help-gnu-emacs
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: why not "stripes" in: (let ((zebra 'stripes) ... ; strings vs symbo


From: Barry Margolin
Subject: Re: why not "stripes" in: (let ((zebra 'stripes) ... ; strings vs symbols?
Date: Mon, 30 Dec 2013 10:27:01 -0500
User-agent: MT-NewsWatcher/3.5.3b3 (Intel Mac OS X)

In article <mailman.10627.1388327081.10748.help-gnu-emacs@gnu.org>,
 Gregor Zattler <telegraph@gmx.net> wrote:

> Dear emacsophiles,
> 
> ATM i read "An Introduction to Programming in Emacs Lisp".  In
> the section where the let function is explained in detail the
> author, Robert J. Chassell, uses this "silly" example:
> 
>      (let ((zebra 'stripes)
>            (tiger 'fierce))
>        (message "One kind of animal has %s and another is %s."
>                 zebra tiger))
> 
> which when evaluated produces "One kind of animal has stripes and
> another is fierce." as output.
> 
> The thing which makes me wonder is why he uses   'stripes   instead
> of "stripes" in this example.  In the output of the message
> function it makes no difference but to me it seems more natural
> to use strings here since they are part of a string in the output...

It may be a (very) old habit. Early versions of Lisp didn't have 
strings. To do what we do now with strings, they would typically use a 
symbols whose print-name is the string, or a list of single-character 
symbols (depending on whether they needed to refer to the string as a 
whole, or needed to extra substrings from it).

-- 
Barry Margolin, barmar@alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***


reply via email to

[Prev in Thread] Current Thread [Next in Thread]