1 files changed, 32 insertions, 0 deletions

diff --git a/src/Trivstream/Options/Utils.hs b/src/Trivstream/Options/Utils.hs
new file mode 100644
index 0000000..30694d8
--- /dev/null
+++ b/src/Trivstream/Options/Utils.hs
@@ -0,0 +1,32 @@
+{-# 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]