[racket] Strange contracts in the tutorial

I've updated the tutorial to say "doesn't return" rather than "doesn't"

Jay

2011/6/13 Rodolfo Carvalho <rhcarvalho at gmail.com>

> Ok, now I get what it means.
>
> Still, it feels confusing in the way that it's written.
>
> []'s
>
> Rodolfo Carvalho
>
>
>
> On Mon, Jun 13, 2011 at 20:55, Matthias Felleisen <matthias at ccs.neu.edu>wrote:
>
>>
>> The author tried to say it doesn't return.
>>
>> In a Racket-like context, the author could have specified
>>
>>  ;; render-blog-page : request -> ∅
>>
>> Since there are no elements in the emptyset, this specification says the
>> same thing mathematically, using Racket's `types as sets' standard form of
>> loose reasoning. I doubt it would have been more easily understood.
>>
>> An MLer could have said α again because it is impossible to return
>> something of this type if the function's domain isn't specified as such.
>> Would this help?
>>
>> -- Matthias
>>
>>
>>
>>
>> On Jun 13, 2011, at 5:13 PM, Rodolfo Carvalho wrote:
>>
>> Hi,
>>
>> I'm reading the User Guide: Continue<http://docs.racket-lang.org/continue/> and
>> I'm puzzled with some contracts that reads:
>>
>>   ; render-blog-page: request -> doesn't ; Produces an doesn't page of
>>> the content of the ; BLOG.
>>
>>
>>
>> Is it correct? What does it mean that it "produces an doesn't"?
>>
>> []'s
>>
>> Rodolfo Carvalho
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>
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-- 
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
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