blob: 30694d8d0696a02dc3de985ad0074b2cb6dd2b18 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
|
{-# LANGUAGE StandaloneDeriving #-}
module Trivstream.Options.Utils
( rCI
) where
import Options.Applicative
import Data.Char
import Data.Maybe
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]
|
