Extending Functions from Manual Example

[Jason Melbye]

Hi all,

I have been reading through the Bison manual the past couple days.  I really
liked the three examples, especially the last - the multifunction
calculator.  Since reading that I have been wondering if there was a general
way to describe a function that can take on any number of arguments in the
grammer rules?

I suppose that I could just do something like,

| FNCT '(' exp ')'   { $$ = (*($1->value.fnctptr))($3); }
| FNCT '(' exp ',' exp ')'   { $$ = (*($1->value.fnctptr))($3,$5); }
| FNCT '(' exp ',' exp ',' exp ')'   ...


I could go on like that to all for as many arguments as I wanted to / needed
to.  However, I would also like to create a "plug-in" system where users can
create their own functions and add them to the application.  Thus a avoiding
a limit on arguments would be desirable.

Thanks,
Jason