Re: [Haskell-beginners] Design of Webmachine in Haskell

On Mon, Apr 16, 2012 at 6:05 PM, Petar Radosevic wrote:

Hi Michael,

Michael Snoyman writes:

...

When I was at QCon, I heard a talk from Steve Vinoski on Webmachine, and I was surprised to hear how close webmachine was to Haskell already, The concept is basically sticking a state monad on top of WAI. My guess is you would want to use a record type for a Resource, not a typeclass, to make it easier to swap out behaviors. But honestly, I haven't given this any thought since I saw the presentation 6 months ago.

Thanks for your insight, I didn't even consider using record types for a resource. Will also read up upon state monads. I believe that Webmachine passes a dictionary to every function in the HTTP graph[1]. Do you see the state monad having this purpose?

[1]: https://bitbucket.org/justin/webmachine/wiki/BigHTTPGraph -- Petar Radosevic | @wunki

IIRC, each function is passed a dictionary and returns a new dictionary. That's the very essence of a state monad, which is why it could be such a perfect fit here. Of course, I may *not* be remembering correctly. Michael