From: Chung jae youn
Subject: symbol question
Date: Wed, 21 Oct 1998 00:00:00 +0000
Message-ID: <yf4iuhfjlmn.fsf@bronze.kaist.ac.kr>

Hello Lispers,
I'm studying lisp and more and more like it.

Anyway, can anybody let me know what the following responses from Lisp
Listener?

  (eq 'content-length 'content-length) => T
  (eq 'content-length (intern "content-length")) => NIL
  (eql 'content-length (intern "content-length")) => NIL
  (equal 'content-length (intern "content-length")) => NIL

Thanks in advance.

-- 
Chung jae youn
··········@pllab.kaist.ac.kr
http://pllab.kaist.ac.kr/~jay

From: David B. Lamkins
Subject: Re: symbol question
Date: Tue, 20 Oct 1998 00:00:00 +0000
Message-ID: <%w2X1.5800$es1.3631558@news.teleport.com>

In article <···············@bronze.kaist.ac.kr> , Chung jae youn
<···@pllab.kaist.ac.kr>  wrote:

>
>Hello Lispers,
>I'm studying lisp and more and more like it.
>
>Anyway, can anybody let me know what the following responses from Lisp
>Listener?
>
>  (eq 'content-length 'content-length) => T
>  (eq 'content-length (intern "content-length")) => NIL
>  (eql 'content-length (intern "content-length")) => NIL
>  (equal 'content-length (intern "content-length")) => NIL
>

eq checks for identical objects.  The other equality comparisons do extra
work, but default to eq for symbols.  

(intern "content-length") is not eq to (intern "CONTENT-LENGTH"); these
return two distinct symbols, named |content-length| and CONTENT-LENGTH.

Have a look at the HyperSpec at
<http://www.harlequin.com/education/books/HyperSpec/>, especially chapters
10 and 11.

---
David B. Lamkins <http://www.teleport.com/~dlamkins/>