[Haskell-beginners] Translating imperative algorithms to Haskell

[Mikhail Novikov]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hello!

Thanks, I'll take a look. I was going to buy Okasaki's book for a very long time, probably I should finally do it :)

Best regards, Mikhail

On 02/19/2010 11:07 PM, Marc Dominik Migge wrote:
> Hi,
> 
> I recommend you read John Hughe's article "Why Functional Programming
> Matters"[1]. As one of his examples he implements alpha-beta-pruning. I'm
> not really a Haskell expert, but I think the main difference will be in the
> kind of data structures you use to implement the algorithms. Many people
> have recommended Chris Okasaki's PhD thesis [2] to me for an in-depth
> treatment of the topic.
> 
> [1]: http://www.cs.chalmers.se/~rjmh/Papers/whyfp.html
> [2]: http://www.cs.cmu.edu/~rwh/theses/okasaki.pdf
> 
> Best regards,
> Marc
> 
> 
> On Fri, Feb 19, 2010 at 9:07 PM, Mikhail Novikov <freiksenet at gmail.com>wrote:
> 
> Hello!
> 
> Four days ago I decided to try to learn Haskell by participating in Google
> AI Challenge (http://csclub.uwaterloo.ca/contest/). I went with LYAH and
> Real-World Haskell and I had no problems with functional core of Haskell, as
> I have lispy background. The problems begun when I tried to move my code to
> use different kind of decision algorithms, like negascout or flood fill.
> 
> I have found a ready made solution for negascout (
> http://hackage.haskell.org/packages/archive/game-tree/0.1.0.0/doc/html/src/Data-Tree-Game_tree-Negascout.html),
> but I was quite shocked by it's complexity, especially considering the
> relative easy of imperative algorithm.(
> http://en.wikipedia.org/wiki/Negascout). IMHO it is just TOO extremely
> complex and hard to read :/
> 
> In flood fill situation is similar - I need to track all the colored
> squares among 4 lines of recursion and I couldn't find a reasonable way to
> do it without going to infinite recursion or having lots of duplicates.
> 
> So basically, I wonder if there is some generic way to transfer imperative
> algorithms with local state to functional style without making them overly
> complex.
> 
> Thanks a lot, Mikhail
_______________________________________________
Beginners mailing list
Beginners at haskell.org
http://www.haskell.org/mailman/listinfo/beginners
>>

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.10 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/

iEYEARECAAYFAkt+/6YACgkQPHyh4sfuKrkrdgCfaH4/z1RrQX33dtoO1QXWQshl
LBUAn18H9/MdMjbGzeTJZ9+bxVYs5tfJ
=9ZhZ
-----END PGP SIGNATURE-----