-- | Throw an index-out-of-bounds error.
errorOfBounds :: String -> Int -> Int -> a
errorOfBounds loc n i 
        =  error $ loc ++ ": Out of bounds "
                ++ "(vector length = "  ++ show n 
                ++ "; index = "         ++ show i ++ ")"
errorOfBounds :: String -> Int -> Int -> a
errorOfBounds loc n i 
        =  error $ loc ++ ": Out of bounds "
                ++ "(vector length = "  ++ show n 
                ++ "; index = "         ++ show i ++ ")"
errorOfBounds loc n i 
        =  error $ loc ++ ": Out of bounds "
                ++ "(vector length = "  ++ show n 
                ++ "; index = "         ++ show i ++ ")"