[Haskell-beginners] count function
felipe.lessa at gmail.com
Sun Oct 18 13:43:00 EDT 2009
On Sun, Oct 18, 2009 at 06:51:41PM +0200, Daniel Fischer wrote:
> fileLines str = readFile str >>= return . length . lines
This kind of construction requires a Monad, which is a lot of power.
> fmap (length . lines) (readFile str)
On the other hand, this only requires a Functor. Yes, in this
particular case the type is going to be IO anyway, but 'fmap'
should be used instead of '>>= return .'.
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