Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!usc!apple!sun-barr!lll-winken!arisia!sgi!shinobu!odin!delrey!shap
From: shap@delrey.sgi.com (Jonathan Shapiro)
Newsgroups: comp.object
Subject: Re: Continuations
Message-ID: <1672@odin.SGI.COM>
Date: 29 Nov 89 17:04:47 GMT
References: <2664@bingvaxu.cc.binghamton.edu> <9624@pyr.gatech.EDU> <1623@odin.SGI.COM> <128489@sun.Eng.Sun.COM> <31794@news.Think.COM>
Sender: news@odin.SGI.COM
Organization: Silicon Graphics, Inc., Mountain View, CA
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In article <31794@news.Think.COM> barmar@think.com writes:
>... Scheme is simply the result of adding continuations to Lisp.
>...Upward closures also require similar support.  First-class continuations
>are simply an extension of upward closures to include control information
>as well as variable bindings.

I think you got it right the second time.  The major thing that Scheme
offers is first-class closures (of which functions, continuations, and
in some implementations, environments are examples).  There are also
some miscellaneous alterations, such as eliminating the namespace
distinction between functions and variables, that are a consequence of
making closures first class.

Jon


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