diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -49,9 +49,14 @@
 
 ## Vim
 
-Basic support is provided through [vim/hindent.vim](https://github.com/chrisdone/hindent/blob/master/vim/hindent.vim),
-which sets hindent as the formatter used by `gq` for haskell files. The formatting style
-defaults to `fundamental` but can be configured by setting `g:hindent_style` to the desired style.
+The `'formatprg'` option lets you use an external program (like hindent) to
+format your text. Put the following line into ~/.vim/ftplugin/haskell.vim
+to set this option for Haskell files:
+
+    setlocal formatprg=hindent\ --style\ chris-done
+
+Then you can format with hindent using `gq`. Read `:help gq` and `help
+'formatprg'` for more details.
 
 Note that unlike in emacs you have to take care of selecting a sensible buffer region as input to
 hindent yourself. If that is too much trouble you can try [vim-textobj-haskell](https://github.com/gilligan/vim-textobj-haskell) which provides a text object for top level bindings.
diff --git a/benchmarks/BigDeclarations.hs b/benchmarks/BigDeclarations.hs
new file mode 100644
--- /dev/null
+++ b/benchmarks/BigDeclarations.hs
@@ -0,0 +1,17 @@
+listPrinters =
+  [(''[]
+   ,\(typeVariable:_) _automaticPrinter ->
+      (let presentVar = varE (presentVarName typeVariable)
+       in lamE [varP (presentVarName typeVariable)]
+               [|(let typeString = "[" ++ fst $(presentVar) ++ "]"
+                  in (typeString
+                     ,\xs ->
+                        case fst $(presentVar) of
+                          "GHC.Types.Char" ->
+                            ChoicePresentation
+                              "String"
+                              [("String",undefined)
+                              ,("List of characters",undefined)]
+                          _ ->
+                            ListPresentation typeString
+                                             (map (snd $(presentVar)) xs)))|]))]
diff --git a/hindent.cabal b/hindent.cabal
--- a/hindent.cabal
+++ b/hindent.cabal
@@ -1,5 +1,5 @@
 name:                hindent
-version:             4.6.3
+version:             4.6.4
 synopsis:            Extensible Haskell pretty printer
 description:         Extensible Haskell pretty printer. Both a library and an executable.
                      .
@@ -15,8 +15,9 @@
 cabal-version:       >=1.8
 homepage: http://www.github.com/chrisdone/hindent
 bug-reports: https://github.com/chrisdone/hindent/issues
-data-files:          elisp/hindent.el vim/hindent.vim
+data-files:          elisp/hindent.el
 extra-source-files:  README.md
+                     benchmarks/BigDeclarations.hs
                      test/chris-done/expected/*.exp
                      test/chris-done/tests/*.test
                      test/gibiansky/expected/*.exp
@@ -44,7 +45,6 @@
                      HIndent.Styles.Cramer
   build-depends:     base >= 4.7 && <5
                    , containers
-                   , data-default
                    , haskell-src-exts >= 1.17
                    , monad-loops
                    , mtl
@@ -78,7 +78,6 @@
   main-is: Spec.hs
   build-depends:     base >= 4 && <5
                    , hindent
-                   , data-default
                    , haskell-src-exts
                    , monad-loops
                    , mtl
diff --git a/src/HIndent/Pretty.hs b/src/HIndent/Pretty.hs
--- a/src/HIndent/Pretty.hs
+++ b/src/HIndent/Pretty.hs
@@ -26,7 +26,7 @@
   , int
   , string
   -- * Common node types
-  , maybeCtx
+  , withCtx
   , printComment
   , printComments
   , withCaseContext
@@ -399,13 +399,16 @@
 nullBinds (BDecls _ x) = null x
 nullBinds (IPBinds _ x) = null x
 
