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 < d...@plt-scheme.org> 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 racket-dev+unsubscr...@googlegroups.com. > 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 racket-dev+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-dev/CAFm%3DwCdaw9McRxRn7LFiGtZ7QzMaTwfAWwQ2WVsExGZVpoR14w%40mail.gmail.com.
