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Message from discussion I never realized the funny difference between nil and () before.
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Ankur  
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 More options Nov 3 2011, 1:12 am
Newsgroups: comp.lang.lisp
From: Ankur <an...@lipidity.com>
Date: Thu, 03 Nov 2011 05:12:21 GMT
Local: Thurs, Nov 3 2011 1:12 am
Subject: Re: I never realized the funny difference between nil and () before.
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* fortunatus <daniel.elia...@excite.com>

> I find the basic concept a little odd in itself:

> CL-USER> (symbolp 'nil)
> T                       <-- no sweat
> CL-USER> (symbolp nil)
> T                       <-- kind of freaky...

[1]> (symbolp ':hi)
T
[2]> (symbolp :hi)
T

> CL-USER> (symbolp '( ))
> T                       <-- this freaks me out!!
> CL-USER> (symbolp ( ))
> T

Why? () is the same as NIL, isn't it?

> CL-USER> (symbolp '( nil ))
> NIL                     <-- finally back to normalcy - whew

(listp '(nil)) => T

It's a list with one element.

> A list is not a symbol but the empty list is a symbol?!!  The nothing-
> value is a symbol?  That freaks me out!

It's defined that way, isn't it? What's freaky about it?

--
Ankur


 
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