--- | Maybe render a class context.
-maybeCtx :: MonadState (PrintState s) m => Maybe (Context NodeInfo) -> m ()
-maybeCtx =
-  maybe (return ())
-        (\p ->
-           pretty p >>
-           write " => ")
+-- | Render a type with a context, or not.
+withCtx :: (MonadState (PrintState s) m
+           ,Pretty ast)
+        => Maybe (ast NodeInfo) -> m b -> m b
+withCtx Nothing m = m
+withCtx (Just ctx) m =
+  do pretty ctx
+     write " =>"
+     newline
+     m
 
 -- | Maybe render an overlap definition.
 maybeOverlap :: MonadState (PrintState s) m => Maybe (Overlap NodeInfo) -> m ()
@@ -441,7 +444,8 @@
     case ctx of
       CxSingle _ a -> pretty a
       CxTuple _ as ->
-        parens (commas (map pretty as))
+        parens (prefixedLined ","
+                              (map pretty as))
       CxEmpty _ -> parens (return ())
 
 instance Pretty Pat where
@@ -535,8 +539,7 @@
                     do write "forall "
                        spaced (map pretty ts)
                        write ". ")
-               (depend (maybeCtx ctx)
-                       (pretty ty))
+               (withCtx ctx (pretty ty))
       TyFun _ a b ->
         depend (do pretty a
                    write " -> ")
@@ -828,14 +831,14 @@
   lined (map pretty matches)
 decl (ClassDecl _ ctx dhead fundeps decls) =
   do depend (write "class ")
-            (depend (maybeCtx ctx)
-                    (depend (do pretty dhead
-                                space)
-                            (depend (unless (null fundeps)
-                                            (do write " | "
-                                                commas (map pretty fundeps)))
-                                    (unless (null (fromMaybe [] decls))
-                                            (write " where")))))
+            (withCtx ctx
+                     (depend (do pretty dhead
+                                 space)
+                             (depend (unless (null fundeps)
+                                             (do write " | "
+                                                 commas (map pretty fundeps)))
+                                     (unless (null (fromMaybe [] decls))
+                                             (write " where")))))
      unless (null (fromMaybe [] decls))
             (do newline
                 indentSpaces <- getIndentSpaces
@@ -851,12 +854,12 @@
 decl (DataDecl _ dataornew ctx dhead condecls mderivs) =
   do depend (do pretty dataornew
                 space)
-            (depend (maybeCtx ctx)
-                    (do pretty dhead
-                        case condecls of
-                          [] -> return ()
-                          [x] -> singleCons x
-                          xs -> multiCons xs))
+            (withCtx ctx
+                     (do pretty dhead
+                         case condecls of
+                           [] -> return ()
+                           [x] -> singleCons x
+                           xs -> multiCons xs))
      indentSpaces <- getIndentSpaces
      case mderivs of
        Nothing -> return ()
@@ -945,14 +948,13 @@
       ClsDecl _ d -> pretty d
       ClsDataFam _ ctx h mkind ->
         depend (write "data ")
-               (depend (maybeCtx ctx)
-                       (do pretty h
-                           (case mkind of
-                              Nothing ->
-                                return ()
-                              Just kind ->
-                                do write " :: "
-                                   pretty kind)))
+               (withCtx ctx
+                        (do pretty h
+                            (case mkind of
+                               Nothing -> return ()
+                               Just kind ->
+                                 do write " :: "
+                                    pretty kind)))
       ClsTyFam _ h mkind ->
         depend (write "type ")
                (depend (pretty h)
@@ -1083,7 +1085,7 @@
                        (do write "forall "
                            spaced (map pretty (fromMaybe [] tyvars))
                            write ". "))
-               (depend (maybeCtx ctx)
+               (withCtx ctx
                        (pretty d))
 
 instance Pretty Rhs where
@@ -1116,9 +1118,7 @@
     do case mvarbinds of
          Nothing -> return ()
          Just xs -> spaced (map pretty xs)
-       depend (maybeCtx mctx)
-              (pretty ihead)
-
+       withCtx mctx (pretty ihead)
 
 instance Pretty InstHead where
   prettyInternal x =
@@ -1283,7 +1283,18 @@
   prettyInternal = pretty'
 
