mima-tools/src/Mima/Util.hs
2019-11-08 18:33:08 +00:00

72 lines
1.9 KiB
Haskell

{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE TypeSynonymInstances #-}
module Mima.Util
(
-- * Formatting
ToText(..)
, HexLike(..)
, groupByTwoChars
, integralToDec
, integralToHex
) where
import qualified Data.Text as T
import Data.Word
import Data.Word.Odd
import qualified Numeric as N
{- Formatting -}
-- | A class for types that can be converted to 'T.Text'.
--
-- This class does not mean to convert elements to text in a
-- standardized way. It is just to reduce the clutter of functions
-- with names like @somethingToText@.
--
-- Only create an instance of this class when there is an obvious,
-- preferrable way of converting something to text! If there are
-- multiple "obvious" options, create no instance of this class and
-- instead name the functions individually.
class ToText a where
toText :: a -> T.Text
-- | A class for number-like types that have a decimal and a
-- hexadecimal representation.
class HexLike a where
toDec :: a -> T.Text
toHex :: a -> T.Text
toHexBytes :: a -> T.Text
toHexBytes = T.intercalate " " . groupByTwoChars . toHex
instance HexLike Word24 where
toHex = integralToHex 6
toDec = T.pack . show
instance HexLike Word20 where
toHex = integralToHex 5
toDec = T.pack . show
instance HexLike Word16 where
toHex = integralToHex 4
toDec = T.pack . show
instance HexLike Word4 where
toHex = integralToHex 1
toDec = T.pack . show
groupByTwoChars :: T.Text -> [T.Text]
groupByTwoChars = reverse . helper . T.unpack . T.reverse
where
helper (c1:c2:cs) = T.pack [c2, c1] : helper cs
helper [c] = [T.singleton c]
helper [] = []
integralToDec :: (Integral a, Show a) => Int -> a -> T.Text
integralToDec digits a = T.justifyRight digits ' ' $ T.pack $ show a
integralToHex :: (Integral a, Show a) => Int -> a -> T.Text
integralToHex digits a = T.justifyRight digits '0' $ T.pack $ N.showHex a ""