[Haskell-beginners] Calling "zipWith" using "^" function.

[Venu Chakravorty]

Hello there,
This is just some toy program I was trying. I fail to understand why this works:



=============================
Prelude> zipWith (\ x y -> ((x ^ y) / (product [1..x]))) [1..3] [2,2,2]

[1.0,2.0,1.5]
=============================


and this does not:


=============================
Prelude> zipWith (\ x y -> ((y ^ x) / (product [1..x]))) [1..3] [2,2,2]


<interactive>:1:19:
    Ambiguous type variable `a' in the constraints:
      `Fractional a' arising from a use of `/' at <interactive>:1:19-44
      `Integral a' arising from a use of `^' at <interactive>:1:20-24
    Probable fix: add a type signature that fixes these type variable(s)
============================
Note that the "^" function has "x" and "y" flipped.


:t (^) says:
============================

(^) :: (Num a, Integral b) => a -> b -> a

============================


Could somebody please throw some light?



Thanks.

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