 instance Pretty ModuleHead where
-  prettyInternal = pretty'
+  prettyInternal (ModuleHead _ name mwarnings mexports) =
+    do write "module "
+       pretty name
+       maybe (return ()) pretty mwarnings
+       maybe (return ())
+             (\exports ->
+                do newline
+                   indented 2 (pretty exports)
+                   newline
+                   space)
+             mexports
+       write " where"
 
 instance Pretty ModulePragma where
   prettyInternal = pretty'
@@ -1305,7 +1316,9 @@
   prettyInternal = pretty'
 
 instance Pretty ExportSpecList where
-  prettyInternal = pretty'
+  prettyInternal (ExportSpecList _ es) =
+    parens (prefixedLined ","
+                          (map pretty es))
 
 instance Pretty ExportSpec where
   prettyInternal = pretty'
diff --git a/src/HIndent/Styles/Cramer.hs b/src/HIndent/Styles/Cramer.hs
--- a/src/HIndent/Styles/Cramer.hs
+++ b/src/HIndent/Styles/Cramer.hs
@@ -644,11 +644,13 @@
 -- Fix whitespace before 'where' in class decl
 extDecl (ClassDecl _ mcontext declhead fundeps mdecls) =
   do depend (write "class ") $
-       depend (maybeCtx mcontext) $
-         depend (pretty declhead) $
-           depend (unless (null fundeps) $
-               write " | " >> inter (write ", ") (map pretty fundeps)) $
-             when (isJust mdecls) $ write " where"
+       withCtx mcontext $
+       depend (pretty declhead) $
+       depend (unless (null fundeps) $
+               write " | " >>
+               inter (write ", ")
+                     (map pretty fundeps)) $
+       when (isJust mdecls) $ write " where"
      maybeM_ mdecls $
        \decls ->
          do newline
diff --git a/src/HIndent/Styles/Fundamental.hs b/src/HIndent/Styles/Fundamental.hs
--- a/src/HIndent/Styles/Fundamental.hs
+++ b/src/HIndent/Styles/Fundamental.hs
@@ -7,9 +7,7 @@
 
 import HIndent.Types
 
-import Data.Default
 
-
 -- | Empty state.
 data State = State
 
@@ -21,5 +19,5 @@
         ,styleDescription = "This style adds no extensions to the built-in printer."
         ,styleInitialState = State
         ,styleExtenders = []
-        ,styleDefConfig = def
+        ,styleDefConfig = defaultConfig
         ,styleCommentPreprocessor = return}
diff --git a/src/HIndent/Styles/Gibiansky.hs b/src/HIndent/Styles/Gibiansky.hs
--- a/src/HIndent/Styles/Gibiansky.hs
+++ b/src/HIndent/Styles/Gibiansky.hs
@@ -947,7 +947,7 @@
 
   -- Header
   depend (write "class ") $
-    depend (maybeCtx ctx) $
+    withCtx ctx $
       depend (pretty dhead >> space) $
         depend (unless (null fundeps) (write " | " >> commas (map pretty fundeps))) $
           unless noDecls (write "where")
diff --git a/src/HIndent/Styles/JohanTibell.hs b/src/HIndent/Styles/JohanTibell.hs
--- a/src/HIndent/Styles/JohanTibell.hs
+++ b/src/HIndent/Styles/JohanTibell.hs
@@ -171,6 +171,21 @@
 
 -- | Expression customizations.
 exp :: Exp NodeInfo -> Printer s ()
+-- | Do after lambda should swing.
+exp (Lambda _ pats (Do l stmts)) =
+  do
+     (fits,st) <-
+       fitsOnOneLine
+         (do write "\\"
+             spaced (map pretty pats)
+             write " -> "
+             pretty (Do l stmts))
+     if fits
+        then put st
+        else swing (do write "\\"
+                       spaced (map pretty pats)
+                       write " -> do")
+                   (lined (map pretty stmts))
 -- | Space out tuples.
 exp (Tuple _ boxed exps) =
   depend (write (case boxed of
@@ -292,8 +307,14 @@
 
