[PPL-devel] client data for ppl_io_set_variable_output_function?

[Enea Zaffanella]

Basile STARYNKEVITCH wrote:
> Hello Roberto and all,
> 
> It would be cute if the routine passed to 
> ppl_io_set_variable_output_function could take some client data.
> 
> So I suggest an additional variant to the API. In C++,  have inside the 
> Parma_Polyhedra_Library::Variable class
>  typedef void output_function_with_data_type (std::ostream &s, const 
> Variable &v, void* data);
> and the static member function
>   set_output_function_with_data(output_function_with_data_type* f, void 
> *data);
> so that when a variable v needs to be output, PPL would call
>   f(s,v,data)
> 
> And in the C API one would have
>   
> ppl_io_set_variable_output_with_data_function(ppl_io_variable_output_function_with_data_type 
> *f, void*data)
> 
> Regards.
> 

Hello.

I think I should be missing something.

Can't you "embed" the access to this supplementary data pointer into 
your own variable output function? That is, you provide an output 
function that, when called, accesses some (possibly many) global data 
pointer(s), rather than a single data pointer passed as a parameter.

Wouldn't that be enough for your purposes?

Cheers,
Enea.