$> diff QuicksortFast.hs Quicksort.hs
5,6c5
< import Control.Monad (foldM)
< import Control.Monad.ST (ST)
---
> import Control.Monad (foldM, liftM)
12c11
< partition ∷ Ord ε ⇒ STArray s Int ε → (Int, Int) → ST s Int
---
> partition ∷ (Enum γ, Num γ, Ix γ, Ord ε, MArray α ε μ) ⇒ α γ ε → (γ, γ) → μ γ
33c32
< quicksort' ∷ Ord ε ⇒ STArray s Int ε → (Int, Int) → ST s ()
---
> quicksort' ∷ (Enum γ, Num γ, Ix γ, Ord ε, MArray α ε μ) ⇒ α γ ε → (γ, γ) → μ ()