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Re: [Scheme-reports] Fwd: Comments on draft 6 about call/cc

Jussi Piitulainen scripsit:

> Such things should be considered for the large language now. If they
> can be implemented in terms of the small language, great, let us have
> them as a library, and implementations may be able to do them more
> efficiently. If not, then there are weaknesses in the small language
> that need to be understood and removed.

Let me just comment on your last sentence here.  It is *not* the case that
everything in the large language can or will be implementable in terms
of the small language.  Examples include non-syntax-rules macros, socket
operations and other Posix stuff, procedural records, and weak references.
Some things in the small language reflect the Facade pattern: they may be
implemented in fundamentally different ways in different implementations.

In any case, WG2 has voted to include a delimited-continuations package.
Proposals for such a package (one or more libraries, as required) would
be welcome.

John Cowan   http://ccil.org/~cowan    cowan@x
In might the Feanorians / that swore the unforgotten oath
brought war into Arvernien / with burning and with broken troth.
and Elwing from her fastness dim / then cast her in the waters wide,
but like a mew was swiftly borne, / uplifted o'er the roaring tide.
        --the Earendillinwe

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