 -- | Format contexts with spaces and commas between class constraints.
 context :: Context NodeInfo -> Printer s ()
-context (CxTuple _ asserts) =
-  parens $ inter (comma >> space) $ map pretty asserts
+context ctx@(CxTuple _ asserts) =
+  do (fits,st) <-
+       fitsOnOneLine
+         (parens (inter (comma >> space)
+                        (map pretty asserts)))
+     if fits
+        then put st
+        else prettyNoExt ctx
 context ctx = prettyNoExt ctx
 
 unboxParens :: MonadState (PrintState s) m => m a -> m a
@@ -373,9 +394,9 @@
   | any isRecord condecls =
     do depend (do pretty dataornew
                   unless (null condecls) space)
-              (depend (maybeCtx ctx)
-                      (do pretty dhead
-                          multiCons condecls))
+              (withCtx ctx
+                       (do pretty dhead
+                           multiCons condecls))
        case mderivs of
          Nothing -> return ()
          Just derivs -> pretty derivs
@@ -388,17 +409,13 @@
 -- | Use special record display, used by 'dataDecl' in a record scenario.
 qualConDecl :: QualConDecl NodeInfo -> Printer s ()
 qualConDecl x =
-    case x of
-        QualConDecl _ tyvars ctx d ->
-            depend
-                (unless
-                     (null (fromMaybe [] tyvars))
+  case x of
+    QualConDecl _ tyvars ctx d ->
+      depend (unless (null (fromMaybe [] tyvars))
                      (do write "forall "
                          spaced (map pretty (fromMaybe [] tyvars))
                          write ". "))
-                (depend
-                     (maybeCtx ctx)
-                     (recDecl d))
+             (withCtx ctx (recDecl d))
 
 -- | Fields are preceded with a space.
 conDecl :: ConDecl NodeInfo -> Printer s ()
diff --git a/src/HIndent/Types.hs b/src/HIndent/Types.hs
--- a/src/HIndent/Types.hs
+++ b/src/HIndent/Types.hs
@@ -24,7 +24,6 @@
 import Control.Monad.State.Strict (MonadState(..),StateT)
 import Control.Monad.Trans.Maybe
 import Data.Data
-import Data.Default
 import Data.Functor.Identity
 import Data.Int (Int64)
 import Data.Text (Text)
@@ -80,15 +79,12 @@
          ,configClearEmptyLines :: !Bool  -- ^ Remove spaces on lines that are otherwise empty?
          }
 
-instance Default Config where
-  def =
-    Config {configMaxColumns = 80
-           ,configIndentSpaces = 2
-           ,configClearEmptyLines = False}
-
 -- | Default style configuration.
 defaultConfig :: Config
-defaultConfig = def
+defaultConfig =
+  Config {configMaxColumns = 80
+         ,configIndentSpaces = 2
+         ,configClearEmptyLines = False}
 
 -- | Information for each node in the AST.
 data NodeInfo =
diff --git a/src/main/Main.hs b/src/main/Main.hs
--- a/src/main/Main.hs
+++ b/src/main/Main.hs
@@ -27,6 +27,9 @@
 import           System.Environment
 import           System.IO
 import           Text.Read
+import           Control.Exception
+import           GHC.IO.Exception
+import           Foreign.C.Error
 
 -- | Main entry point.
 main :: IO ()
@@ -44,7 +47,10 @@
                   (either error T.toLazyText (reformat style (Just exts) text))
                 hFlush h
                 hClose h
-                renameFile fp filepath
+                let exdev e = if ioe_errno e == Just ((\(Errno a) -> a) eXDEV)
+                                  then copyFile fp filepath >> removeFile fp
+                                  else throw e
+                renameFile fp filepath `catch` exdev
            Nothing ->
              T.interact (either error T.toLazyText . reformat style (Just exts))
        Failed (Wrap (Stopped Version) _) ->
diff --git a/test/chris-done/expected/12.exp b/test/chris-done/expected/12.exp
--- a/test/chris-done/expected/12.exp
+++ b/test/chris-done/expected/12.exp
@@ -2,38 +2,122 @@
 
 module Main where
 
-module Main () where
+module Main
+  ()
+  where
 
-module Main () where
+module Main
+  ()
+  where
 
-module Main (main) where
+module Main
+  (main)
+  where
 
-module Main (main, main2) where
+module Main
+  (main
+  ,main2)
+  where
 
-module Main (main, main2) where
+module Main
+  (main
+  ,main2)
+  where
 
-module Main (main, main2, main3) where
+module Main
+  (main
+  ,main2
+  ,main3)
+  where
 
