1 files changed, 7 insertions, 3 deletions

diff --git a/src/Wavefront.hs b/src/Wavefront.hs
index 2131d96..638b849 100644
--- a/src/Wavefront.hs
+++ b/src/Wavefront.hs
@@ -152,6 +152,10 @@ mzeroOBJ = OBJ
 parse :: L.ByteString -> OBJ Vector
 parse bs = Rank2.fmap (Vector.fromList . DList.toList) obj
  where
-    b = objBookKeeping buildOBJ
-    substvars = ObjConfig IntMap.empty
-    (obj,_) = execState (runStateT (parseOBJ b substvars bs) emptyCounts) (mzeroOBJ,blankElement)
+    go = parseCustom buildOBJ (const $ return ()) bs
+    (obj,_) = execState go (mzeroOBJ,blankElement)
+
+parseCustom :: Monad m => ObjBuilder m -> (OBJ Count -> m b) -> L.ByteString -> m b
+parseCustom builder finish bs = do
+    counts <- execStateT (parseOBJ (objBookKeeping builder) (ObjConfig IntMap.empty) bs) emptyCounts
+    finish counts