[Haskell-beginners] list monad question

[Matthias Guedemann]

Hi Daniel,

> That gives
> 
> combinations n xs = foldr f [[]] (replicate n xs)
> 
> pointfree, for extra goodness:
> 
> -- pointfree f inline
> combinations n xs = foldr ((. (. (:)) . flip map) . (>>=)) [[]] (replicate n xs)
> -- eliminate xs
> combinations n = foldr ((. (. (:)) . flip map) . (>>=)) [[]] . replicate n
> -- completely pointfree
> combinations = (foldr ((. (. (:)) . flip map) . (>>=)) [[]]  .) . replicate

thank you, looks rather strange to me but works well.

regards

-- 
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Dipl. Inf. Matthias Guedemann              / __\/ _\  /__\
Computer Systems in Engineering           / /   \ \  /_\
Otto-von-Guericke Universitaet Magdeburg / /___ _\ \//__
Tel.: 0391 / 67-19359                    \____/ \__/\__/
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