Re: continuations in the real world?

[Avi Bryant <address@hidden>]

On Tue, 26 Mar 2002, Matthias Felleisen wrote:

>   What's ironic is that a lot of these sites using "session variables"
>   store them in a way that is no more persistent, distributed, or
>   load-balanced than server-side continuations would be.
>
> Ah, but that's all academic. They use good scripting languages, they make
> money, and that's enough, isn't it? -- Matthias
;-)

Not if you can Beat The Averages and make more money, faster, by using
them.  As I mentioned in the Demystifying Continuations thread, my
recently released web framework at http://beta4.com/seaside makes heavy
use of call/cc - roughly speaking, it's NeXT's WebObjects system,
implemented in Smalltalk, and using continuations for a large part of
session state.  For those who use it, even (especially?) those who know
nothing about continuations, it's not just of academic interest to be able
to layer normal control flow over the HTTP request/response loop and get
transparent backtracking to boot.  I know from personal experience that
the use of continuations has a profound simplifying effect on the
architecture of large web applications, and from what I'm hearing from
early users of the framework, they're discovering the same thing -
smalltalkers may not be used to dealing with full continuations, but they
know good magic when they see it.

Cheers,
Avi