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{-# LANGUAGE TemplateHaskell #-}
module WWW.Colors.Hex
( HexColor
) where
import Data.Colour
import Digrams.Attributes
import Language.Haskell.TH.Quote
newtype HexColor = HexColor ByteString
deriving (Eq, Generic, Ord)
instance Bounded HexColor where
maxBound = HexColor "\255\255\255"
minBound = HexColor "\NUL\NUL\NUL"
instance Color HexColor where
hex :: QuasiQuoter
hex = QuasiQuoter
{ quoteExp = parseit
, quotePat = failure "quotePat"
, quoteType = failure "quoteType"
, quoteDec = failure "quoteDec"
} where
failure s = const $ fail $ "No " <> s <> " defined for the hexcolor quasiquoter."
parseit s = case undefined of
Nothing -> fail $ "Can't understand " <> s <> " as a valid hex color."
Just h -> h `seq` [|h|]
|
