Re: Retrieving the last "$$"

[F van der Meeren]

On 23 Jul 2009, at 17:53, Joel E. Denny wrote:

> On Thu, 23 Jul 2009, Filip van der Meeren wrote:
>
> > I am using bisons yypush_parse to evaluate my text.
>
> Given that Bison's push parsing feature is relatively new, we're  
> eager to
> find out what you're using it for.  Is it working well for you so far?

I am using it to parse csh-scripts (the shell), to create a live step  
through engine, that since the csh-language itself doesn't provide the  
features needed to debug (bash does).
I am planning to launch it on Sourceforge (or alike) from the minute I  
have a working beta...

> > But when the parser has finished parsing, I need to get a hold on  
> > the last
> > "$$".
>
> By "the last $$", do you mean the semantic value of the start symbol?
> One way is to add a new start symbol and rule:

By "$$" I mean the last semantic value that has been constructed by  
the many grammar rules. The application is window-based, so there will  
be more than one instance at any given time.

>  start_new: start_old { /* access $1 here */ } ;
>
> > Do you have any idea how to retrieve the $$ when using bison 2.4.1  
> > with the
> > %define api.pure, %define api.push_pull "push" defined ?
>
> I can't think of any difference between push and pull parsing for this
> issue.