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.htmlhttp://www.cs.chalmers.se/%7Erjmh/Papers/whyfp.html
[2]: http://www.cs.cmu.edu/~rwh/theses/okasaki.pdfhttp://www.cs.cmu.edu/%7Erwh/theses/okasaki.pdf
Best regards,
Marc
On Fri, Feb 19, 2010 at 9:07 PM, Mikhail Novikov
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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/D...), 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 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/
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