[racket] struct contract violation problem

Correct

On Wed, Oct 23, 2013 at 4:38 PM, Erik Pearson <erik at adaptations.com> wrote:
> On Wed, Oct 23, 2013 at 3:31 PM, Jay McCarthy <jay.mccarthy at gmail.com>
> wrote:
>>
>> Here are two ideas.
>>
>> 1) You simply have an old use of the original net/url. When #<url> is
>> printed, it uses the symbolic name and you can't really figure out
>> what the underlying code came from. I would do a grep to make sure
>> this is not the case.
>
>
> Would the operative places to look be the point at which the url object is
> created and then where it is used? In other words, if it is created in the
> context of net/url (i.e. a module where net/url is required) and used in a
> module with adaptnet/url required, it will look like a #<url> (when printed)
> but not be a url? according to adaptnet/url's url-structs, and where the
> object travels in between doesn't make a difference?
>
>>
>> 2) You are using namespaces somewhere and actually have two instances
>> of the same module somewhere where a value produced by copy 1 is going
>> to copy 2. This is possible with the Web server if you don't set up
>> the servlet namespace properly:
>>
>>
>> http://docs.racket-lang.org/web-server-internal/dispatch-servlets.html#(part._namespace)
>>
>> On Wed, Oct 23, 2013 at 4:25 PM, Erik Pearson <erik at adaptations.com>
>> wrote:
>> > Excuse my poor experience with contracts, this is probably an easy one.
>> >
>> > I'm using a copy of net/url and have a strange problem. The copied
>> > library
>> > is working fine in general, but this problem cropped up today:
>> >
>> > struct:exn:fail:contract:blame url-port: contract violation
>> > expected: url?
>> > given: #<url>
>> > in: the 1st argument of
>> > (-> url? (or/c #f number?))
>> > contract from:
>> > /home/epearson/work/racket/github/adaptnet/url-structs.rkt
>> > blaming: /home/epearson/work/racket/github/racqueb/httpc.rkt
>> > at: /home/epearson/work/racket/github/adaptnet/url-structs.rkt:4.28
>> >
>> > The error is thrown in my usage of url-port which is being passed a
>> > perfectly good url struct object. The file is requiring the copied
>> > url-structs. If I play with the function that is being blamed in
>> > httpc.rkt
>> > via the repl in dr racket, this specific error is not thrown. The call
>> > to
>> > (url-port url) succeeds without throwing this contract exception.
>> >
>> > From my primitive understanding, I'm flummoxed: Why is a #<url> not a
>> > url?
>> >
>> > I suspected that there may have been a leftover require of net/url
>> > confusing
>> > things, but I can't find any in my code.
>> >
>> > Using racket head from github 5.90.0.9--2013-10-20(d6610289/d)
>> >
>> > Help!
>> >
>> > Thanks,
>> > Erik.
>> >
>> >
>> >
>> > ____________________
>> >   Racket Users list:
>> >   http://lists.racket-lang.org/users
>> >
>>
>>
>>
>> --
>> Jay McCarthy <jay at cs.byu.edu>
>> Assistant Professor / Brigham Young University
>> http://faculty.cs.byu.edu/~jay
>>
>> "The glory of God is Intelligence" - D&C 93
>
>
>
>
> --
> Erik Pearson
> Adaptations
> ;; web form and function



-- 
Jay McCarthy <jay at cs.byu.edu>
Assistant Professor / Brigham Young University
http://faculty.cs.byu.edu/~jay

"The glory of God is Intelligence" - D&C 93