All dynamic/c does is apply three contracts in a particular order where one is dynamic.<div><br></div><div>coerce/c strongly implies that the function is coercion, but its implementation is similar to how the contract system must already use projection functions (ie it cannot confirm that are actually projections; it just applies them and uses the result)</div> <div><br></div><div>The default value of current-response/c is a projection (any/c)</div><div><br></div><div>The compatibility library does not provide anything with the /c suffix that is a coercion --- it gives normalize-response and automatically sets current-response/c, but doesn't give anything that implies it is a "contract"</div> <div><br></div><div>Thus, the only thing that IMHO should irk you is xexpr-response/c that has the /c suffix and uses coerce/c with an actual coercion. Is that the case? What do you want me to call it?</div><div><br></div> <div>Jay<br><br><div class="gmail_quote">On Sun, Dec 5, 2010 at 6:46 AM, Robby Findler <span dir="ltr"><<a href="mailto:robby@eecs.northwestern.edu">robby@eecs.northwestern.edu</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"> You've made a contract that isn't a projection, but does a coercion?<br> <br> I'd be happier if you instead made your own separate wrappers and<br> didn't use "/c" and didn't call this a contract.<br> <font color="#888888"><br> Robby<br> </font><div><div></div><div class="h5"><br> On Sun, Dec 5, 2010 at 12:29 AM, Jay McCarthy <<a href="mailto:jay.mccarthy@gmail.com">jay.mccarthy@gmail.com</a>> wrote:<br> > Giving special consideration to Eli and YC's perspectives, I've come up with<br> > the following way out of this problem.<br> > I found a way to provide a global hook that is tasteful to me. I've created<br> > "dynamic/c". Here's a little example:<br> > Examples:<br> > (define p (make-parameter any/c))<br> > (define c (dynamic/c string? p number?))<br> > > (contract c "123" 'pos 'neg)<br> > pos broke the contract<br> > (dynamic<br> > string?<br> > #<procedure:parameter-procedure><br> > number?)<br> > on eval:5:0; expected <number?>, given: "123"<br> > > (p (coerce/c string->number))<br> > > (contract c "123" 'pos 'neg)<br> > 123<br> > > (contract c "123a" 'pos 'neg)<br> > pos broke the contract<br> > (dynamic<br> > string?<br> > #<procedure:parameter-procedure><br> > number?)<br> > on eval:8:0; Coercion failed<br> > The Web Server will define response/c as (dynamic/c any/c current-response/c<br> > response?) and provide the current-response/c parameter for customization.<br> > The default will be no coercion, but Xexpr conversion will be easily<br> > accessible. A compatibility library will automatically set<br> > current-response/c appropriately.<br> > Attached is the new compatibility README.<br> > I hope this will satisfy all.<br> > Jay<br> ><br> > --<br> > Jay McCarthy <<a href="mailto:jay@cs.byu.edu">jay@cs.byu.edu</a>><br> > Assistant Professor / Brigham Young University<br> > <a href="http://faculty.cs.byu.edu/~jay" target="_blank">http://faculty.cs.byu.edu/~jay</a><br> ><br> > "The glory of God is Intelligence" - D&C 93<br> ><br> </div></div><div><div></div><div class="h5">> _________________________________________________<br> > For list-related administrative tasks:<br> > <a href="http://lists.racket-lang.org/listinfo/dev" target="_blank">http://lists.racket-lang.org/listinfo/dev</a><br> ><br> </div></div></blockquote></div><br><br clear="all"><br>-- <br>Jay McCarthy <<a href="mailto:jay@cs.byu.edu" target="_blank">jay@cs.byu.edu</a>><br>Assistant Professor / Brigham Young University<br><a href="http://faculty.cs.byu.edu/~jay" target="_blank">http://faculty.cs.byu.edu/~jay</a><br> <br>"The glory of God is Intelligence" - D&C 93<br> </div>