Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!think!barmar
From: barmar@think.COM (Barry Margolin)
Newsgroups: comp.lang.lisp
Subject: Re: Self-referencing Closures
Message-ID: <37134@think.UUCP>
Date: 7 Mar 89 18:15:54 GMT
References: <6859@phoenix.Princeton.EDU> <52880@yale-celray.yale.UUCP>
Sender: news@think.UUCP
Reply-To: barmar@kulla.think.com.UUCP (Barry Margolin)
Organization: Thinking Machines Corporation, Cambridge, MA
Lines: 19

In article <52880@yale-celray.yale.UUCP> Krulwich-Bruce@cs.yale.edu (Bruce Krulwich) writes:
>	(defun make-closure ()
>	  (labels ((-self- () <code that can reference -self-> ))
>	    -self-))

Actually, the last form should be #'-self-, since LABELS binds the
functional value, not the variable value, of the symbol.

>If you really tend towards the boroque you can use "Church's Y operator" which
>is defined in Scheme using:

You could also simply use LETREC in Scheme.  It binds a variable and
arranges for the scope to include the value form.

Barry Margolin
Thinking Machines Corp.

barmar@think.com
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