Re: [Haskell-cafe] List of functions

On 8/31/05, Krasimir Angelov wrote:

2005/8/31, Sebastian Sylvan :

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On 8/31/05, Dinh Tien Tuan Anh wrote:

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Something like (untested)...

xs <- zipWith ($) forkIO (map (\f -> f x y) funs) tids <- sequence xs

what does "zipWith ($)" do ?

$ is function application, so zipWith ($) will "zip" a list of functions with a list of arguments, by applying the functions to the arguments pair-wise, producing a list of results.

But forkIO is function not a list of functions. The above example is incorrect. I think it should be:

tids <- sequence [forkIO (f x y) | f <- funs]

The following corrects the zipWith example: xs <- zipWith ($) (repeat forkIO) (map (\f -> f x y) funs) tids <- sequence xs -- "50% of marriages today end in divorce, the other 50% end in death. Which would you rather have?"