[racket] Question about syntax splicing and formatting of the resulting code body

Sorry off topic, but Forward Production Rete Rules Engines, such fond
memories.   An exact blueprint to code one from scratch is below.  Jess is
license encumbered, Drools is not, but I expect you've already run across
it.

And many, many moons long gone, I did an impl in SML that compiled under
MLton  which was PDQ.  Then a buddy of mine with some assistance did what
is AFAIK still the only mult-threaded / concurrent implementation (in Java)
of a Reta alpha/beta network using a sort of "zipper" algo on the network
graph.  It's still out there http://www.zilonis.org/ , not used by anyone
AFAIK, though we believe a few folks did take the code internally.   We had
it in production for awhile long ago (ad targeting on web).   Rumor was
Forgy also built a concurrent solution, but you had to model the Rete in a
DSL and it compiled to Java code.  Never caught on.

Oh and yes of course, the Zilonis version has a "tiny" scheme interpreter
built in to write capable of simple calculations, regex matches etc in the
rules.
Production Matching for Large Learning Systems
(Rete/UL)<http://docs.codehaus.org/download/attachments/8082/CMU-CS-95-113.pdf?version=1&modificationDate=1092858118000>


by Robert B. Doorenbos


On Wed, Jan 9, 2013 at 8:36 AM, Grant Rettke <grettke at acm.org> wrote:

> Hi,
>
> I have the goal of inserting some Jess (http://herzberg.ca.sandia.gov/)
> code inside of a Scribble interaction environment (eventually I will have a
> language to evaluate this but I'm not there yet). Here is the relevant part
> of the code I have to do that:
>
> #lang racket
>
> (define (my-read-syntax src in)
>   (define path-ls (get-path in))
>   (define path (list->string path-ls))
>   (define fis (open-input-file #:mode 'text path))
>   (define datums (let loop ()
>                    (let* ((datum (read fis)))
>                      (cond ((eof-object? datum) empty)
>                            (else (cons datum (loop)))))))
>   (close-input-port fis)
>   (datum->syntax #f datums))
>
> This does load the file and insert it into Scribble eg:
>
> (interaction
>     #:eval
>     my-evaluator
>     ((watch all)
>      (reset)
>      (defrule do-anything "A rule for anything." ?ne <- (anything) =>
> (printout t "Someone did something.") (retract ?ne))
>      (assert (anything))
>      (run)))))
>
> There are two things I'm still not doing correctly though:
>
> #1. I've collected the contents of that file into a list of datums that
> looks like this in DrRacket's console:
>
> '((watch all)
>   (reset)
>   (defrule
>    do-anything
>    "A rule for anything."
>    ?ne
>    <-
>    (anything)
>    =>
>    (printout t "Someone did something.")
>    (retract ?ne))
>   (assert (anything))
>   (run))
>
> I don't want those inserted as a list though, I only want the contents
> inserted. Up above I see why it is happening, but I am not successfully
> splicing it in my attempts. What is the right way?
>
> #2. The code body is formatted at least in the output in DrRacket. When it
> is inserted into the Scribble environment, though, it loses some of it's
> formatting namely the defrule and right arrow appear in the same line. That
> said, when Scribble renders it, all of the code is rendered on the same
> line like this:
>
> > ((watchall)(reset)(defruledo-anything"A rule for anything."?ne<-(
> anything)=>(printoutt"Someone did something.")(retract?ne))(assert(
> anything))(run))
>
> =>: arrow not allowed as an expression
>
> How may I read in that file and then generated a syntax object that
> retains the indentation and new lines?
>
> #3. Am I generally going about this in an OK manner? My next part of the
> plan to make a simple language whose only purpose in life is to evaluate
> Jess code and print out the results; I want to be able to use Scribble for
> any other Lispy language out there at least the interaction environment.
>
> ____________________
>   Racket Users list:
>   http://lists.racket-lang.org/users
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.racket-lang.org/users/archive/attachments/20130109/007356a4/attachment-0001.html>