diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,7 @@
+# 0.1.1.0
+
+- Added `showInfixl`, `showInfixr`, `showInfixl'`, `showInfixr'`.
+
+# 0.1.0.0
+
+Initial version
diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-# Show combinators
+# Show combinators [![Hackage](https://img.shields.io/hackage/v/show-combinators.svg)](https://hackage.haskell.org/package/show-combinators) [![Build Status](https://travis-ci.org/Lysxia/show-combinators.svg)](https://travis-ci.org/Lysxia/show-combinators)
 
 A minimal set of convenient combinators to write `Show` instances.
 
diff --git a/show-combinators.cabal b/show-combinators.cabal
--- a/show-combinators.cabal
+++ b/show-combinators.cabal
@@ -1,5 +1,5 @@
 name:                show-combinators
-version:             0.1.0.0
+version:             0.1.1.0
 synopsis:            Combinators to write Show instances
 description:
   A minimal pretty-printing library for Show instances in Haskell.
@@ -11,15 +11,17 @@
 copyright:           2018 Li-yao Xia
 category:            Text
 build-type:          Simple
-extra-source-files:  README.md
+extra-source-files:  README.md, CHANGELOG.md
 cabal-version:       >=1.10
+tested-with:         GHC == 7.10.3, GHC == 8.0.2, GHC == 8.2.2, GHC == 8.6.3
 
 library
   hs-source-dirs:      src
   exposed-modules:
     Text.Show.Combinators
   build-depends:
-    base >= 4.9 && < 5
+    -- This upper bound is conservative
+    base >= 4.8 && < 4.13
   ghc-options:         -Wall
   default-language:    Haskell2010
 
diff --git a/src/Text/Show/Combinators.hs b/src/Text/Show/Combinators.hs
--- a/src/Text/Show/Combinators.hs
+++ b/src/Text/Show/Combinators.hs
@@ -1,6 +1,4 @@
--- | Combinators for 'Show'
---
--- The combinators below can be used to write 'Show' instances.
+-- | Combinators to write 'Show' instances.
 --
 -- The following type illustrates the common use cases.
 --
@@ -14,20 +12,33 @@
 --
 -- instance 'Show' a => 'Show' (MyType a) where
 --   'showsPrec' = 'flip' precShows where
---     precShows (C a b) = 'showCon' "C" '@|' a '@|' b
---     precShows (c :+: d) = 'showInfix'' ":+:" 4 c d
+--     precShows (C a b) = 'showCon' \"C\" '@|' a '@|' b
+--     precShows (c :+: d) = 'showInfix'' \":+:\" 4 c d
 --     precShows (R {f1 = e, f2 = f}) =
---       'showRecord' "R" ("f1" '.=.' e '&|' "f2" '.=.' f)
+--       'showRecord' \"R\" (\"f1\" '.=.' e '&|' \"f2\" '.=.' f)
 -- @
 
 module Text.Show.Combinators
   ( module Text.Show
   , PrecShowS
+
+    -- * Simple constructors and applications
   , showCon
   , showApp
   , (@|)
+
+    -- * Infix constructors
   , showInfix
   , showInfix'
+
+    -- ** Combinators for associative operators
+    -- | Use with care, see 'showInfixl'.
+  , showInfixl
+  , showInfixl'
+  , showInfixr
+  , showInfixr'
+
+    -- * Records
   , ShowFields
   , showRecord
   , showField
@@ -46,6 +57,23 @@
 type PrecShowS = Int -> ShowS
 
 -- | Show a constructor.
+--
+-- Possible constructor names are:
+--
+-- - regular constructors (e.g., @\"Left\"@);
+-- - parenthesized infix constructors (e.g., @\"(:)\"@);
+-- - smart constructors, for abstract types (e.g., @\"Map.fromList\"@).
+--
+-- === __Example with smart constructor__
+--
+-- @
+-- instance (Show k, Show v) => Show (Map k v) where
+--   showsPrec = 'flip' precShows where
+--     precShows m = 'showCon' \"Map.fromList\" '@|' Map.toList m
+--
+-- -- Example output:
+-- -- > Map.fromList [(33, True), (55, False)]
+-- @
 showCon :: String -> PrecShowS
 showCon con _ = showString con
 
@@ -67,8 +95,7 @@
 
 -- | Show an applied infix operator with a given precedence.
 showInfix :: String -> Int -> PrecShowS -> PrecShowS -> PrecShowS
-showInfix op prec showX showY d = showParen (d > prec)
-  (showX (prec + 1) . showSpace . showString op . showSpace . showY (prec + 1))
+showInfix op prec = showInfix_ op prec (prec + 1) (prec + 1)
 
 -- | Show an applied infix operator with a given precedence.
 --
@@ -80,6 +107,69 @@
 showInfix' :: (Show a, Show b) => String -> Int -> a -> b -> PrecShowS
 showInfix' op prec x y = showInfix op prec (flip showsPrec x) (flip showsPrec y)
 
+-- | Show an applied infix operator which is left associative (@infixl@).
+-- Use with care.
+--
+-- This combinator assumes that, if there is another infix operator to the
+-- left, it is either left associative with the same precedence, or it has a
+-- different precedence.
+-- An expression containing two operators at the same level with different
+-- associativities is ambiguous.
+--
+-- By default, prefer 'showInfix' and 'showInfix''.
+showInfixl :: String -> Int -> PrecShowS -> PrecShowS -> PrecShowS
+showInfixl op prec = showInfix_ op prec prec (prec + 1)
+
+-- | Show an applied infix operator which is left associative (@infixl@).
+-- Use with care, see 'showInfixl'.
+--
+-- This is a shorthand for 'showInfixl' when the arguments types are instances
+-- of 'Show'.
+--
+-- By default, prefer 'showInfix' and 'showInfix''.
+showInfixl' :: (Show a, Show b) => String -> Int -> a -> b -> PrecShowS
+showInfixl' op prec x y = showInfixl op prec (flip showsPrec x) (flip showsPrec y)
+
+-- | Show an applied infix operator which is right associative (@infixr@).
+-- Use with care.
+--
+-- This combinator assumes that, if there is another infix operator to the
+-- right, it is either right associative with the same precedence, or it has a
+-- different precedence.
+-- An expression containing two operators at the same level with different
+-- associativities is ambiguous.
+--
+-- By default, prefer 'showInfix' and 'showInfix''.
+--
+-- === __Example usage__
+--
+-- @
+-- showList :: Show a => [a] -> PrecShowS
+-- showList [] = showCon "[]"
+-- showList (x : xs) = showInfixr ":" 5 (flip showsPrec x) (showList xs)
+--
+-- -- Example output:
+-- -- > 0 : 1 : 2 : 3 : []
+-- @
+showInfixr :: String -> Int -> PrecShowS -> PrecShowS -> PrecShowS
+showInfixr op prec = showInfix_ op prec (prec + 1) prec
+
+-- | Show an applied infix operator which is right associative (@infixr@).
+-- