*MACROARG*

[Robert W. Kerns <RWK at MIT-MC>]

How about something like
(DEFUN FOO (BAR BAZ &OPTIONAL BRAP &LENGTH LENGTH)
   ....)
to access the number of arguments?

Or alternately,
(DEFUN FOO (BAR BAZ &OPTIONAL (BRAP NIL BRAP-P)
   ...)
would bind BRAP-P to T or NIL according to whether or not the optional arg
was supplied.

Or both.  They're not incompatible, and really are more suited for different
cases.

I really don't like the *MACROARG* technique at all.