[plt-scheme] Re: Novice needs help writing function

From: Matthias Felleisen (matthias at ccs.neu.edu)
Date: Sun Dec 30 10:47:23 EST 2007

Perhaps I misunderstood your question but this is a perfectly fine  
solution.

On Dec 29, 2007, at 2:35 PM, dave yrueta wrote:

> Thanks for all the input everyone.
>
> I took N's advice, revisited the problem by stepping through the
> design recipe, and came up with the following core and auxiliary
> functions which cheat a bit....
>
> (define (apply-n1 face count)
>    (cond
>       [(zero? count) (draw-losh face)]
>       [else (apply-n3(move-picture 1 face)(sub1 count))]))
>
> (define (apply-n count)
>   (apply-n3 FACE count))
>
> Does this solution satisfy the pedagogical function of the problem?
>
> Also, cheers to M. for a wonderful book!  For awhile I've had an
> interest in computer programming, but career obligations have
> relegated it to a hobby.  For someone like me, who has never taken a
> CS course and is not very good at math, the text is a godsend!
>
> Having come across the concept of recursion in general interest texts
> like Godel Escher Bach and Godel's Proof, thanks to HTDP, I finally
> feel as though I've gained some basic understanding of how it works.
> I'm not sure if this is the appropriate forum, but I was wondering if
> anyone could recommend a good introductory text on recursion
> comprehensible to a non-specialist like myself.  I think it's a
> fascinating topic, and I'd love to learn more about it.


HtDP :-)

What are you looking for and may I forward the paragraphs (minus the  
praise) to the PLT mailing list for educators. -- Matthias








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> On Dec 29, 7:14 am, Matthias Felleisen <matth... at ccs.neu.edu> wrote:
>> In this particular case, the problem is on my side. Working
>> with draw.ss just doesn't fit with the natural development of
>> the design recipe. I should have taken this symptom more seriously
>> when I wrote this extended exercise. -- Matthias
>>
>> On Dec 29, 2007, at 8:42 AM, Noel Welsh wrote:
>>
>>> The design recipes are a (if not the) core part of HtDP.  HtDP is  
>>> the
>>> only book I know that takes designing programs from a dark and
>>> mysterious art to a systematic process anyone can apply.  This is a
>>> really really powerful idea.  So, if you haven't worked through the
>>> design recipe, do so.  If you have, then you might say what
>>> difficulties you are having applying the recipe.
>>
>>> N.
>>> _________________________________________________
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>>>  http://list.cs.brown.edu/mailman/listinfo/plt-scheme
>>
>> _________________________________________________
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> _________________________________________________
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