Subject: Re: Must MAPCAR substitute NIL for nothing?
From: Erik Naggum <>
Date: Wed, 21 Nov 2001 19:41:31 GMT
Newsgroups: comp.lang.lisp
Message-ID: <>

* Dr. Edmund Weitz
| have I missed something more basic than the definition of MAPCAR in
| the standard that forces CL to always return (1 NIL 3) in this case?

  Yes.  The primary value of (values) is nil.

| I think it could be convenient to be able to suppress values in such a
| way but maybe you can convince me that I haven't thought deeply enough
| about it.

  Use mapcan and return lists of varying lengths.

  Norway is now run by a priest from the fundamentalist Christian People's
  Party, the fifth largest party representing one eighth of the electorate.
  Carrying a Swiss Army pocket knife in Oslo, Norway, is a criminal offense.