Re: a noob question

From: Paul F. Dietz (dietz_at_dls.net)
Date: 01/23/05 

Date: Sun, 23 Jan 2005 16:38:48 -0600

Michael Beattie wrote:
> Why is it that some macros or whatever have double parens around them?
> Like...
>
> (let ((x 2))) ; this has 2 parens around the x=2 assignment
>
> or
>
> (do ((i 0 (+ i 1))) ; there's 2 parens around the i=0 and the increment
> ((> i 10) 'done) ; 2 parens around the "end" condition
> (print i))
>
> I guess part of the question is "what exactly is the template for the do
> or let macro?"

Because these can have more than one binding.

   (let ((x 1) (y 2)) (+ x y)) ==> 3

The end condition of DO is grouped with the end form(s), so it doesn't get
confused with the body of the DO.

        Paul

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