Forgive me for what is probably a tired old FAQ, but why did the CL
committee decide not to include call-with-current-continuation? Was
there some particular reason not to put it in? Was it an oversight?
Might it appear in later editions?
Thanks,
E.
In article <····················@elroy.jpl.nasa.gov> ···@robotics.jpl (Erann Gat) writes:
>Forgive me for what is probably a tired old FAQ, but why did the CL
>committee decide not to include call-with-current-continuation? Was
>there some particular reason not to put it in? Was it an oversight?
It wasn't deemed necessary. Compared to Scheme, Common Lisp support of
lexical closures is limited. For example, control transfer targets are
only valid during the dynamic extents of the forms that defines them,
whereas Scheme allows transfering back into such constructs after they have
exited. Since call/cc is primarily concerned with such control closures,
there's not as much need for it in CL.
A downward-only call/cc can be defined in Common Lisp using existing
constructs.
>Might it appear in later editions?
No one in X3J13 has suggested adding it.
--
Barry Margolin, Thinking Machines Corp.
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