An ambiguous variable of type `a0 ', arising from the use of` it'

Question

I have the following function returning pairs of factors for a given number

factorPairs:: (RealFrac a, Floating a, Integral a) => a -> [(a, a)]
factorPairs n = map(\x -> (x, div n x)) [y | y <- [1..(ceiling $ sqrt n)], n `rem` y == 0]

When I call a function in ghci factorPairs 18, I get a runtime error

   * Ambiguous type variable `a0' arising from a use of `it'
      prevents the constraint `(Floating a0)' from being solved.
      Probable fix: use a type annotation to specify what `a0' should be.
      These potential instances exist:
        instance Floating Double -- Defined in `GHC.Float'
        instance Floating Float -- Defined in `GHC.Float'
    * In the first argument of `print', namely `it'
      In a stmt of an interactive GHCi command: print it

I can hard code a function in ghci

map(\x -> (x, div 18 x)) [y | y <- [1..(ceiling $ sqrt 18)], 18 `rem` y == 0]  and I have no problems, but I can not understand why my function fails. I believe ghci is trying to tell me that it cannot figure out what type to call print, but I'm struggling to find a solution.

Answer 1

, Haskell. map(\x -> (x, div 18 x)) [y | y <- [1..(ceiling $ sqrt 18)], 18 `rem` y == 0] ghci, 18, sqrt, Double, - Integer s.

,

factorPairs:: (RealFrac a, Floating a, Integral a) => a -> [(a, a)]
factorPairs n = map(\x -> (x, div n x)) [y | y <- [1..(ceiling $ sqrt n)], n `rem` y == 0]

n . , ( , , ), , GHC " ", . , fromIntegral :

factorPairs:: Integral a => a -> [(a, a)]
factorPairs n = map(\x -> (x, div n x)) [y | y <- [1..(ceiling $ sqrt $ fromIntegral n)], n `rem` y == 0]

Answer 2

- sqrt. Haskell , [1..n], , .

factorPairs :: Integral a => a -> [(a, a)]
factorPairs n = takeWhile (uncurry (>=)) [ (n `div` d, d) | d <- [1..n], n `mod` d == 0]

uncurry (>=) - \(q, d) -> q >= d.

, divMod, .

factorPairs n = takeWhile (uncurry (>=)) $ do
                d <- [1..n]
                let (q, r) = n `divMod` d
                guard $ r == 0
                return (q, d)