diff --git a/library/Potoki/Consume.hs b/library/Potoki/Consume.hs
--- a/library/Potoki/Consume.hs
+++ b/library/Potoki/Consume.hs
@@ -11,8 +11,10 @@
   vector,
   concat,
   fold,
-  execState,
   foldInIO,
+  folding,
+  foldingInIO,
+  execState,
   writeBytesToFile,
   appendBytesToFile,
   deleteFiles,
@@ -31,6 +33,7 @@
 import qualified Potoki.Core.Produce as H
 import qualified Potoki.Core.Transform as J
 import qualified Potoki.Core.IO as L
+import qualified Potoki.Fetch as A
 import qualified Data.ByteString as C
 import qualified Data.Attoparsec.ByteString as E
 import qualified Data.Attoparsec.Text as F
@@ -149,11 +152,6 @@
     build fetch !accumulator =
       join (fetch (pure (finish accumulator)) (\ !input -> build fetch (step accumulator input)))
 
-{-# INLINE execState #-}
-execState :: (a -> O.State s b) -> s -> Consume a s
-execState stateFn initialState = 
-  fold $ D.Fold (\currentState input -> snd $ O.runState (stateFn input) currentState) initialState id
-
 {-# INLINABLE foldInIO #-}
 foldInIO :: D.FoldM IO input output -> Consume input output
 foldInIO (D.FoldM step init finish) =
@@ -161,6 +159,35 @@
   where
     build fetch !accumulator =
       join (fetch (finish accumulator) (\ !input -> step accumulator input >>= build fetch))
+
+{-# INLINABLE folding #-}
+folding :: D.Fold a b -> Consume a c -> Consume a (b, c)
+folding (D.Fold step init extract) (Consume consumeIO) =
+  Consume $ \ fetch -> do
+    foldStateRef <- newIORef init
+    consumptionResult <-
+      consumeIO (A.handlingElements (\ element -> do
+        !newState <- flip step element <$> readIORef foldStateRef
+        writeIORef foldStateRef newState) fetch)
+    foldResult <- extract <$> readIORef foldStateRef
+    return (foldResult, consumptionResult)
+
+{-# INLINABLE foldingInIO #-}
+foldingInIO :: D.FoldM IO a b -> Consume a c -> Consume a (b, c)
+foldingInIO (D.FoldM step init extract) (Consume consumeIO) =
+  Consume $ \ fetch -> do
+    foldStateRef <- newIORef =<< init
+    consumptionResult <-
+      consumeIO (A.handlingElements (\ element -> do
+        !newState <- flip step element =<< readIORef foldStateRef
+        writeIORef foldStateRef newState) fetch)
+    foldResult <- extract =<< readIORef foldStateRef
+    return (foldResult, consumptionResult)
+
+{-# INLINE execState #-}
+execState :: (a -> O.State s b) -> s -> Consume a s
+execState stateFn initialState = 
+  fold $ D.Fold (\currentState input -> snd $ O.runState (stateFn input) currentState) initialState id
 
 {-# INLINABLE runParseResult #-}
 runParseResult :: (Monoid input, Eq input) => (input -> I.IResult input output) -> Consume input (Either Text output)
diff --git a/library/Potoki/Fetch.hs b/library/Potoki/Fetch.hs
--- a/library/Potoki/Fetch.hs
+++ b/library/Potoki/Fetch.hs
@@ -96,3 +96,11 @@
         writeIORef indexRef (succ index)
         return (just (C.unsafeIndex vector index))
       else return nil
+
+{-# INLINABLE handlingElements #-}
+handlingElements :: (element -> IO ()) -> Fetch element -> Fetch element
+handlingElements xRay (Fetch fetchIO) =
+  Fetch $ \ nil just ->
+    join $ fetchIO
+      (return nil)
+      (\ element -> xRay element $> just element)
diff --git a/potoki.cabal b/potoki.cabal
--- a/potoki.cabal
+++ b/potoki.cabal
@@ -1,7 +1,7 @@
 name:
   potoki
 version:
-  0.11.2
+  0.11.3
 synopsis:
   Simple streaming in IO
 description: