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Re: #f = #none ?

    Date: Thu, 19 Nov 1992 11:41:07 PST
    From: Jim Mayer <mayer@wrc.xerox.com>
    Why is that a problem?  Under the semantics I gave above, #none is a
    perfectly good value.  If no default is given, it is passed right
    through and the "right" thing would happen at the fuction that was
    prepared to do the defaulting.
It suffers from the same punning problems as NIL.  Anytime
you try encoding this out-of-band information in-band in
the data object, you incur risk of punning.  Consider a
compiler or macro cogitating about what to do with this
#none argument.