I am very thankful for the advices of all contributors which help me to rethink
my goals. There are only some quite simple rules the students have to apply
when defining classes, for example: employ an internal definition (represented
by 'define' / 'define-values') to implement a (private) instance variable; put
the variable into an enclosing 'let' in case of a class variable.
Nevertheless there are obviously also other people looking for appropriate syntactical representations of the OOP terms
(mainly for teaching purposes as I guess): Right now I found
http://www.google.de/url?sa=t&rct=j&q=oop%20extensions%20of%20scheme&source=web&cd=4&ved=0CEgQFjAD&url=http%3A%2F%2Finst.eecs.berkeley.edu%2F~cs47a%2Foop.pdf&ei=yVIZT9CECYKf-wb5p6i4Cg&usg=AFQjCNGuaNDt293VtMmDVT4O_dR5rw9ouw&sig2=X47LnwLEdhMy-oS2QcTy2w&cad=rja.
Within the text you will find the forms class-vars, instance-vars, ...
Thanks again,
Christian
Am 20.01.2012 00:00, schrieb Matthias Felleisen:
Of course.
On Jan 19, 2012, at 5:56 PM, Grant Rettke wrote:
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
<ro...@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.wagenkne...@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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