And the one liner:
(rand 1 10) >>= return . (\v -> take v [1..10])
On Wed, Sep 24, 2008 at 5:10 PM, Lev Walkin
forgot return, of course:
myTake :: IO [Int] myTake = do n <- rand 1 10 return $ take n [1..10]
Lev Walkin wrote:
Iain Barnett wrote:
Hi,
I have a function, that produces a random number between two given numbers
rand :: Int -> Int -> IO Int rand low high = getStdRandom (randomR (low,high))
(Naively) I'd like to write something like
take (rand 1 10 ) [1..10]
and see [1,2,3,4] ... or anything but nasty type-error messages.
myTake :: IO [Int] myTake = do n <- rand 1 10 take n [1..10]
or
myTake = rand 1 10 >>= \n -> take n [1..10]
or
myTake = rand 1 10 >>= flip take [1..10]
I'm reading about 6 tutorials on monads simultaneously but still can't
crack this simple task, and won't pain you with all the permutations of code I've already tried. It's a lot, and it ain't pretty.
Would anyone be able to break away from C/C++ vs Haskell to help? Just a point in the right direction or a good doc to read, anything that helps will be much appreciated.
Monad enlightenment happens after 7'th monad tutorial. Verified by me and a few of my friends.
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-- /jve