-module Main (main, main2, main3, main4) where
+module Main
+  (main
+  ,main2
+  ,main3
+  ,main4)
+  where
 
-module Main (main, main2, main3, main4) where
+module Main
+  (main
+  ,main2
+  ,main3
+  ,main4)
+  where
 
-module Main (main, main2, main3, main4, main5) where
+module Main
+  (main
+  ,main2
+  ,main3
+  ,main4
+  ,main5)
+  where
 
-module Main (main, main2, main3, main4, main5) where
+module Main
+  (main
+  ,main2
+  ,main3
+  ,main4
+  ,main5)
+  where
 
-module Main (main, main2, main3, main4, main5, main6) where
+module Main
+  (main
+  ,main2
+  ,main3
+  ,main4
+  ,main5
+  ,main6)
+  where
 
-module Main (main, main2, main3, main4, main5, main6) where
+module Main
+  (main
+  ,main2
+  ,main3
+  ,main4
+  ,main5
+  ,main6)
+  where
 
-module Main (main, main2, main3, main4, main5) where
+module Main
+  (
+   -- * A thing
+   main
+  ,main2
+  ,
+   -- * Another thing
+   main3
+  ,main4
+  ,
+   -- ** Another thing
+   main5)
+  where
 
-module Main (main, main2, main3, main4, main5) where
+module Main
+  (
+   -- * A thing
+   main
+  ,main2
+  ,
+   -- * Another thing
+   main3
+  ,main4
+  ,
+   -- ** Another thing
+   main5)
+  where
 
-module Main (main) where
+module Main
+  (main)
+  where
 >
 import Text.Hello
 
-module Main (main, main2, main3, main4, main5) where
+module Main
+  (main
+  ,main2
+  ,main3
+  ,main4
+  ,main5)
+  where
 >
 import Text.Hello
diff --git a/test/chris-done/expected/2.exp b/test/chris-done/expected/2.exp
--- a/test/chris-done/expected/2.exp
+++ b/test/chris-done/expected/2.exp
@@ -5,7 +5,8 @@
 fun :: Class a
     => a -> b -> c
 
-fun :: (Class a,Class b)
+fun :: (Class a
+       ,Class b)
     => a -> b -> c
 
 fun :: a -> b -> c
@@ -20,8 +21,10 @@
 
 fun :: a -> b -> c -- ^ Hello
 
-fun :: (Class a,Class b)
+fun :: (Class a
+       ,Class b)
     => a -> b -> c -- ^ Hello
 
-fun :: (Class a,Class b)
+fun :: (Class a
+       ,Class b)
     => a -> b -> c -- ^ Hello
diff --git a/test/fundamental/expected/12.exp b/test/fundamental/expected/12.exp
--- a/test/fundamental/expected/12.exp
+++ b/test/fundamental/expected/12.exp
@@ -2,38 +2,122 @@
 
 module Main where
 
-module Main () where
+module Main
+  ()
+  where
 
-module Main () where
+module Main
+  ()
+  where
 
-module Main (main) where
+module Main
+  (main)
+  where
 
-module Main (main, main2) where
+module Main
+  (main
+  ,main2)
+  where
 
-module Main (main, main2) where
+module Main
+  (main
+  ,main2)
+  where
 
-module Main (main, main2, main3) where
+module Main
+  (main
+  ,main2
+  ,main3)
+  where
 
