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-rw-r--r--src/Text/Pandoc/UUID.hs23
1 files changed, 12 insertions, 11 deletions
diff --git a/src/Text/Pandoc/UUID.hs b/src/Text/Pandoc/UUID.hs
index 6d6e22944..9d8cd4434 100644
--- a/src/Text/Pandoc/UUID.hs
+++ b/src/Text/Pandoc/UUID.hs
@@ -29,13 +29,12 @@ UUID generation using Version 4 (random method) described
in RFC4122. See http://tools.ietf.org/html/rfc4122
-}
-module Text.Pandoc.UUID ( UUID(..), getRandomUUID ) where
+module Text.Pandoc.UUID ( UUID(..), getRandomUUID, getUUID ) where
import Text.Printf ( printf )
-import System.Random ( randomIO )
+import System.Random ( RandomGen, randoms, getStdGen )
import Data.Word
import Data.Bits ( setBit, clearBit )
-import Control.Monad ( liftM )
data UUID = UUID Word8 Word8 Word8 Word8 Word8 Word8 Word8 Word8
Word8 Word8 Word8 Word8 Word8 Word8 Word8 Word8
@@ -64,14 +63,16 @@ instance Show UUID where
printf "%02x" o ++
printf "%02x" p
-getRandomUUID :: IO UUID
-getRandomUUID = do
- let getRN :: a -> IO Word8
- getRN _ = liftM fromIntegral (randomIO :: IO Int)
- [a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p] <- mapM getRN ([1..16] :: [Int])
+getUUID :: RandomGen g => g -> UUID
+getUUID gen =
+ let [a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p] = take 16 $ randoms gen :: [Word8]
-- set variant
- let i' = i `setBit` 7 `clearBit` 6
+ i' = i `setBit` 7 `clearBit` 6
-- set version (0100 for random)
- let g' = g `clearBit` 7 `setBit` 6 `clearBit` 5 `clearBit` 4
- return $ UUID a b c d e f g' h i' j k l m n o p
+ g' = g `clearBit` 7 `setBit` 6 `clearBit` 5 `clearBit` 4
+ in
+ UUID a b c d e f g' h i' j k l m n o p
+
+getRandomUUID :: IO UUID
+getRandomUUID = getUUID <$> getStdGen