I do not use the interface from net collection, Module "ssl-url" was provided by Jens, (call/input-url (opt->* (url?                             (opt-> (url?) ((listof string?)) input-port?)                             (input-port? . -> . any))                            ((listof string?))                            any)) BTW, I have tried several times to upgrade to current SVN, but the redex code (3.28) I wrote on version 371 could not run anymore on 3.99 or later. So I prefer staying on 371.2 <div class="gmail_quote">On Dec 17, 2007 10:34 PM, Robby Findler <<a href="mailto:robby@cs.uchicago.edu">robby@cs.uchicago.edu</a>> wrote: <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> Oh, one other point. It was pointed out earlier that the function does not actually need that strict of a contract and I believe the contract has been relaxed in SVN. Robby <div> <div></div><div class="Wj3C7c"> On Dec 17, 2007 8:22 AM,  <<a href="mailto:yug@ios.ac.cn">yug@ios.ac.cn</a>> wrote: > Thanks!! Robby > > The right def is > > > (call/input-url (string->url " <a href="https://210.77.16.29/php/user_login.php" target="_blank">https://210.77.16.29/php/user_login.php</a>") >                   (case-lambda >                      [(url) (post-impure-port url data rhead)] >                     [(url rhead) (post-impure-port url data rhead)]) >                   display-pure-port >                   ) > > > >  On Dec 17, 2007 10:15 PM, Robby Findler < <a href="mailto:robby@cs.uchicago.edu">robby@cs.uchicago.edu</a>> wrote: > > The contract is insisting that you provide a function that accepts > > *both* one argument and two arguments. > > > > Robby > > > > > > > > > > On Dec 17, 2007 8:13 AM,  < <a href="mailto:yug@ios.ac.cn">yug@ios.ac.cn</a>> wrote: > > > Hi, > > > > > >   I'm fresh to contracts. Here is my problem: > > > > > > I just want to pass the contracts check on the following definition: > > > > > >  (define test (lambda (url) > > >                  (post-impure-port url data rhead))) > > > > > > (provide/contract (test (-> url? input-port?))) > > > > > > (call/input-url (string->url " <a href="https://210.77.16.29/php/user_login.php" target="_blank"> https://210.77.16.29/php/user_login.php</a>") > test > > > display-pure-port) > > > > > > or even more simplified: > > > > > > (call/input-url (string->url " <a href="https://210.77.16.29/php/user_login.php" target="_blank">https://210.77.16.29/php/user_login.php</a>") > > >                    (lambda (url) > > >                        (post-impure-port url data rhead))) > > >                   display-pure-port) > > > > > > Every time, I get: > > >   (case-> > > >     (-> > > >      url? > > >      (case-> > > >        (-> url? input-port?) > > >        (-> url? (listof string?) input-port?)) > > >      (-> input-port? any) > > >      any) > > >     (-> > > >      url? > > >      (case-> > > >        (-> url? input-port?) > > >        (-> url? (listof string?) input-port?)) > > >      (-> input-port? any) > > >      (listof string?) > > >      any)) > > > on call/input-url; expected a procedure that accepts 2 arguments, given: > > > #<procedure:test> > > > > > > If I change the definition to > > > (call/input-url (string->url " <a href="https://210.77.16.29/php/user_login.php" target="_blank">https://210.77.16.29/php/user_login.php</a>") > > >                   (lambda (url rhead) > > >                     (post-impure-port url data rhead) > > >                     ) > > >                   display-pure-port > > >                   ) > > > . . ssl-url.scm:40:4: /home/yug/ssl-url.scm:40:4: top-level broke the > > > contract > > >   (case-> > > >     (-> > > >      url? > > >      (case-> > > >        (-> url? input-port?) > > >        (-> url? (listof string?) input-port?)) > > >      (-> input-port? any) > > >      any) > > >     (-> > > >      url? > > >      (case-> > > >        (-> url? input-port?) > > >        (-> url? (listof string?) input-port?)) > > >      (-> input-port? any) > > >      (listof string?) > > >      any)) > > > on call/input-url; expected a procedure that accepts 1 arguments, given: > > > #<procedure> > > > > > > > > > > How can I define my function? > > > > > > Thanks > > > > > > -- > > > Gang > > > _________________________________________________ > > >   For list-related administrative tasks: > > >   <a href="http://list.cs.brown.edu/mailman/listinfo/plt-scheme" target="_blank">http://list.cs.brown.edu/mailman/listinfo/plt-scheme</a> > > > > > > > > _________________________________________________ > >  For list-related administrative tasks: > >  <a href="http://list.cs.brown.edu/mailman/listinfo/plt-scheme" target="_blank"> http://list.cs.brown.edu/mailman/listinfo/plt-scheme</a> > > > > > > -- > Gang _________________________________________________  For list-related administrative tasks:  <a href="http://list.cs.brown.edu/mailman/listinfo/plt-scheme" target="_blank"> http://list.cs.brown.edu/mailman/listinfo/plt-scheme</a> </div></div></blockquote></div> -- Gang