I am learning haskell and am a little confused how the function application operator $ curry's.

According to GHC the type of $ is 

*Main>:t ($)
($) :: (a->b) -> a -> b

But I can type the following code

*Main>map ($ 2) [(*2), (+2), (/2)]
[4.0,4.0,1.0]

According to the signature of $ though I would assume I would need to use the flip function because the first parameter to $ is (a->b).

For example, I can't do the following

curry_test :: Integer -> String -> String
curry_test x y = (show x) ++ " " ++ y
*Main> let x = curry_test "123"
    Couldn't match expected type `Integer' with actual type `[Char]'
In the first argument of `curry_test', namely `"123"'
In the expression: curry_test "123"
In an equation for `x': x = curry_test "123"

But I can do

let x = curry_test 2
haskell currying
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