in an ixml grammar cannot be used to match the empty string in
> the input string.

That would fix the bug as far as I’m concerned.

                                        Be seeing you,
                                          norm

--
Norm Tovey-Walsh
Saxonica