[Snow-users-list] [gambit-list] AWS, Termite, and Snow

Marc Feeley feeley at iro.umontreal.ca
Wed Jan 30 00:05:34 EST 2008

On 29-Jan-08, at 11:29 PM, Joe Hosteny wrote:

> Hi all,
> 	First of all, let me preface this email with a disclaimer. I'm fairly
> new (again) to Scheme (last exposure was 10+ years ago in college).
> I'm still feeling my way around a bit, and have settled on Gambit,
> Chicken, and PLT, to a lesser extent. What I'm trying to say is - dumb
> questions may follow!
> 	I recently wrote a library to manage a cluster of machines in
> Amazon's EC2. I'm looking to totally rewrite it, and port it to Scheme
> in the process. I was also looking at having some facility for
> managing the cluster from within, with event monitoring via SQS or
> Termite. Currently, the library does that via polling from a machine
> external to the cluster. It's not ideal, but was sufficient to get my
> application working.
> 	As a start, I wrote a simple Snow package to do MD5 and SHA1 HMAC
> calculations (the AWS query string API uses SHA1 signatures).

The "digest" Snow package does MD5, SHA1, and other digests:


> I
> started to look around for some utilities for URI parsing and encoding
> for use in Gambit, but didn't seem to find anything. So, first
> question - is anyone aware of a suitable package for this?

Check examples/web-server/http.scm in the Gambit distribution.

> Second
> question - if one doesn't exist, what do people do for regular
> expression parsing in Gambit?

I normally use pregexp: http://www.ccs.neu.edu/home/dorai/pregexp/pregexp.html 

It is well written and portable, so it shouldn't be hard to turn it  
into a Snow module.

> 	Since I haven't really fleshed out the new architecture, I'm not sure
> it's a requirement that I host code to both communicate events across
> the cluster and issue AWS API calls from within the same executable.
> So I guess an option would be to use Chicken for the HTTP stuff, and
> Gambit for Termite and making calls to the code written with Chicken
> (though at that point, it may make sense to just use one of the Ruby
> or Java libs for that part). I'd prefer not to, if for nothing more
> than to be able to contribute the AWS portion as a Chicken or Snow
> package.
> 	So, a few general questions follow. From recent mailing list
> discussions, it sounds like Termite will be targeted towards Gambit
> only, for the time being at least. Guillaume, is that correct? If not,
> do you have an idea of when it might be seen on other Schemes
> (specifically, Chicken or PLT)?
> 	Also, does anyone have a feel for what is going on with Snow? It
> seems like the traffic on the mailing list is a bit slow, and the
> number of packages is still relatively few.

I'm still very much interested in continuing to develop Snow.  However  
I've been busy with other things recently and hope to get back to  
maintaining Snow more actively soon.  To ease the workload I'm also  
looking for someone to take on some of the maintenance tasks.  Is  
anyone interested in getting involved?


More information about the Snow-users-list mailing list