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

From: Noel Welsh (noelwelsh at gmail.com)
Date: Sun Dec 30 11:50:50 EST 2007

On Dec 29, 2007 7:35 PM, dave yrueta <dyrueta at gmail.com> 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....

I'll let Matthias or another HtDP author comment on this.

> 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.

I don't know of any works that address recursion in a general manner,
other than Godel Escher Bach.  There might be some stuff in category
theory, but it would be very maths heavy and definitely a specialist
text.  An alternative is to attack recursion as you are currently
doing -- via the medium of programming.  This may be a better route as
it makes the abstract concepts concrete, and so is a bit easier for
those of us who don't think purely in pure maths.  For a knowledge of
Scheme you can go on to programming language theory via, say, PLAI or
SICP.  This should open the door to more theoretical work.

And alternative is to tackle recursion via some application.  For
example I've recently come across this use in graphics:


I've knocked up a similar Scheme library in a day or so, and it will
be released soonish (this actually has a use for me beyond just
playing around, so it should get finished unlike many other projects
of mine).


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