From ...
From: Erik Naggum <erik@naggum.no>
Subject: Re: case query
Date: 1999/07/02
Message-ID: <3139917376580571@naggum.no>#1/1
X-Deja-AN: 496448772
References: <bcp*zlU3n@news.chiark.greenend.org.uk>
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Organization: Naggum Software; +47 8800 8879; http://www.naggum.no
Newsgroups: comp.lang.lisp

* Mark Carroll <markc@chiark.greenend.org.uk>
| I was surprised to find it refuses, given that (eql nil 'nil) is true.

  I hope you are aware that (eql nil '()) is true.

| Hope I'm not asking too much of this sort of thing - it's just easy to
| fall into bad style in Lisp through not knowing enough to pick a good
| workaround.

  the nature of NIL is perhaps non-obvious, but it is a symbol, the only
  false value, the empty list, and the end-of-list marker.  in this case,
  you're bitten by the identity of NIL and the empty list of keys, which
  does not match anything.  one might argue that it doesn't make sense to
  write cases with no keys, and therefore, NIL-qua-symbol should be used
  instead of NIL-qua-list, but it is this that would be the special case,
  not that NIL is the empty list.

#:Erik
-- 
@1999-07-22T00:37:33Z -- pi billion seconds since the turn of the century