diff --git a/Main.hs b/Main.hs
--- a/Main.hs
+++ b/Main.hs
@@ -1,15 +1,18 @@
+{-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE TemplateHaskell #-}
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE OverloadedStrings #-}
 
 import           Control.Applicative
+import           Control.Category.Structures
 import           Control.Lens
 import           Control.Lens.SemiIso
+import           Control.SIArrow
 import qualified Data.Attoparsec.Text.Lazy as AP
 import           Data.Map (Map)
 import qualified Data.Map as Map
 import           Data.Scientific (Scientific)
-import           Data.SemiIsoFunctor
 import qualified Data.Syntax as S
 import qualified Data.Syntax.Attoparsec.Text.Lazy as S
 import           Data.Syntax.Char (SyntaxText)
@@ -33,28 +36,28 @@
 
 $(makePrisms ''Value)
 
--- Indent is basically a Reader monad transformer.
+-- Indent is basically a Reader transformer.
 -- S.breakLine inserts a new line and correct indentation,
 -- but does not require any formatting when parsing (it just
 -- skips all white space).
 -- S.indented increases the indentation level.
 
 -- | Char encoded as 4 hex digits.
-hexCode :: SyntaxText syn => Indent syn Char
+hexCode :: SyntaxText syn => Indent syn () Char
 hexCode = from enum . bifoldl1_ (iso u f) /$/ sireplicate 4 S.digitHex
   where
     f (x, y) = 16 * x + y
     u 0 = Nothing
     u n = Just (n `quotRem` 16)
 
-string :: SyntaxText syn => Indent syn Text
+string :: SyntaxText syn => Indent syn () Text
 string =  S.packed /$/ S.char '"' */ simany character /* S.char '"'
   where
     character =  S.satisfy (\x -> x /= '"' && x /= '\\')
-             /|/ S.char '\\' */ escapedChar
+             /+/ S.char '\\' */ escapedChar
 
     escapedChar =  S.char 'u' */ hexCode
-               /|/ S.choice
+               /+/ S.choice
                    [ exact v /$/ S.char e
                    | (v, e) <- [ ('"', '"'), ('\\', '\\'), ('/', '/'), ('\b', 'b')
                                , ('\f', 'f'), ('\n', 'n') , ('\r', 'r'), ('\t', 't')]
@@ -63,7 +66,7 @@
 mapFromList :: Ord i => Iso' (Map i v) [(i, v)]
 mapFromList = iso Map.toList Map.fromList
 
-object :: SyntaxText syn => Indent syn Value
+object :: SyntaxText syn => Indent syn () Value
 object = _Object . mapFromList 
       /$~ S.char '{'
       /*/ S.indented (
@@ -73,7 +76,7 @@
       /*/ S.breakLine /*/ S.char '}'
   where field = string /* S.spaces_ /* S.char ':' /* S.spaces /*/ value
 
-array :: SyntaxText syn => Indent syn Value
+array :: SyntaxText syn => Indent syn () Value
 array = _Array 
      /$~ S.char '[' 
      /*/ S.indented (
@@ -82,14 +85,14 @@
          )
      /*/ S.breakLine /*/ S.char ']'
 
-value :: SyntaxText syn => Indent syn Value
+value :: SyntaxText syn => Indent syn () Value
 value =  _String /$/ string
-     /|/ _Number /$/ S.scientific
-     /|/ object
-     /|/ array
-     /|/ _Bool . exact True /$/ S.string "true"
-     /|/ _Bool . exact False /$/ S.string "false"
-     /|/ _Null /$/ S.string "null"
+     /+/ _Number /$/ S.scientific
+     /+/ object
+     /+/ array
+     /+/ _Bool . exact True /$/ S.string "true"
+     /+/ _Bool . exact False /$/ S.string "false"
+     /+/ _Null /$/ S.string "null"
      /?/ "Invalid JSON."
 
 main :: IO ()
@@ -98,10 +101,10 @@
     t <- T.getContents
 
     -- Indent with 2 spaces.
-    let tab :: SyntaxText syn => syn ()
+    let tab :: SyntaxText syn => syn () ()
         tab = sireplicate_ 2 (S.char ' ')
-        parser = S.getParser $ S.runIndent value tab
-        printer = S.runPrinter $ S.runIndent value tab
+        parser = S.getParser_ $ S.runIndent value tab
+        printer = S.runPrinter_ $ S.runIndent value tab
 
     -- Try to parse it.
     case AP.parse (AP.skipSpace *> parser <* AP.skipSpace <* AP.endOfInput) t of
diff --git a/syntax-example-json.cabal b/syntax-example-json.cabal
--- a/syntax-example-json.cabal
+++ b/syntax-example-json.cabal
@@ -1,16 +1,17 @@
 name:                syntax-example-json
-version:             0.2.0.0
+version:             1.0.0.0
 synopsis:            Example JSON parser/pretty-printer.
 description:
   Example JSON parser/pretty-printer.
   .
   Source code:
   .
-  * <https://github.com/Pawel834/syntax-example-json/blob/master/Main.hs Main.hs>
+  * <https://github.com/Pawel834/syntax-example-json/blob/7236aefc018ce3d968321b5b85ddcf80b46aeef4/Main.hs Main.hs>
   .
   Example input and output:
   .
   * <https://github.com/Pawel834/syntax-example-json/blob/master/in.json in.json>
+  .
   * <https://github.com/Pawel834/syntax-example-json/blob/master/out.json out.json>
 license:             MIT
 license-file:        LICENSE
@@ -28,5 +29,6 @@
 executable syntax-example-json
   main-is:             Main.hs
   default-language:    Haskell2010
-  build-depends:       base <5, semi-iso >= 0.5, syntax >= 0.3, syntax-attoparsec, syntax-printer,
+  build-depends:       base <5, semi-iso >= 1, syntax >= 1,
+                       syntax-attoparsec >= 1, syntax-printer >= 1,
                        containers, text, scientific, lens, attoparsec