[racket] racket/place seems to be incompatible with DrRacket

From: Robby Findler (robby at eecs.northwestern.edu)
Date: Mon Aug 29 21:32:00 EDT 2011

I think what's happening is that you're creating a place whose first
action is to create that same place again (over and over).


On Mon, Aug 29, 2011 at 8:17 PM, David Mitchell
<dave at fallingcanbedeadly.com> wrote:
> I've been trying to experiment with racket/place, but it seems to have
> significant incompatibilities with DrRacket. I've defined a module based on
> a code snippet in http://www.cs.utah.edu/plt/publications/dls11-tsffd.pdf
> that looks like this:
> #lang racket
> (provide all-defined-out)
> (define (fib n)
>   (define (fib-inner n-remaining i i+1)
>     (if (= n-remaining 1)
>         i+1
>         (fib-inner (- n-remaining 1) i+1 (+ i i+1))))
>   (if (<= n 0)
>       0
>       (fib-inner n 0 1)))
> (define (start-fib n)
>   (define p
>     (place ch
>            (define n (place-channel-get ch))
>            (place-channel-put ch (fib n))))
>   (place-channel-put p n)
>   p)
> (define (super-simple)
>   (define p
>     (place ch
>            (place-channel-put ch 5)))
>   (place-channel-get p))
> If I run racket in my Terminal and load this module, I'm able to use
> start-fib and super-simple as expected. However, if I define this module in
> the DrRacket editor and access the functions through the repl, attempts to
> receive data from either place appear to hang. I'm running OS X Lion, and
> I've tried both the 64-bit and 32-bit versions of 5.1.3, as well as the
> 64-bit version of the latest nightly build (
> I posted a question about this to the IRC channel last night, and one other
> user (jonrafkind) indicated that that the issue could be reproduced on
> 32-bit Linux, so it seems unlikely to be a platform issue. This user also
> indicated, "it seems places keeps reloading the current module."
> (Unfortunately, I am quite new to racket, so I have only a vague idea what
> this means, and no idea at all as to how one would go about discovering such
> a thing)
> Does anyone have any insight as to why this might be failing and/or how I
> might work around it (without abandoning the GUI)?
> _________________________________________________
>  For list-related administrative tasks:
>  http://lists.racket-lang.org/listinfo/users

Posted on the users mailing list.