Seeking Continuations Links

Myself and a few others are trying to get together a “Playing Around
with Continuations” project. As a start, we are collecting any
resources we can find about them.

If you have links to any continuations related material, would you
please reply and post them here. I will start us off:

General Definition –
Continuation - Wikipedia

Ruby Based Tutorials –
http://www.rubygarden.org/ruby?Continuations
http://www.deepwood.net/~mikael/continuations/

Ruby Examples –
eigenclass.org
+grasp+than+2ch

Ruby Projects Using (at least some) Continuations –
http://rubyforge.org/projects/wee/

Other Languages –
http://www.intertwingly.net/blog/2005/04/13/Continuations-for-
Curmudgeons

Thanks for any links you can provide.

James Edward G. II

On Thu, 2 Feb 2006, James Edward G. II wrote:

Ruby Based Tutorials –
Other Languages –
Continuations for Curmudgeons

Thanks for any links you can provide.

http://lambda-the-ultimate.org/node/1036

http://www.google.com/search?as_q=continuation&num=100&hl=en&btnG=Google+Search&as_epq=&as_oq=&as_eq=&lr=&as_ft=i&as_filetype=&as_qdr=all&as_occt=any&as_dt=i&as_sitesearch=http%3A%2F%2Fcaml.inria.fr&as_rights=&safe=images

trying to get a headache james? :wink:

regards.

-a

James Edward G. II [email protected] wrote:

Myself and a few others are trying to get together a “Playing Around
with Continuations” project. As a start, we are collecting any
resources we can find about them.

If you have links to any continuations related material, would you
please reply and post them here. I will start us off:

Don’t miss the classic “sandwich” post:

http://groups.google.com/group/perl.perl6.language/msg/b0cfa757f0ce1cfd

martin

James Edward G. II wrote:

Myself and a few others are trying to get together a “Playing Around
with Continuations” project. As a start, we are collecting any
resources we can find about them.

Is there a an online copy (video, I hope) of the continuations talk by
Jim W. and Chad F. from RubyConf05?

It was really quite good.


James B.

“Blanket statements are over-rated”

James Edward G. II ha scritto:

If you have links to any continuations related material, would you
please reply and post them here. I will start us off:

maybe useful:
http://c2.com/cgi/wiki?CallWithCurrentContinuation (and linked)
Understanding continuations | Lambda the Ultimate
http://www.sidhe.org/~dan/blog/archives/000185.html
A page about call/cc

Also, I have a page in italian about a small part of what Kernel#callc
is… but I don’t think it is worth adding the link :slight_smile:

On Feb 1, 2006, at 4:21 PM, [email protected] wrote:

trying to get a headache james? :wink:

Probably.

I guess we figured there was safety in numbers, so… well… we
could get headaches together. :slight_smile:

Thanks all for the terrific links.

James Edward G. II

Headaches for all!

I have a feeling that contiuations are an excellent solution for a
problem I haven’t found yet. Though I want to find this problem,
because I have a suspiscion that using continuations to solve it will
make me feel much cooler :wink:

.adam

On Feb 1, 2006, at 4:30 PM, James B. wrote:


James B.

“Blanket statements are over-rated”

Folks-

The video and audio from rubyconf 05 is still available on my blog:

http://brainspl.at/articles/2005/12/01/rubyconf-files-resurrected

And the Weirich and Fowler contibuations movie is here:

http://yhrhosting.com/rubyconf/FowlerAndWeirich240S.mov

Enjoy!
-Ezra

On Feb 2, 2006, at 12:48 PM, Ezra Z. wrote:

Folks-

The video and audio from rubyconf 05 is still available on my blog:

Ruby on Rails Blog / What is Ruby on Rails for?

And the Weirich and Fowler contibuations movie is here:

http://yhrhosting.com/rubyconf/FowlerAndWeirich240S.mov

Are the unit tests from this talk, like when they implemented catch/
throw, available anywhere?

James Edward G. II

On Feb 2, 2006, at 4:59 PM, Wilson B. wrote:

Yep:
http://onestepback.org/articles/callcc/throw_catch/

I had the pleasure of attending that workshop. Very cool.

Wow, thank you. Trickiest 27 lines of code I ever wrote. :slight_smile:

James Edward G. II

On 2/2/06, James Edward G. II [email protected] wrote:

http://yhrhosting.com/rubyconf/FowlerAndWeirich240S.mov

Are the unit tests from this talk, like when they implemented catch/
throw, available anywhere?

Yep:
http://onestepback.org/articles/callcc/throw_catch/

I had the pleasure of attending that workshop. Very cool.

On 2/1/06, James Edward G. II [email protected] wrote:

Myself and a few others are trying to get together a “Playing Around
with Continuations” project. As a start, we are collecting any
resources we can find about them.

I don’t have a link, but last night a buddy and I found a cool usage for
continuations and AOP in implementing a network simulator. The general
idea
might work for testing drb code as well, although we haven’t gone that
far
yet.

Our simulator is a typical discrete event based simulator, and
previously we
had been using messages (packets) to communicate between virtual nodes
in
the network. For our current project we wanted to implement a p2p
algorithm
in an rpc style though, which seemingly would require us to implement
proxy
objects for everything that would send messages so it can all go through
the
simulator. Then we realized that by just wrapping any methods which
should
be treated as “remote” with some message passing code we could possibly
use
the same code for simulation as for an implementation (yet to be
verified on
anything real…). Either way this saves a lot of time, and after some
initial unit testing it seems to be working correctly. Here is the
wrapper
method, which hopefully shows how it is working: (It’s shorter than it
looks. Mostly just comments so a couple months down the line these
continuations don’t require another neural re-wiring :slight_smile:


module GoSim
module Net
# Wrap the methods of a class so they are called through the
# network simulator.
def Net.remote_method(clazz, *methods)
methods.each do |meth|

    # Store the original method so we can call it eventually.
    original = clazz.instance_method(meth)
    clazz.instance_eval do

      # Define a new method with the same name, which sends
      # a message on the call and then another on the return.
      define_method(meth) do |*a|

        # Save a continuation to return to this point when the
        # event fires at a later time.
        cont = nil
        from_sched = callcc {|cont|}

        # Post the message event and jump back into the
        # event scheduling loop. Note that from_sched will be
        # true when the continuation is called later.
        GoSim::Net::Topology.instance.
          transmit_continuation(cont) unless from_sched

        # Make the actual method call
        retval = original.bind(self).call(*a)

        # Now do it over again for the return value.
        cont = nil
        ret = callcc {|cont|}
        GoSim::Net::Topology.instance.
          transmit_continuation(cont) if ret.nil?

        retval
      end
    end
  end
end # def remote_method

end # Net
end # GoSim

Make sense? Think this could work to simulate a bunch of drb objects
communicating with each other? Could be a handy way to unit test
distributed applications etc…

-Jeff