more haslly please?

navigate.hs

navigate :: Direction -> Coordinate -> Maze -> Maybe Coordinate
navigate direction (x, y) m = case direction of
    N -> if isJust (getCellAt newCell m) then Just newCell else Nothing where
        newCell = (x - 1, y)
    E -> if isJust (getCellAt newCell m) then Just newCell else Nothing where
        newCell = (x, y + 1)
    S -> if isJust (getCellAt newCell m) then Just newCell else Nothing where
        newCell = (x + 1, y)
    W -> if isJust (getCellAt newCell m) then Just newCell else Nothing where
        newCell = (x, y - 1)