Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!snorkelwacker!ai-lab!zurich.ai.mit.edu!jinx
From: jinx@zurich.ai.mit.edu (Guillermo J. Rozas)
Newsgroups: comp.lang.scheme
Subject: Re: terminology question
Message-ID: <JINX.90Aug22120120@chamarti.ai.mit.edu>
Date: 22 Aug 90 16:01:20 GMT
References: <1466@tub.UUCP> <418@ministry.cambridge.apple.com>
Sender: news@wheaties.ai.mit.edu
Reply-To: jinx@zurich.ai.mit.edu
Organization: M.I.T. Artificial Intelligence Lab.
Lines: 15
In-reply-to: gz@cambridge.apple.com's message of 21 Aug 90 14:48:28 GMT


    In article <1466@tub.UUCP> net@tub.UUCP (Oliver Laumann) writes:
    >One point that distinguishes Scheme's continuations from Classic Lisp's
    >"catch" is that a continuation can be used "jump into" a function that
    >has already returned (i.e. that is not currently "active").
    >
    >What is this property of a continuation called?

    Indefinite extent.  Lisp catch tags have only dynamic extent.

Not quite sufficient.  One can easily imagine continuations that have
indefinite extent but can only be used once.  Dan Friedman and Chris
Haynes wrote a paper about this, but I don't remember the title, etc.

I like to think of Scheme reified continuations as re-entrant.