* Puzzling Haskell - Richard Bird's Sudoku solution in depth
* Musical Haskell - With Ableton and the Novation Launchpad
* Spicy Haskell - The Curry-Howard Isomorphism
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Actually, it is running faster: down from 1.05s to 0.68s for the test puzzle I'm using. If I get time I'll do some comparisons to Richard Bird's solution (which I expect is still going to be faster).
0 · November 29, 2013
Thanks alan. Note that you have updated the slower version without the updates to the 'different' function that dramatically increase the amount of pruning.
By the way, I spent a bit of time this afternoon playing with the labelling function to make it label the most constrained variables first. Interestingly, I so far haven't been able to get it to run any faster by doing that.
I've uploaded David's sudoku solver to github here: https://github.com/xpika/fd-sudoku
Enjoyed the talk and discussion. Thanks Lyndon.
If anyone's interested the the constraint solver approach I mentioned, here are the articles I wrote a few years ago:http://overtond.blogspot.com.au/2008/07/pre.htmlhttp://overtond.blogspot.com.au/2008/07/haskell-sudoku-solver-using-finite.html
It doesn't use some of the optimisations that Bird used, but there's no reason why it couldn't be extended to do them. It shows that you can write much more general constraint solving systems and them use them to solve multiple problems, rather than just writing a problem-specific solution.
If anyone is interested, the vim-slides are on github: https://github.com/sordina/haskell-meetup-sudoku
Quite enjoyed the exploration of the approach to sudoko solving. A moments glance on Wikipedia lead me to this paper: http://www.kestrel.edu/home/people/meertens/publications/papers/Algorithmics.pdf which perhaps is interesting to read for people who don't have the "Algebra of Programming" book.
Just in case anyone needs to get in contact, my mobile number is[masked],
0 · November 28, 2013
Just a quick update - Andy's talk on "Spicy Haskell" (Curry-Howard) won't be running tonight as it is not ready for presentation. I thought as an alternative we could discuss the direction that we want to take the group, and possible alternatives for the format of future meetups. This should substitute in quite well, as I'm sure Andy has some views on the matter.
Also, if anyone else has something they wish to present to the group then they are more than welcome to do so.
I might be able to make it. If I do it'll be late though.
0 · November 25, 2013
Sorry I can't make it all - I was double booked to see short films with my girlfriend. Cancelling on her for Haskell would not go down well :p.
0 · November 17, 2013
No worries Andrew. See you next time then :)
0 · November 18, 2013
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