Hi!
> Le 18 août 2015 à 15:35, Kaz Kylheku <k...@kylheku.com> a écrit :
> While on the topic of POSIX, what does it have to say about
> the y.tab.h header file?
>
> -d Write the header file; by default only the code
> file is written. The #define statements associate the
> token codes assigned by yacc with the user-declared
> token names. This allows source files other than
> y.tab.c to access the token codes.
>
> According to this, y.tab.h is supposed to just #define
> the token codes!
>
> (Unfortunately, the spec forgets the obvious: that lexers
> also need YYSTYPE from y.tab.h, and traditional Yacc
> implementations provide it.)
I'm not reading this as exclusive. It should at least contain
that.
> In any case, users who want who want additional declarations
> can easily write their own header like "y.decl.h". The
> %code functionality for depositing additional material in
> y.tab.h is superfluous, solving a problem that is already
> solved by the C preprocessor, and the fact that you can
> #include your own header between %{ and %} in the grammar
> file. Anyone who has needed a global declaration for yyparse
> (or anything else exported by the .y file) in the past 40
> years probably did exactly that.
That's not entirely true. Things have changed in the meanwhile,
and C, for instance, now has prototypes. And compilers issue
warning when a function is not prototype and is not static for
instance. So I beg to disagree: Bison tries to address today's
needs.
And %code is not superfluous. For instance, we also support
Java. And how do you extend a macro?
