Re: quick bison Q

[Paul Eggert]

> Date: Mon, 09 Dec 2002 10:26:37 -0600
> From: David Durham <address@hidden>
> 
> I really don't think that bison should have to worry about what they
> mean.  It could just find what's between the union keyword and the
> {, remove all the whitespace from that sequence of chars and define
> that as the character sequence of the typename for the union.

I suppose that is what Bison will have to do.  What a pain.

> On the otherhand, you could check what bison 1.35

It allowed any sequence of characters other than '{', which (as far as
I can tell) violates POSIX.  For example, the following Yacc program
conforms to POSIX, and when compiled and run should exit with status
0; but with Bison 1.35 there is a compile-time error message due to
the comment being misparsed.

        %union /* A valid Yacc comment that is not a valid C comment *\
        / because it has *-backslash-newline-/ in it */ 
          {
            int ival;
          };
        %{
          int yylex (void) { return -1; }
        %}
        %%
        s:;

Fixing this bug isn't that hard, but it's not trivial either.  Sigh.


> I'm not sure what is meant by implementation-defined letter?  Is that 
> like a non-US-english character?

Yes.