[plt-scheme] Graphics Questions

From: Matthew Flatt (mflatt at cs.utah.edu)
Date: Sun Nov 25 20:01:32 EST 2007

At Sun, 25 Nov 2007 17:52:54 -0700, "Doug Williams" wrote:
> I get an error "continuation application: attempt to cross a continuation
> barrier".  I assume MrEd is using threads or other elements that cause the
> continuation barrier.


> Does anyone have a suggestions?

Delimited continuations. Wrap the body of your callback in

     (lambda ()
       (if *break*
             (set! *break* #f)


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