2006 Scheme workshop at ICFP - Jay McCarthy and Shriram Krishnamurthi on continuation passing for web state.

So far this was the best session for me here at the ICFP. We've been hearing a lot about using continuations for keeping state in web applications. This was a good, non overreaching presentation on the subject. It was something of a revelation for me. I was previously under the impression that if you choose the continuation-passing method of preserving state, then you forsake all others. Putting data in cookies, keeping session data in the database (with session id in URLs or in a session variable), putting data directly in session variables... I had thought that this new statefulness required you to kick these to the curb. But it turns out that continuation passing is not jealous. There's no reason not to use them for some of the state in your application and whatever other method for other parts of your state. This is great. Basically you keep using the older methods of state as long as they are working fine for you. It's only when the state becomes problematic (Jay implies that this especially comes up when the user has multiple views of the same data open at once) that you turn to the continuations. Kudos to Jay for being pragmatic about this. Jay's paper (with Shiriram Krishnamurthi) and presentation was based on the the production code they shipped for the PLT Web Server to do these continuations.

Great talk.

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