Re: reduce/reduce error confusing declaration with subscription

[Tom Lieber]

On Sun, Dec 28, 2008 at 6:29 AM, Luca <address@hidden> wrote:
> Yeah it was only an idea, only a an hint! I simply suggest WHERE to modify
> the grammar without introducing conflicts, then you have to do it according
> to your purposes.
...
> Anyway the following productions are what you need:
>
> declaration
>       : declaration_specifiers ';'
>       | declaration_specifiers init_declarator_list ';'
>       | declaration_specifiers array_square init_declarator_list ';'
>       ;
>       
> array_square
>       :
>       '[' constant_expression ']'
>       |array_square '[' constant_expression ']'
>       ;
>
> brackets like "int[4][4] a, b;" are now allowed and correctly parsed!
> You can do the same with pointers!
>
> Once you understand where function declarations are managed, you can also
> fix them.

Thank you, now I see why your comment was more helpful than I thought
it was. I wasn't reading into it at first.

> Anyway I think it is more convenient for you to rewrite a C-like grammar
> subset rather than try to modify the ANSI C grammar according to your
> purposes.
...
> So I thought it was easiest for you to rewrite a grammar, because C grammar
> isn't easy to understand if you never used tools like bison.
...
> I always wrote grammar by myself rather than modify standard grammars; in
> this way I can understand very well all the problems. Of course, this is a
> time expensive way.

I want to be able to do that, but judging by the progress of my (2)
attempts I've gotten much further starting from a working grammar than
from an empty file. It works now, except the conflict.

> As you can read in the "red dragon", it is better to use %left, %prec and
> similar keyword rather than grammar rules, because in the latter way the
> parser has many states.

Ahh, that book has been on my wish list. I think I should finally get it.

-- 
Tom Lieber
http://AllTom.com/