1 files changed, 6 insertions, 10 deletions

diff --git a/bbcode/src/Text/BBCode.hs b/bbcode/src/Text/BBCode.hs
index 75fa219..2e3a753 100644
--- a/bbcode/src/Text/BBCode.hs
+++ b/bbcode/src/Text/BBCode.hs
@@ -19,7 +19,7 @@ import GHC.Generics (Generic)
 import Control.Exception (Exception)
 import Data.Typeable (Typeable)
 
-import Control.Monad (unless, join)
+import Control.Monad (unless, join, foldM)
 import Data.Function (on)
 import Control.Applicative
 
@@ -87,16 +87,12 @@ rose :: [BBToken] -> Either TreeError (Forest BBLabel)
 -- We use @'Tree' 'BBLabel'@ only as another intermediate structure because it carries no guarantee that the data is semantically valid -- a 'BBPlain'-value semantically has no children.
 --
 -- The use of 'Tree' was still deemed desirable because the morphism to a more sensible structure is straightforward and 'Data.Tree.Zipper' provides all the tools needed to implement 'rose' in a sensible fashion
-rose = fmap Z.toForest . flip rose' (Z.fromForest [])
+rose = fmap Z.toForest . foldM (flip rose') (Z.fromForest [])
   where
-    rose' :: [BBToken] -> TreePos Empty BBLabel -> Either TreeError (TreePos Empty BBLabel)
-    rose' [] = return
-    rose' (x:xs) = (>>= rose' xs) . rose'' x
-
-    rose'' (BBStr t) = return . Z.nextSpace . Z.insert (Node (BBPlain t) [])
-    rose'' (BBOpen t attrs) = return . Z.children . Z.insert (Node (BBTag t $ Map.fromList attrs) [])
-    rose'' (BBContained t attrs) = return . Z.nextSpace . Z.insert (Node (BBTag t $ Map.fromList attrs) [])
-    rose'' (BBClose t) = close t -- for more pointless
+    rose' (BBStr t) = return . Z.nextSpace . Z.insert (Node (BBPlain t) [])
+    rose' (BBOpen t attrs) = return . Z.children . Z.insert (Node (BBTag t $ Map.fromList attrs) [])
+    rose' (BBContained t attrs) = return . Z.nextSpace . Z.insert (Node (BBTag t $ Map.fromList attrs) [])
+    rose' (BBClose t) = close t -- for more pointless
 
     close :: Text -> TreePos Empty BBLabel -> Either TreeError (TreePos Empty BBLabel)
     close tag pos = do