--   ip6addr filters parsed IPv6 Addresses against RFC 4291
--   Copyright (c) 2009-2010, Michel Boucey
--   All rights reserved.

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module CidrSuffix where

import Data.Char (isDigit)
import Data.List (groupBy)
import Data.Function (on)

isCidrSuffix :: String -> Bool
isCidrSuffix s = if all isDigit s && ((length s > 1 && head s /= '0')||(length s == 1))
				 then t >= 0 && t <= 128 else False
				 where t = read s::Int

removeCidrSuffix :: String -> String
removeCidrSuffix [] = []
removeCidrSuffix s
		  | l == 1 = s
		  | l == 3 = if g !! 1 == "/" && (isCidrSuffix $ last g) then head g else []
		  | otherwise = []
		  where
			g = groupBy ((==) `on` (=='/')) s
			l = length g