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{-# LANGUAGE StandaloneDeriving #-}
module Trivstream.Options.Utils
( rCI
) where
import Options.Applicative
import Data.Char
import Data.Maybe
import Text.Read (readMaybe)
import Network.Socket
deriving instance Enum Family
deriving instance Bounded Family
rCI :: (Show a, Read a) => ReadM a
rCI = eitherReader rRep'
where
rRep' str = case mapMaybe readMaybe $ cases str of
[] -> Left $ "Could not parse `" ++ str ++ "'"
[x] -> Right x
xs -> Left $ "Ambiguous parse for `" ++ str ++ "': " ++ show xs
cases [] = [[]]
cases (c:cs) = [(c':cs') | c' <- [toLower c, c, toUpper c], cs' <- cases cs]
rFamily :: ReadM Family
rFamily = undefined
where
families = filter isSupportedFamily [minBound..maxBound]
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