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From: bobg+@andrew.cmu.edu (Robert Steven Glickstein)
Newsgroups: comp.lang.scheme
Subject: Re: call/cc
Message-ID: <QZyGkmy00Vsn0_xmFV@andrew.cmu.edu>
Date: 10 Mar 90 16:32:50 GMT
References: <1990Mar8.064319.28399@brutus.cs.uiuc.edu>,
	<38402@iuvax.cs.indiana.edu>
Distribution: comp
Organization: Information Technology Center, Carnegie Mellon, Pittsburgh, PA
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In-Reply-To: <38402@iuvax.cs.indiana.edu>


When I was first trying to grok continuations as a Scheme novitiate, I
found the sequence below very enlightening.  Try to understand what's
going on here; I'll post a detailed description in a day or two.

> (define (identity-fn x) x)
> (define (current-continuation) (call/cc identity-fn))
> (define foo (current-continuation))
> foo
#[Continuation]
> (foo 10)
> foo
10

______________
Bob Glickstein                | Internet: bobg@andrew.cmu.edu
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