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From: gumby@Cygnus.COM (David Vinayak Wallace)
Newsgroups: comp.lang.lisp
Subject: Re: scope/extent interaction with flet and load
Message-ID: <GUMBY.90Nov3185409@Cygnus.COM>
Date: 4 Nov 90 02:54:09 GMT
References: <60375@bbn.BBN.COM> <1990Oct26.133156@cs.yale.edu>
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In-Reply-To: engelson-sean@cs.yale.edu's message of 26 Oct 90 17:31:56 GMT


   Date: 26 Oct 90 17:31:56 GMT
   From: engelson-sean@cs.yale.edu (Wisp Lizard)

   (let ((old+ #'+)) 
     (setf (symbol-function '+) #'cons)
     (unwind-protect
	 (load "fu")  ; note the correct spelling :-)
       (setf (symbol-function '+) old+))

   Note the use of unwind-protect in case an error occurs while loading.

Yuk.  No need for unwind-protect (and this version should work for
multiprocessing lisps if their letf is implemented correctly):

(letf (((macro-function 'foo) #'cons)) (load "foo"))

I believe letf was added to the revised common lisp.