diff --git a/Data/List/Extras.hs b/Data/List/Extras.hs
--- a/Data/List/Extras.hs
+++ b/Data/List/Extras.hs
@@ -2,20 +2,23 @@
 {-# OPTIONS_GHC -Wall -fwarn-tabs #-}
 
 ----------------------------------------------------------------
---                                                  ~ 2008.07.25
+--                                                  ~ 2010.04.05
 -- |
 -- Module      :  Data.List.Extras
--- Copyright   :  Copyright (c) 2007--2008 wren ng thornton
+-- Copyright   :  Copyright (c) 2007--2010 wren ng thornton
 -- License     :  BSD3
 -- Maintainer  :  wren@community.haskell.org
 -- Stability   :  stable
 -- Portability :  portable
 --
--- This module provides a single header for all @Data.List.Extras.*@ modules
+-- This module provides a single header for all @Data.List.Extras.*@
+-- modules and provides a small number of other utility functions.
 ----------------------------------------------------------------
 
 module Data.List.Extras
-    ( module Data.List.Extras.LazyLength
+    (
+      list
+    , module Data.List.Extras.LazyLength
     , module Data.List.Extras.Pair
     , module Data.List.Extras.Argmax
     ) where
@@ -23,5 +26,14 @@
 import Data.List.Extras.LazyLength
 import Data.List.Extras.Pair
 import Data.List.Extras.Argmax
+
+-- | Pattern matching for lists, as a first-class function. (Could
+-- also be considered as a non-recursive 'foldr'.) If the list
+-- argument is @[]@ then the default argument is returned; otherwise
+-- the function is called with the head and tail of the list.
+list :: (a -> [a] -> b) -> b -> [a] -> b
+list _ z []     = z
+list f _ (x:xs) = f x xs 
+
 ----------------------------------------------------------------
 ----------------------------------------------------------- fin.
diff --git a/Data/List/Extras/Argmax.hs b/Data/List/Extras/Argmax.hs
--- a/Data/List/Extras/Argmax.hs
+++ b/Data/List/Extras/Argmax.hs
@@ -5,7 +5,7 @@
 --                                                  ~ 2008.08.17
 -- |
 -- Module      :  Data.List.Extras.ArgMax
--- Copyright   :  Copyright (c) 2007--2008 wren ng thornton
+-- Copyright   :  Copyright (c) 2007--2009 wren ng thornton
 -- License     :  BSD3
 -- Maintainer  :  wren@community.haskell.org
 -- Stability   :  experimental
diff --git a/Data/List/Extras/LazyLength.hs b/Data/List/Extras/LazyLength.hs
--- a/Data/List/Extras/LazyLength.hs
+++ b/Data/List/Extras/LazyLength.hs
@@ -13,7 +13,7 @@
 --                                                  ~ 2009.04.02
 -- |
 -- Module      :  Data.List.Extras.LazyLength
--- Copyright   :  Copyright (c) 2007--2008 wren ng thornton
+-- Copyright   :  Copyright (c) 2007--2009 wren ng thornton
 -- License     :  BSD3
 -- Maintainer  :  wren@community.haskell.org
 -- Stability   :  stable
diff --git a/Data/List/Extras/Pair.hs b/Data/List/Extras/Pair.hs
--- a/Data/List/Extras/Pair.hs
+++ b/Data/List/Extras/Pair.hs
@@ -2,10 +2,10 @@
 {-# OPTIONS_GHC -Wall -fwarn-tabs #-}
 
 ----------------------------------------------------------------
---                                                  ~ 2009.04.02
+--                                                  ~ 2010.05.31
 -- |
 -- Module      :  Data.List.Extras.Pair
--- Copyright   :  Copyright (c) 2007--2008 wren ng thornton
+-- Copyright   :  Copyright (c) 2007--2009 wren ng thornton
 -- License     :  BSD3
 -- Maintainer  :  wren@community.haskell.org
 -- Stability   :  stable
@@ -51,8 +51,7 @@
 
 
 -- | A version of 'zip' that uses a user-defined list homomorphism.
-zipBy :: ((a,b) -> m (a,b) -> m (a,b)) -> m (a,b)
-      -> [a] -> [b] -> m (a,b)
+zipBy :: ((a,b) -> d -> d) -> d -> [a] -> [b] -> d
 zipBy  = zipWithBy (,)
 
 
@@ -91,6 +90,8 @@
     pairWB (x:xs) (y:ys) cc = pairWB xs ys (cc . f (k x y))
     pairWB []     []     cc = Just (cc z)
     pairWB _      _      _  = Nothing
+
+-- TODO: we could make this more general still by fusing @f@ and @k@, which we'd often want to do anyways if we're using this full form.
 
 ----------------------------------------------------------------
 
diff --git a/Prelude/Listless.hs b/Prelude/Listless.hs
--- a/Prelude/Listless.hs
+++ b/Prelude/Listless.hs
@@ -5,7 +5,7 @@
 --                                                  ~ 2008.07.20
 -- |
 -- Module      :  Prelude.Listless
--- Copyright   :  Copyright (c) 2007--2008 wren ng thornton
+-- Copyright   :  Copyright (c) 2007--2009 wren ng thornton
 -- License     :  BSD3
 -- Maintainer  :  wren@community.haskell.org
 -- Stability   :  stable
diff --git a/list-extras.cabal b/list-extras.cabal
--- a/list-extras.cabal
+++ b/list-extras.cabal
@@ -1,13 +1,13 @@
 ----------------------------------------------------------------
--- wren ng thornton <wren@community.haskell.org>    ~ 2009.04.02
+-- wren ng thornton <wren@community.haskell.org>    ~ 2010.05.31
 ----------------------------------------------------------------
 
 Name:           list-extras
-Version:        0.3.0
+Version:        0.4.0
 Cabal-Version:  >= 1.2
 Build-Type:     Simple
 Stability:      stable
-Copyright:      Copyright (c) 2007--2008 wren ng thornton
+Copyright:      Copyright (c) 2007--2010 wren ng thornton
 License:        BSD3
 License-File:   LICENSE
 Author:         wren ng thornton
@@ -26,13 +26,21 @@
                 maintain a separate package I can share the
                 @Data.List.Extras.Foo@ namespace.
 
+
+Flag preludeInBase
+    Description: base-4.0 deprecated Prelude which is imported qualified
+    Default:     False
+
 Library
     Exposed-Modules: Prelude.Listless
                    , Data.List.Extras
                    , Data.List.Extras.Argmax
                    , Data.List.Extras.LazyLength
                    , Data.List.Extras.Pair
-    Build-Depends:   base
+    if flag(preludeInBase)
+        Build-Depends: base >= 4
+    else
+        Build-Depends: base < 3
 
 ----------------------------------------------------------------
 ----------------------------------------------------------- fin.