On 21/10/06, Tomasz Zielonka
Do you also have this experience with Haskell?: when you feel that some code is not ideal, almost always it can be improved.
One of the recurring features of the #haskell IRC conversations is something called 'Algorithm Golf' (which is a misnomer and should really be 'Algorithm Tennis'): one person will request an algorithm and anyone interested sets about building their own. The results are then shared using lambdabot's Haskell evaluation feature and collaboratively improved. Aside from leading to efficient and natural-looking solutions to people's problems, the rounds are often pedagogical and great fun! Silly spin-offs are also common, leading to such wiki pages as http://haskell.org/haskellwiki/Compose. That particular example was mostly my doing and answers the question 'Can you build a function compose :: [a -> a] -> a -> a, such that a value will be fed into the top of the list and we'll get a result out of the bottom?'. Of course, the sane solution is foldl (flip (.)) id, but after noticing that the State monad permits a particularly elegant solution, execState . mapM modify, the task evolved into 'In how many other monads can we write this function?' The examples get more and more silly until we reach Cont when things disappear off the proverbial horizon into the land of 'How on Earth did Cale ever think of that?'. I'd recommend hanging out in the channel to anyone. :) -- -David House, dmhouse@gmail.com