Checking Formals of a Function — h_check_fun

This helper function checks whether a given function fun has required or allowed arguments. The argument check is based only on the names of the arguments. No any further logic is verified here.

Usage

h_check_fun_formals(fun, mandatory = NULL, allowed = NULL)

Arguments

fun: (function)
a function name whose argument names will be checked.
mandatory: (character or NULL)
the names of the arguments which must be present in fun. If mandatory is specified as NULL (default) this requirement is ignored.
allowed: (character or NULL)
the names of the arguments which are allowed in fun. Names that do not belong to allowed are simply not allowed. The allowed parameter is independent from the mandatory, in a sense that if mandatory is specified as a character vector, it does not have to be repeated in allowed. If allowed is specified as NULL (default), then it means that there must be no any arguments in fun (except these ones which are specified in mandatory).