Compatibility with older versions of base and bytestring

2 files changed, 19 insertions, 2 deletions

diff --git a/haddock-library/src/Documentation/Haddock/Parser.hs b/haddock-library/src/Documentation/Haddock/Parser.hs
index 3d146d33..f0597462 100644
--- a/haddock-library/src/Documentation/Haddock/Parser.hs
+++ b/haddock-library/src/Documentation/Haddock/Parser.hs
@@ -437,7 +437,7 @@ autoUrl = mkLink <$> url
   where
     url = mappend <$> ("http://" <|> "https://" <|> "ftp://") <*> takeWhile1 (not . isSpace)
     mkLink :: BS.ByteString -> DocH mod a
-    mkLink s = case BS.unsnoc s of
+    mkLink s = case unsnoc s of
       Just (xs, x) | x `elem` ",.!?" -> DocHyperlink (Hyperlink (decodeUtf8 xs) Nothing) <> DocString [x]
       _ -> DocHyperlink (Hyperlink (decodeUtf8 s) Nothing)
 
diff --git a/haddock-library/src/Documentation/Haddock/Parser/Util.hs b/haddock-library/src/Documentation/Haddock/Parser/Util.hs
index 25dba2d5..ef2af140 100644
--- a/haddock-library/src/Documentation/Haddock/Parser/Util.hs
+++ b/haddock-library/src/Documentation/Haddock/Parser/Util.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 -- |
 -- Module      :  Documentation.Haddock.Parser.Util
 -- Copyright   :  (c) Mateusz Kowalczyk 2013-2014,
@@ -9,7 +10,14 @@
 -- Portability :  portable
 --
 -- Various utility functions used by the parser.
-module Documentation.Haddock.Parser.Util where
+module Documentation.Haddock.Parser.Util (
+  unsnoc
+, strip
+, takeUntil
+, makeLabeled
+, takeHorizontalSpace
+, skipHorizontalSpace
+) where
 
 import           Control.Applicative
 import           Control.Monad (mfilter)
@@ -18,6 +26,15 @@ import           Data.ByteString.Char8 (ByteString)
 import qualified Data.ByteString.Char8 as BS
 import           Prelude hiding (takeWhile)
 
+#if MIN_VERSION_bytestring(0,10,2)
+import           Data.ByteString.Char8 (unsnoc)
+#else
+unsnoc :: ByteString -> Maybe (ByteString, Char)
+unsnoc bs
+  | BS.null bs = Nothing
+  | otherwise = Just (BS.init bs, BS.last bs)
+#endif
+
 -- | Remove all leading and trailing whitespace
 strip :: String -> String
 strip = (\f -> f . f) $ dropWhile isSpace . reverse