<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><br></div><div>Okay, I distilled it to something small and sent in a bug report. </div><br><div><div>On Jan 6, 2013, at 2:51 PM, Robby Findler wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div dir="ltr">I think maybe you've just found a bug. Do you have a program to share?<div><br></div><div><div>[robby@yanpu] ~/Downloads$ racket</div><div>Welcome to Racket v5.3.1.12.</div><div>> ((contract (-> integer? integer?) (lambda (x) (values 1 2)) 'pos 'neg) 1)</div> <div>stdin::2: broke its contract</div><div> expected 1 value, returned 2 values</div><div> in: the range of</div><div>      (-> integer? integer?)</div><div> contract from: pos</div><div> blaming: pos</div><div>  context...:</div> <div>   /Users/robby/git/plt/collects/racket/contract/private/blame.rkt:89:0: raise-blame-error</div><div>   /Users/robby/git/plt/collects/racket/private/misc.rkt:87:7</div></div><div><br></div></div><div class="gmail_extra"> <br><br><div class="gmail_quote">On Sun, Jan 6, 2013 at 12:26 PM, Matthias Felleisen <span dir="ltr"><<a href="mailto:matthias@ccs.neu.edu" target="_blank">matthias@ccs.neu.edu</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> <br> Is this really the best we can do for a contracted first-order procedure that accidentally returns two values instead of one:<br> <br> Language: racket.<br> . . procedure-result chaperone: arity mismatch;<br>  wrapper does not accept the number of values produced by<br>  the original procedure<br>   wrapper: #<procedure><br>   number of values: 2<br> <br> <br> ??<br> <br> -- Matthias<br> <br> <br> _________________________<br>   Racket Developers list:<br>   <a href="http://lists.racket-lang.org/dev" target="_blank">http://lists.racket-lang.org/dev</a><br> </blockquote></div><br></div> </blockquote></div><br></body></html>