Re: How to clear parser variables between invocations of ->parse()?

On Wed, Oct 09, 2002 at 09:56:11AM -0400, Ted Zlatanov wrote:
> On Tue, 8 Oct 2002, [email protected] wrote:
> > It works great, except I need to clear %variables between calls to
> > $parse->eqns.  I realize that in this instance that:
> > 
> > $list = ();
> > 
> > works, but it doesn't feel right.  Something cleaner would be nicer.
> > I'd also prefer not to use a global in the main package instead of
> > the private namespace variable.
> > 
> > Isn't there a more encapsulated way to either clear the private
> > variable or have a different solution?
> 
> I may be missing something, but why not use a function instead of the
> eqns rule?
> 
> sub run_equation { $parse->clear(); $parse->eqns(@_); };
> 
> and then in the grammar implement a clear() rule to clear the
> variables.

Thanks, that works well, aside from this happening:

Use of uninitialized value in index at /users/ckuskie/perl/modules/Parse/RecDescent.pm line 2979.
Use of uninitialized value in index at /users/ckuskie/perl/modules/Parse/RecDescent.pm line 2979.
Use of uninitialized value in length at /users/ckuskie/perl/modules/Parse/RecDescent.pm line 2734.
Use of uninitialized value in substitution (s///) at (eval 21) line 1076.
Use of uninitialized value in substitution (s///) at (eval 21) line 1076.

You have to pass the rule something to work with:

$parse->clear('');

Colin