After you also change your list-ref usage, since that's also erroneous. Perhaps you meant (lambda (ix) (set-member? x ix)) -Ian ----- Original Message ----- From: "Sam Tobin-Hochstadt" <[email protected]> To: [email protected] Cc: "users" <[email protected]> Sent: Friday, December 13, 2013 10:51:31 AM GMT -05:00 US/Canada Eastern Subject: Re: [racket] strange interference with prompt, correcture
I'm pretty sure the problem is that `racket/control` exports a binding named `set`, which is shadowing the regular binding of `set`. If you hide that binding, I think things will work better. Sam On Fri, Dec 13, 2013 at 10:29 AM, <[email protected]> wrote: > > Hello, > > reducing the original code to the example > for containing the problem, i've committed a > slip. The example code should be: > > (define (·first occurrences x L) > (define R (filter (λ(ix) (set-member? (list-ref L ix) x)) L)) > (take R (min (length R) occurrences))) > (print (·first 5 (set #\q #\a #\h) (string->list "this is a sequence."))) > > (prompt (+ 2 (abort 5))) > > (with 'string->list added). It > is failing (in DrRacket) the same way: > > > call-with-continuation-prompt: contract violation > expected: continuation-prompt-tag? > given: #\q > argument position: 2nd > other arguments...: > #<procedure> > #<procedure:...cket/control.rkt:208:45> > > The 'prompt line alone, taken from the > reference, is working perfectly, as in some > other environments also. What is wrong here ? > > Regards, Joost Behrends > > > ____________________ > Racket Users list: > http://lists.racket-lang.org/users ____________________ Racket Users list: http://lists.racket-lang.org/users ____________________ Racket Users list: http://lists.racket-lang.org/users
