Re: Type checking in semantic actions

[Hans Aberg]

On 15 Feb 2010, at 22:25, Michael Budach wrote:

> > So you need to assign config_spec a valid value somewhere, or write a
> > rule that initializes $$ instead of the default rule.
>
> Does that mean it is possible to redefine the default rule from
> "$$ = $1;" to e.g. "$$=NULL;" ?
>
> Can you tell me how ? I did not find anything like that in the  
> documentation.

You can change the skeleton file. This is a hack, because when it is  
developed, if you want a new, you need to tweak it to get it updated.  
But if you have some suggestions, and there is a general interest, it  
might be integrated.

Anyway, the skeleton files are on my system located in /usr/local/ 
share/bison/. Copy the one you want to use, and in it, look for a  
statement:
  switch (n_) {
    default:
      ...
  }
Change the ... to what you want it to be.

Then add %skeleton "<filename>" to your .y file. It will look for it  
in the same directory, or some of the common locations.

  Hans