[Haskell-cafe] What's the problem with iota's type signature?

michael rice nowgate at yahoo.com
Wed May 27 22:33:44 EDT 2009

Still exploring monads. I don't understand why the type signature for double is OK, but not the one for iota.



--double :: (Int a) => a -> Maybe b
--double x = Just (x + x)

iota :: (Int a) => a -> [b]
iota  n = [1..n]

--usage: [3,4,5] >>= iota
--should produce [1,2,3,1,2,3,4,1,2,3,4,5]

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