It might be easiest to just use the `image?` predicate from inside the sandbox. Get it out the same way you got the image itself out.
Robby On Tue, May 26, 2020 at 6:22 PM Stephen Foster <step...@thoughtstem.com> wrote: > The following returns #f and #t. How can I get it to return #t and #t? > > Context: I want to allow students to run Racket code on my server. But > when I sandbox their code, I am getting back something that doesn't behave > like a 2htdp/image object. I'm not exactly sure what it is. > > #lang racket > > (require racket/sandbox 2htdp/image) > > (sandbox-path-permissions > (list > '(exists > "/usr/lib/ssl/cert.pem") > '(exists > "/usr/lib/ssl/certs"))) > > (define user-code '(circle 40 'solid 'red)) > > (define circle1 > ((make-evaluator 'racket > `(define f > (let () > ,user-code)) > #:requires > '(2htdp/image)) > 'f)) > > (define circle2 > (circle 40 'solid 'red)) > > (image? circle1) ;#f but I want it to be #t > (image? circle2) ;#t > > > If it helps, when I print out the above values with ~a, I get: > > "#(struct:object:image% ... #(struct:translate 40 40 #(struct:ellipse 80 > 80 0 255 red)) #(struct:bb 80 80 80) #f #f #f #f #t)" > > "#(struct:object:image% ...)" > > -- > You received this message because you are subscribed to the Google Groups > "Racket Users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to racket-users+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/racket-users/ebf8bf84-23d6-45f3-9b1d-6bb6bf592b8e%40googlegroups.com > <https://groups.google.com/d/msgid/racket-users/ebf8bf84-23d6-45f3-9b1d-6bb6bf592b8e%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/CAL3TdOP%3Diwf5PvNk6myn1i4b0qvgx2mC82m2GLKavPqQTxcVaw%40mail.gmail.com.