-module Main (main, main2, main3, main4) where
+module Main
+  (main
+  ,main2
+  ,main3
+  ,main4)
+  where
 
-module Main (main, main2, main3, main4) where
+module Main
+  (main
+  ,main2
+  ,main3
+  ,main4)
+  where
 
-module Main (main, main2, main3, main4, main5) where
+module Main
+  (main
+  ,main2
+  ,main3
+  ,main4
+  ,main5)
+  where
 
-module Main (main, main2, main3, main4, main5) where
+module Main
+  (main
+  ,main2
+  ,main3
+  ,main4
+  ,main5)
+  where
 
-module Main (main, main2, main3, main4, main5, main6) where
+module Main
+  (main
+  ,main2
+  ,main3
+  ,main4
+  ,main5
+  ,main6)
+  where
 
-module Main (main, main2, main3, main4, main5, main6) where
+module Main
+  (main
+  ,main2
+  ,main3
+  ,main4
+  ,main5
+  ,main6)
+  where
 
-module Main (main, main2, main3, main4, main5) where
+module Main
+  (
+   -- * A thing
+   main
+  ,main2
+  ,
+   -- * Another thing
+   main3
+  ,main4
+  ,
+   -- ** Another thing
+   main5)
+  where
 
-module Main (main, main2, main3, main4, main5) where
+module Main
+  (
+   -- * A thing
+   main
+  ,main2
+  ,
+   -- * Another thing
+   main3
+  ,main4
+  ,
+   -- ** Another thing
+   main5)
+  where
 
-module Main (main) where
+module Main
+  (main)
+  where
 >
 import Text.Hello
 
-module Main (main, main2, main3, main4, main5) where
+module Main
+  (main
+  ,main2
+  ,main3
+  ,main4
+  ,main5)
+  where
 >
 import Text.Hello
diff --git a/test/fundamental/expected/2.exp b/test/fundamental/expected/2.exp
--- a/test/fundamental/expected/2.exp
+++ b/test/fundamental/expected/2.exp
@@ -2,9 +2,12 @@
 
 fun :: a -> f b -> g c d
 
-fun :: Class a => a -> b -> c
+fun :: Class a =>
+       a -> b -> c
 
-fun :: (Class a,Class b) => a -> b -> c
+fun :: (Class a
+       ,Class b) =>
+       a -> b -> c
 
 fun :: a -> b -> c
 
@@ -17,6 +20,10 @@
 
 fun :: a -> b -> c -- ^ Hello
 
-fun :: (Class a,Class b) => a -> b -> c -- ^ Hello
+fun :: (Class a
+       ,Class b) =>
+       a -> b -> c -- ^ Hello
 
-fun :: (Class a,Class b) => a -> b -> c -- ^ Hello
+fun :: (Class a
+       ,Class b) =>
+       a -> b -> c -- ^ Hello
diff --git a/test/gibiansky/expected/38.exp b/test/gibiansky/expected/38.exp
--- a/test/gibiansky/expected/38.exp
+++ b/test/gibiansky/expected/38.exp
@@ -1,7 +1,8 @@
 type X = Y
 >
 -- Comment
-instance A a => B a where
+instance A a =>
+         B a where
   x = y
 
 {-# INLINE x #-}
diff --git a/vim/hindent.vim b/vim/hindent.vim
deleted file mode 100644
--- a/vim/hindent.vim
+++ /dev/null
@@ -1,22 +0,0 @@
-if exists("g:loaded_hindent") || !executable("hindent")
-    finish
-endif
-let g:loaded_hindent = 1
-
-if !exists("g:hindent_style")
-    let g:hindent_style = "fundamental"
-endif
-
-function! FormatHaskell()
-    if !empty(v:char)
-        return 1
-    else
-        let l:filter = "hindent --style " . g:hindent_style
-        let l:command = v:lnum.','.(v:lnum+v:count-1).'!'.l:filter
-        execute l:command
-    endif
-endfunction
-
-if has("autocmd")
-  autocmd FileType haskell setlocal formatexpr=FormatHaskell()
-endif