Re: [Chicken-users] amb egg bug/confusion

[Alan Post]

On Mon, Mar 19, 2012 at 09:18:29AM -0700, Matt Welland wrote:
>    On Mon, Mar 19, 2012 at 5:55 AM, Alan Post
>    <address@hidden> wrote:
> 
>      On Thu, Mar 15, 2012 at 01:38:19AM +0100, Thomas Chust wrote:
>      > On Wed, 2012-03-14 at 18:23 -0600, Alan Post wrote:
>      > > [...]
>      > > * (pretty-print (let ((s (amb 0 1 2))) (amb-collect s)))
>      > > [...]
>      > > produces:
>      > > [...]
>      > > * (0)
>      > > [...]
>      >
>      > Hello,
>      >
>      > to me this behaviour looks correct. amb-collect is supposed to collect
>      > all the different values its argument can take on, but in your example
>      s
>      > is not an ambivalent expression -- the fact that s is bound to a value
>      > produced by amb only makes the let expression ambivalent.
>      >
>      > To phrase it more technically: Every amb-collect creates a new dynamic
>      > scope for backtracking. Any ambivalence introduced in that dynamic
>      scope
>      > will be resolved and the results will be collected but any outer
>      dynamic
>      > scope will not be affected.
>      >
> 
>      Thomas, John,
> 
>      Thank you both very much. *I did manage to start properly using the
>      amb egg, and completed a one-off homework assignment:
> 
>      
> [2]https://github.com/alanpost/permaculture-design-course/blob/master/guild/README
> 
>      amb is very neat. *I'll likely throw larger datasets and more
>      interesting constraints at it as I continue to explore this
>      problem space.
> 
>    Wow, another permaculturist on the chicken scheme list, what is the
>    probability of that? I got my design certification just over a year ago.
>    Nice work on the guild design! Do you have further plans for the code?
>    *
> 

Ossum!  I'm inclined to agree with Jorg and say it's because it's
*Chicken* Scheme.  >_> 

I do have further plans for the code.  I'm taking a 7-weekend
course, with 2 weeknds left.  I won't be working on it again
until I finish the course, which happens at the end of April.

I'm not sure in which direction I'll go first: it really depends
on which problem in front of me I have the best data on.  This
project convinced me that I needed to start compiling and collecting
such data: the constraint exploration was the finishing touch and
my playground, and the more data I have the more options I have
to play with.

A local-to-me ecologist is interested in sitting down and
brainstorming, I hope something interesting comes of that. 

-Alan
-- 
.i ma'a lo bradi cu penmi gi'e du