Path: utzoo!yunexus!ists!jarvis.csri.toronto.edu!mailrus!hellgate.utah.edu!cdr.utah.edu!moore
From: moore%cdr.utah.edu@cs.utah.edu (Tim Moore)
Newsgroups: comp.lang.lisp
Subject: Re: code
Message-ID: <1989Nov18.182509.14667@hellgate.utah.edu>
Date: 19 Nov 89 01:25:08 GMT
Article-I.D.: hellgate.1989Nov18.182509.14667
References: <464@cs.columbia.edu> <1989Nov18.152356.7962@hellgate.utah.edu>
Organization: University of Utah CS Dept
Lines: 24

In article <1989Nov18.152356.7962@hellgate.utah.edu> moore%cdr.utah.edu@cs.utah.edu (Tim Moore) writes:
>
>If you want persistant lexical bindings you probably should be using closures
>instead. Here's you fibonacci example, rewritten to use a closure:
>
>(defun fib-setup (&key ((:n-2 pn-2) 0) ((:n-1 pn-1) 1))
>  #'(lambda (&key n-2 n-1)
>      (and n-2 (setq pn-2 n2))
>      (and n-1 (setq pn-1 n1))
>      (psetq pn-2 pn-1 pn-1 (+ pn-2 pn-1))
>      pn-1))

Oops! That should be:

(defun fib-setup (&key ((:n-2 pn-2) 0) ((:n-1 pn-1) 1))
  #'(lambda (&key n-2 n-1)
      (and n-2 (setq pn-2 n-2))
      (and n-1 (setq pn-1 n-1))
      (psetq pn-2 pn-1 pn-1 (+ pn-2 pn-1))
      pn-1))

Tim Moore                     moore@cs.utah.edu {bellcore,hplabs}!utah-cs!moore
"Ah, youth. Ah, statute of limitations."
		-John Waters