[racket] class variables in racket

From: Grant Rettke (grettke at acm.org)
Date: Thu Jan 19 17:56:57 EST 2012

In Java for example which doesn't have modules you would create a
class whose sole purpose in life was to hold those constants. Did you
guys make that choice consciously?

On Thu, Jan 19, 2012 at 3:58 PM, Robby Findler
<robby at eecs.northwestern.edu> wrote:
> But is this style of OOP thinking because of a weakness in the design
> of the OOP that Racket (as it famously inherits from Scheme (ala
> Clinger's intro to the RnRS reports)) avoids?
>
> Robby
>
> On Thu, Jan 19, 2012 at 1:41 PM, Christian Wagenknecht
> <c.wagenknecht at hs-zigr.de> wrote:
>> I expected to find some special-form, like 'class-variable' or something
>> like that.
>>
>> For pedagogical reasons I'd prefer to implement two syntactically different
>> programs representing the oop thinking style quite obvious: the first one
>> makes absolutely no use of the bindings provided by the 'class' library that
>> comes with Racket whereas the second one is mainly limited to take them. The
>> first one helps the students to understand lots behind the scene of how oop
>> works and why. The second one abstracts of that and really allows for oo
>> programming.
>>
>> What I mean is that the terms describing the basic concepts of object
>> oriented programming should be mapped to related code. Using 'let' to get
>> the right variable scope causes to mix both levels of thinking /
>> abstraction. Thats exactly what I like to avoid.
>>
>> Am 19.01.2012 18:09, schrieb Matthias Felleisen:
>>
>>>
>>> On Jan 19, 2012, at 11:57 AM, Christian Wagenknecht wrote:
>>>
>>>> How class variables/methods (instead of instance variables/methods) can
>>>> be implemented be means of Racket's class definition expressions? An
>>>> unsatisfying way I found is by using a let expression enclosing the whole
>>>> definition of the class.
>>>
>>>
>>> What's unsatisfying about it?
>>
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