Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!rochester!udel!princeton!phoenix!eliot
From: eliot@phoenix.Princeton.EDU (Eliot Handelman)
Newsgroups: comp.lang.lisp
Subject: Self-referencing Closures
Message-ID: <6859@phoenix.Princeton.EDU>
Date: 6 Mar 89 20:01:06 GMT
Reply-To: eliot@phoenix.Princeton.EDU (Eliot Handelman)
Organization: Princeton University, NJ
Lines: 20


The situation is this: a process, represented as a closure, spawns a 
child, another closure. The parent then runs the child, and when the
child finishes it returns to the parent. I am doing this using continuations,
that is, the child is passed the parent closure which it then funcalls
when it has finished. So the parent has to be able to pass itself to the
child.

I can let a closure reference itself in the following way:

(defun make-closure ()
  (let (-self-)
    (setq -self- #'(lambda ()
		   <this closure can now reference itself as -self->))))

Does this seem like a particularly bad idea? Is there some important reason
why I would not want to do this? Is there some reason why I wouldn't
want to use SETQ? Can this be done more elegantly? All criticism welcome.

Thanks, Eliot