Re: [Math / Special Functions] Use more than one user_error function?

From: John Maddock (jz.maddock_at_[hidden])
Date: 2022-04-14 10:32:04

> That's actually a very good question, as things stand, I think the 
> only way you can know what the caller is, is to check the string name 
> passed to the error handler.  It is possibly "worse" than that too as 
> some special functions can call other special functions internally, so 
> in a few rare cases, if something has gone badly wrong in the "outer" 
> function, the actual error may be generated in the "inner" function :(
>
> But leaving aside that issue for the moment, I would probably create a 
> sorted table of std::pair<const char* const char*>, with the first 
> member of the pair being our name, the second your name, and then do a 
> std:::lower_bound to find a matching entry and do the name 
> translation.  I don't think our names have ever changed, so while 
> we've never guaranteed stability of those, it's hard to imagine them 
> changing unless someone spots a really grievous spelling mistake or 
> something ;)Â  You would still need to perform the rather tedious job 
> of calling each function you're wrapping with say NaN parameters, and 
> then logging the string name of the function in the error handler so 
> you know what to put in the table.

Maybe we're both over-thinking this, why not just:

double erfinv_double(double x)

{

 Â Â Â Â  try{

 Â Â Â Â Â Â Â Â  return erf_inv(x, special_policy());

 Â Â  }

 Â Â  catch(const std::domain_error&)

 Â Â  {

 Â Â Â Â Â  // Python error handling here.

 Â Â  }

 Â Â  catch(whatever-else-may-get-thrown){ /*more error handling*/}

}

?