[Gretl-devel] scalar function args and NAs

A question has come up as I've thought about user-function arguments (see also http://lists.wfu.edu/pipermail/gretl-devel/2015-July/005850.html ) Given a scalar parameter, what do we want to do if the caller supplies NA as an argument? What difference, if any, should it make if the parameter is marked as "bool" or "int" rather than plain "scalar"? The situation prior to my changes of the last couple of days was that NA was always accepted. But along with fixing the bounds checking for scalar arguments, I banned NA for bool and int parameters. I've now had second thoughts (maybe this would break some existing scripts?) and have reverted to the status quo ante. But maybe this is something we want to think about. Are there real use-cases where a function writer would want to accept NA for a bool or int argument? Or would it be more convenient for the writer not to have to bother with checking for NAs, in the knowledge that they would be ruled out by gretl? Allin