> I see in the fbudf declarations that multiple UDF declarations map to
> a single exported function, is there anyway of declaring a UDF
> function that can handle a multitude of parameter types. For example
> could you make firebird handle both NVL(1,1) amd NVL(0.1, 0.1)?

Yes and no.
Result type of UDF is always determined by its declaration.
Otoh, input parameters passed by descriptor can be called with any type,
regardless of declaration (e.g. even if parameter is declared as "int by descriptor",
you can pass string, and UDF will know that the parameter is string).

Ivan