diff --git a/CHANGELOG b/CHANGELOG
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,7 @@
+# 0.4.5.0
+
+- added split
+
 # 0.4.4.0
 
 - deprecated quiesceWith
diff --git a/benchmarks/benchmarks.hs b/benchmarks/benchmarks.hs
--- a/benchmarks/benchmarks.hs
+++ b/benchmarks/benchmarks.hs
@@ -1,8 +1,21 @@
 module Main where
 
+import Data.Foldable
 import qualified Control.Foldl as L
-import qualified Control.Foldl.Transduce
+import Control.Foldl.Transduce
+import Lens.Family
 
--- TBD
+import Criterion.Main
+
 main :: IO ()
-main = return ()
+main = defaultMain [
+        bgroup "sum" [
+             bench "without trans" (nf 
+                (L.fold L.sum)
+                (take 500000 (cycle [1::Int,-1])))
+        ,
+             bench "with trans"  (nf 
+                (L.fold (folds (chunksOf 1) L.list (L.handles (folding toList) L.sum)))
+                (take 500000 (cycle [1::Int,-1])))
+        ]        
+    ]
diff --git a/foldl-transduce.cabal b/foldl-transduce.cabal
--- a/foldl-transduce.cabal
+++ b/foldl-transduce.cabal
@@ -1,5 +1,5 @@
 Name: foldl-transduce
-Version: 0.4.4.0
+Version: 0.4.5.0
 Cabal-Version: >=1.8.0.2
 Build-Type: Simple
 License: BSD3
@@ -74,10 +74,11 @@
     Type:             exitcode-stdio-1.0
     HS-Source-Dirs:   benchmarks
     Main-Is:          benchmarks.hs
-    GHC-Options:     -O2 -Wall -rtsopts 
+    GHC-Options: -O2 -Wall -rtsopts 
 
     Build-Depends:
         base         >= 4.4     && < 5  ,
         criterion    >= 1.1.0.0 && < 1.2,
+        lens-family-core >= 1.2.0       ,
         foldl                           ,
         foldl-transduce
diff --git a/src/Control/Foldl/Transduce.hs b/src/Control/Foldl/Transduce.hs
--- a/src/Control/Foldl/Transduce.hs
+++ b/src/Control/Foldl/Transduce.hs
@@ -68,6 +68,7 @@
     ,   surroundIO
         -- * Splitters
     ,   chunksOf
+    ,   split
     ,   splitAt
     ,   chunkedSplitAt
     ,   splitLast
@@ -97,7 +98,7 @@
     ,   quiesceWith
     ) where
 
-import Prelude hiding (splitAt,break)
+import Prelude hiding (split,splitAt,break)
 
 import Data.Functor
 import Data.Bifunctor
@@ -128,7 +129,7 @@
 >>> import Control.Foldl.Transduce
 >>> import Control.Applicative
 >>> import qualified Control.Comonad.Cofree as C
->>> import Prelude hiding (splitAt,break)
+>>> import Prelude hiding (split,splitAt,break)
 
 -}
 
@@ -994,25 +995,55 @@
                 (Nothing,[prefix],[[suffix]])
         done = mempty
 
-data SplitWhenWhenState = 
-      SplitWhenConditionEncountered 
-    | SplitWhenConditionPending
+data SplitState = 
+      PreviousSeparator
+    | PreviousNonSeparator
 
 {-| 		
 
+>>> L.fold (folds (split (==2)) L.list L.list) [1,2,2,1,1,2,1]
+[[1],[],[1,1],[1]]
+
+>>> L.fold (folds (split (==2)) L.list L.list) [2,1,1,2]
+[[],[1,1],[]]
+
+-}
+split :: (a -> Bool) -> Transducer a a ()
+split predicate = 
+    Transducer step PreviousNonSeparator done 
+    where
+        step PreviousNonSeparator i = 
+            if predicate i 
+               then (PreviousSeparator,[],[])
+               else (PreviousNonSeparator,[i],[])
+        step PreviousSeparator i = 
+            if predicate i 
+               then (PreviousSeparator,[],[[]])
+               else (PreviousNonSeparator,[],[[i]])
+        done PreviousNonSeparator = mempty
+        done PreviousSeparator = ((),[],[[]])
+
+
+data BreakWhenState = 
+      BreakConditionEncountered 
+    | BreakConditionPending
+
+{-| 		
+
 >>> L.fold (bisect (break (>3)) (reify id) ignore L.list) [1..5]
 [1,2,3]
+
 -}
 break :: (a -> Bool) -> Transducer a a ()
 break predicate = 
-    Transducer step SplitWhenConditionPending done 
+    Transducer step BreakConditionPending done 
     where
-        step SplitWhenConditionPending i = 
+        step BreakConditionPending i = 
             if predicate i 
-               then (SplitWhenConditionEncountered,[],[[i]])
-               else (SplitWhenConditionPending,[i],[])
-        step SplitWhenConditionEncountered i = 
-               (SplitWhenConditionEncountered,[i],[])
+               then (BreakConditionEncountered,[],[[i]])
+               else (BreakConditionPending,[i],[])
+        step BreakConditionEncountered i = 
+               (BreakConditionEncountered,[i],[])
         done = mempty
 
 {-| Puts the last element of the input stream (if it exists) in a separate