{-# LANGUAGE DeriveFoldable #-}
module Util (module Util, toList) where

import Data.Foldable (toList)
import Data.Word (Word8)


data Snoc a = SnocNil | Snoc (Snoc a) a
  deriving (Show, Foldable)

-- | Time-of-day, in unspecified time zone
data YMDHMS = YMDHMS {-# UNPACK #-} !YMD
                     {-# UNPACK #-} !HMS
  deriving (Show)

-- | Calendar day
data YMD = YMD {-# UNPACK #-} !Int
               {-# UNPACK #-} !Word8  -- ^ 1-based
               {-# UNPACK #-} !Word8
  deriving (Show)

-- | Time-of-day in seconds, in unspecified time zone
data HMS = HMS {-# UNPACK #-} !Word8
               {-# UNPACK #-} !Word8
               {-# UNPACK #-} !Word8
  deriving (Show)

pad :: Show a => Char -> Int -> a -> String
pad c w val =
  let s = show val
  in replicate (w - length s) c ++ s