Checks an object to determine if it is a nimbleFunction (i.e., a function created by nimbleFunction
using setup code).
is.nf(f, inputIsName = FALSE, where = -1)
object to be tested
logical indicating whether the function is provided as the character name of the function or the function object itself
Optional argument needed due to R package namespace issues but which should not need to be provided by a user.
nimbleFunction
for how to create a nimbleFunction