[Haskell-cafe] [Q] Using Class

Andre Betz mail at andrebetz.de
Fri Feb 13 16:53:23 EST 2004


I'm a really beginner to haskell and I have a question about using classes.
I don't now really what this function does. So I will try to use it to see
what it will put out

position :: ( Enum a , Eq b ) => b -> [b] -> [a]
position x = position_snd . zip ( enumFrom $ toEnum 1 )
    where position_snd [] =  []
	  position_snd ((p,y):ys) | x == y    = p : position_snd ys
				  | otherwise =     position_snd ys

My roblem is now that I don't know how to use it.

I tried "head position 2 [1,2,3,4]" but I always get an error.

Thanks for help

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