callcc/cps-style programming

[STARYNKEVITCH Basile <Basile.Starynkevitch@cea.fr>]

>>>>> "Joe" == Joe Lisp <joelisp@yahoo.com> writes:

    Joe> Is anyone working on callcc for OCaml?  

I am not working on it (although I would like to...) 

However, adding explicit continuations to Ocaml is an important task:

the naive approach -a la Appel 1989, like SML/NJ0.93- would be to
reify all continuations, ie to replace call frames by explicit
continuation closures. This means drastically changing both the
runtime (garbage collector) and the compiler system. Also, this would
slow down every OCaml application (probably by at least 10%) - but
call/cc would be rather fast (since in constant time)

another approach is to segment the call stack, and to copy the call
stack on each call/cc. This also require a GC change and probably some
(easier) compiler change. However, each call/cc would take a time
proportional to the call stack depth (which is copied). Calling a
continuation obtained by call/cc would also require copying a stack segment.

What I am missing more is the ability to dynamically load some
compiled functions (at least the Dynlink package implemented in the
native code ocamlopt, with ability to dynamically load native machine
code generated by ocamlopt; ideally I would even like to generate
garbage collected code on the fly and be able to call and marshall it)

Regards.

N.B. Any opinions expressed here are only mine, and not of my organization.
N.B. Les opinions exprimees ici me sont personnelles et n engagent pas le CEA.

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