Are varargs functions discouraged in haskell?

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This is my type:

import Numeric.AD
---
data Measurement a = Measurement !a !a

This is how I calculate a function on my type:

sqrtDiff :: Floating a => (forall a1. Floating a1 => a1 -> a1) -> a -> a -> a
sqrtDiff f a b = sqrt ((b**2) * diff f a ** 2)
newMeasurement :: Floating a => (forall a1. Floating a1 => a1 -> a1) -> Measurement a -> Measurement a
newMeasurement f (Measurement c d) = Measurement (f c) (sqrtDiff f c d)

If I have a = Measurement 3.0 0.1 and I want to compute the exponential I write: newMeasurement exp a.

If I want to compute a function with more than 1 argument I can’t. I have to write another function, here an example with a function with 2 args.

nM :: Floating a => (forall a1. Floating a1 => [a1] -> a1) -> Measurement a -> Measurement a -> Measurement a
nM f (Measurement a b) (Measurement c d) = Measurement (f [a, c]) (sqrt (((g !! 0) * b)**2 + ((g !! 1) * d)**2))
                                                where g = grad f [a, c]

If I want to compute a function with 3 args I have to write another function.

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