[racket-dev] Removing Xexpr preference from Web Server

On Sun, Dec 5, 2010 at 8:00 AM, Jay McCarthy <jay.mccarthy at gmail.com> wrote:
> All dynamic/c does is apply three contracts in a particular order where one
> is dynamic.
> 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)
> The default value of current-response/c is a projection (any/c)
> 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"
> 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?

It also slightly bothers me that you use it with the other contracts,
even though it isn't a contract.

(In case it wasn't clear, this is a coding guidelines issue, fwiw.)

I don't care what else you call it. Coercion seems like a good word,
if you want a suggestion.

Robby

> Jay
>
> On Sun, Dec 5, 2010 at 6:46 AM, Robby Findler <robby at eecs.northwestern.edu>
> wrote:
>>
>> You've made a contract that isn't a projection, but does a coercion?
>>
>> I'd be happier if you instead made your own separate wrappers and
>> didn't use "/c" and didn't call this a contract.
>>
>> Robby
>>
>> On Sun, Dec 5, 2010 at 12:29 AM, Jay McCarthy <jay.mccarthy at gmail.com>
>> wrote:
>> > Giving special consideration to Eli and YC's perspectives, I've come up
>> > with
>> > the following way out of this problem.
>> > I found a way to provide a global hook that is tasteful to me. I've
>> > created
>> > "dynamic/c". Here's a little example:
>> > Examples:
>> >   (define p (make-parameter any/c))
>> >   (define c (dynamic/c string? p number?))
>> >   > (contract c "123" 'pos 'neg)
>> >   pos broke the contract
>> >     (dynamic
>> >      string?
>> >      #<procedure:parameter-procedure>
>> >      number?)
>> >    on eval:5:0; expected <number?>, given: "123"
>> >   > (p (coerce/c string->number))
>> >   > (contract c "123" 'pos 'neg)
>> >   123
>> >   > (contract c "123a" 'pos 'neg)
>> >   pos broke the contract
>> >     (dynamic
>> >      string?
>> >      #<procedure:parameter-procedure>
>> >      number?)
>> >    on eval:8:0; Coercion failed
>> > The Web Server will define response/c as (dynamic/c any/c
>> > current-response/c
>> > response?) and provide the current-response/c parameter for
>> > customization.
>> > The default will be no coercion, but Xexpr conversion will be easily
>> > accessible. A compatibility library will automatically set
>> > current-response/c appropriately.
>> > Attached is the new compatibility README.
>> > I hope this will satisfy all.
>> > Jay
>> >
>> > --
>> > 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
>> >
>> > _________________________________________________
>> >  For list-related administrative tasks:
>> >  http://lists.racket-lang.org/listinfo/dev
>> >
>
>
>
> --
> 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
>