Rebol [
    Title: "Nargs"
    File: %nargs.r
    Date: 14/12/2002/15:21
    Author: "Carl Sassenrath"
]

nargs: func [
    {The number of the function arguments}
    f [any-function!]
] [
    -1 + index? any [find first :f refinement! tail first :f]
]

comment [
    Example:

    nargs :-
]