MutArray and Generic MutArray are using different conventions for field names

[harendra-kumar]

    MutArray
    { arrContents :: {-# UNPACK #-} !MutableByteArray
    , arrStart :: {-# UNPACK #-} !Int  -- ^ index into arrContents
    , arrEnd   :: {-# UNPACK #-} !Int    -- ^ index into arrContents
                                       -- Represents the first invalid index of
                                       -- the array.
    , arrBound :: {-# UNPACK #-} !Int    -- ^ first invalid index of arrContents.
    }

    MutArray
        { arrContents# :: MutableArray# RealWorld a
          -- ^ The internal contents of the array representing the entire array.

        , arrStart :: {-# UNPACK #-}!Int
          -- ^ The starting index of this slice.

        , arrLen :: {-# UNPACK #-}!Int
          -- ^ The length of this slice.

        , arrTrueLen :: {-# UNPACK #-}!Int
          -- ^ This is the true length of the array. Coincidentally, this also
          -- represents the first index beyond the maximum acceptable index of
          -- the array. This is specific to the array contents itself and not
          -- dependent on the slice. This value should not change and is shared
          -- across all the slices.
        }

Should change the generic array to use the same terminology as unboxed array.