[Haskell-beginners] Type of function or type of the output of function?

[Trung Quang Nguyen]

Hi there,

I have a quickSort implementation, then I try to use :t in ghci to inspect
what type I receive. I got this.

*Main> :t quickSort "Hello the world"
quickSort "Hello the world" :: [Char]
*Main> :t quickSort [3,2, 1,-10]
quickSort [3,2, 1,-10] :: (Num a, Ord a) => [a]

The first one looks like :t return type of output of quickSort [Char]

The second one looks like :t return the type of function (Num a, Ord a) =>
[a]

Anybody know why this happens? When we will receive type of output, or type
of function? And why (Num a, Ord a) => [a], even quickSort doesn't have
explicit type, so this type comes from input type and type of function is
defined in runtime?

Thanks a lot!

Cheers,
Trung
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