<div dir="ltr">While +nan.0 is not a Rational, it is a perfectly valid Number so it sort of tickled the question as to whether the intent of '~r' is as a Number formatting procedure or as a Rational formatting procedure. Was just double (no pun intended) checking intent. I could see it going either way.<div> <br></div><div>Thanks,</div><div><br>Ray</div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Mon, Mar 4, 2013 at 2:24 PM, Ryan Culpepper <span dir="ltr"><<a href="mailto:ryanc@ccs.neu.edu" target="_blank">ryanc@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">The contract for '~r' deliberately excludes +nan.0, +inf.0, etc---that's why it's 'rational?' and not 'real?'. The point of '~r' is to provide numeric formatting options, none of which apply to +nan.0, etc.<br> <br> Ryan<div><div class="h5"><br> <br> <br> On 03/04/2013 01:26 PM, Ray Racine wrote:<br> </div></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div class="h5"> Currently the `~r' format routine, which accepts rationals, barfs on<br> +nan.0 and siblings, which are not rationals. My current use case is<br> simply displaying sub-ranges of vectors of flonums. It is not a problem<br> to check for +nan.0 and explicitly display it. I was just wanted to toss<br> it out as a don't know what is the "right thing" for the `~r' format<br> routine to do here.<br> <br> > (define: x : Flonum +nan.0)<br> > (define: y : Flonum 3.145962)<br> > (~r y)<br> - : String<br> "3.145962"<br> > (~r x)<br> ~r: contract violation<br> expected: rational?<br> given: +nan.0<br> ...<br> <br> <br> <br></div></div> ____________________<br> Racket Users list:<br> <a href="http://lists.racket-lang.org/users" target="_blank">http://lists.racket-lang.org/<u></u>users</a><br> <br> </blockquote> <br> </blockquote></div><br></div>