[racket] overlay and overlay/xy

From: Robby Findler (robby at eecs.northwestern.edu)
Date: Mon Jan 31 06:58:39 EST 2011

In addition to these onlist replies, I have now heard one off-list
reply that is fairly strongly against changing it, pointing out that
people write books that depend on these details.

Possibly adding a new function is the most viable route?


On Sun, Jan 30, 2011 at 10:00 PM, Marc L. Smith <mlsmith at cs.vassar.edu> wrote:
> I taught from HtDP/2e last semester, using 2htdp/image, and had similar
> experiences with my students playing with overlay/xy. I must admit it wasn't
> what I expected after using overlay, and I agree with Don. With the caveat
> that I'm not concerned about backward compatibility, I would prefer to see
> overlay/xy updated to be consistent with overlay, in the way Don described.
> Short of this possibility, a revision to the documentation would also be
> helpful...  :-)
> Thanks to Don for articulating this behavior so well, and to Robby for
> soliciting further opinions!
> Marc
> On Sun, Jan 30, 2011 at 10:33 PM, <users-request at racket-lang.org> wrote:
> Message: 4
> Date: Sun, 30 Jan 2011 21:04:52 -0600
> From: Robby Findler <robby at eecs.northwestern.edu>
> To: Don Blaheta <dblaheta at monm.edu>
> Cc: "users at racket-lang.org" <users at racket-lang.org>
> Subject: Re: [racket] overlay and overlay/xy
> Message-ID:
>        <AANLkTinGAs=xM7GQyjj+q5BLmHMCjMiC_8TNxHn31xJD at mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8
> I find this to be a compelling argument but I am worried about
> backwards compatibilty for others.
> The least I can do is a better job documenting this (and thanks to
> your message I think I'll be able to do that) but I'm not sure about
> changing the semantics.
> Do others that may depend on 2htdp/image have an opinion?
> Robby

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