Path: utzoo!mnetor!uunet!husc6!cmcl2!beta!dzzr
From: dzzr@beta.UUCP (Douglas J Roberts)
Newsgroups: comp.lang.lisp
Subject: Re: Looking for Common Lisp iteration macros
Message-ID: <16786@beta.UUCP>
Date: 21 Mar 88 21:10:23 GMT
References: <23319@ucbvax.BERKELEY.EDU>
Organization: Los Alamos Natl Lab, Los Alamos, N.M.
Lines: 32
Summary: Here's one

In article <23319@ucbvax.BERKELEY.EDU>, mkent@dewey.soe.berkeley.edu (Marty Kent) writes:
> I'm trying to find some reasonable iteration macros for common lisp.  My
> recent experience is with Interlisp, and I've become extremely fond of 
> the very general iteration constructs there (which are not, however, 
> implemented as macros). For-loops, while-loops, etc. are all desireable.
> Please send to me rather than to the net; I'll post a summary to the net


> if I get requests to do so...
Here's one that was bandied about the net a "while" ago.

;;; -*- Mode: LISP; Syntax: Common-lisp; Package: K -*-

(defmacro while (test-form &body body)
  "This macro evaluates test-form, and if the result is non-nil
	   all subsequent forms will be iteratively evaluated until
	   test-form evaluates to nil.
	Example:
		(while (test-form)
			(form1)
			(form2)
			.
			.
			.
			)"
  `(do () ((not ,test-form))
     ,@body))

----------------------------------------------------
Doug Roberts
Los Alamos national Laborotory
dzzr@lanl.gov