3 files changed, 9 insertions, 12 deletions
diff --git a/src/Text/Pandoc/Readers/Docx.hs b/src/Text/Pandoc/Readers/Docx.hs
index 86ce62ced..be486c83f 100644
--- a/src/Text/Pandoc/Readers/Docx.hs
+++ b/src/Text/Pandoc/Readers/Docx.hs
@@ -86,7 +86,7 @@ import Text.Pandoc.Readers.Docx.TexChar
 import Text.Pandoc.Shared
 import Text.Pandoc.MediaBag (insertMedia, MediaBag)
 import Data.Maybe (mapMaybe, fromMaybe)
-import Data.List (delete, isPrefixOf, (\\), intercalate, intersect)
+import Data.List (delete, stripPrefix, (\\), intercalate, intersect)
 import Data.Monoid
 import qualified Data.ByteString.Lazy as B
 import qualified Data.Map as M
@@ -455,8 +455,8 @@ oMathElemToTexString (LowerLimit base limElems) = do
     --  we want to make sure to replace the `\rightarrow` with `\to`
   let arrowToTo :: String -> String
       arrowToTo "" = ""
-      arrowToTo s | "\\rightarrow" `isPrefixOf` s =
-        "\\to" ++ (arrowToTo $ drop (length "\\rightarrow") s)
+      arrowToTo s | Just s' <- stripPrefix "\\rightarrow" s =
+        "\\to" ++ arrowToTo s'
       arrowToTo (c:cs) = c : arrowToTo cs
       lim' = arrowToTo lim
   return $ case baseString of
@@ -470,8 +470,8 @@ oMathElemToTexString (UpperLimit base limElems) = do
     --  we want to make sure to replace the `\rightarrow` with `\to`
   let arrowToTo :: String -> String
       arrowToTo "" = ""
-      arrowToTo s | "\\rightarrow" `isPrefixOf` s =
-        "\\to" ++ (arrowToTo $ drop (length "\\rightarrow") s)
+      arrowToTo s | Just s' <- stripPrefix "\\rightarrow" s =
+        "\\to" ++ arrowToTo s'
       arrowToTo (c:cs) = c : arrowToTo cs
       lim' = arrowToTo lim
   return $ case baseString of
@@ -698,8 +698,8 @@ ilToCode Space = " "
 ilToCode _     = ""
 
 isHeaderClass :: String -> Maybe Int
-isHeaderClass s | "Heading" `isPrefixOf` s =
-  case reads (drop (length "Heading") s) :: [(Int, String)] of
+isHeaderClass s | Just s' <- stripPrefix "Heading" s =
+  case reads s' :: [(Int, String)] of
     [] -> Nothing
     ((n, "") : []) -> Just n
     _       -> Nothing
diff --git a/src/Text/Pandoc/Readers/Org.hs b/src/Text/Pandoc/Readers/Org.hs
index 065f5a046..e1c29d1e8 100644
--- a/src/Text/Pandoc/Readers/Org.hs
+++ b/src/Text/Pandoc/Readers/Org.hs
@@ -274,7 +274,7 @@ optionalAttributes parser = try $
 parseBlockAttributes :: OrgParser ()
 parseBlockAttributes = do
   attrs <- many attribute
-  () <$ mapM (uncurry parseAndAddAttribute) attrs
+  mapM_ (uncurry parseAndAddAttribute) attrs
  where
    attribute :: OrgParser (String, String)
    attribute = try $ do
diff --git a/src/Text/Pandoc/Readers/RST.hs b/src/Text/Pandoc/Readers/RST.hs
index b7bc83e86..e5eccb116 100644
--- a/src/Text/Pandoc/Readers/RST.hs
+++ b/src/Text/Pandoc/Readers/RST.hs
@@ -47,7 +47,7 @@ import Text.Pandoc.Builder (Inlines, Blocks, trimInlines, (<>))
 import qualified Text.Pandoc.Builder as B
 import Data.Monoid (mconcat, mempty)
 import Data.Sequence (viewr, ViewR(..))
-import Data.Char (toLower)
+import Data.Char (toLower, isHexDigit)
 
 -- | Parse reStructuredText string and return Pandoc document.
 readRST :: ReaderOptions -- ^ Reader options
@@ -656,9 +656,6 @@ extractUnicodeChar s = maybe Nothing (\c -> Just (c,rest)) mbc
   where (ds,rest) = span isHexDigit s
         mbc = safeRead ('\'':'\\':'x':ds ++ "'")
 
-isHexDigit :: Char -> Bool
-isHexDigit c = c `elem` "0123456789ABCDEFabcdef"
-
 extractCaption :: RSTParser (Inlines, Blocks)
 extractCaption = do
   capt <- trimInlines . mconcat <$> many inline