Hi John, It's been several years since I've looked at this, but what happens if you change the require line to:
(require (lifted (only-in 2htdp/image square) square)) (and, I guess, update the constant that you're subtracting from `seconds`)? --Greg On Tue, Jul 30, 2019 at 11:43 AM 'John Clements' via dev-redirect < [email protected]> wrote: > I was messing around with Father Time today and wrote this program: > > (require 2htdp/image) > > (square > (- seconds 1564512004) > "solid" > "blue”) > > I expected to see a growing blue square, but instead got: > > .../lang/prim.rkt:24:44: square: expects a non negative real number as > first argument, given (signal 145 '() #f > #<procedure:...ime/lang-ext.rkt:646:20> 2 #<continuation-mark-set> > #<parameterization> (list (signal 1564512149 '(#<weak-box>) #f > #<procedure:...ime/lang-ext.rkt:467:23> 1 #<continuation-mark-set> > #<parameterization> '()) 156451… > > Somehow the “I’m a signal but I’m also a number” abstraction didn’t quite > flow through the “square” primitive. Is this supposed to work? > > John > > > > > -- > You received this message because you are subscribed to the Google Groups > "Racket Developers" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/racket-dev/c12a06a8-7732-4d11-b4c7-a396967bd759%40mtasv.net > . > -- You received this message because you are subscribed to the Google Groups "Racket Developers" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-dev/CAFm%3DwCdaw9McRxRn7LFiGtZ7QzMaTwfAWwQ2WVsExGZVpoR14w%40mail.gmail.com.
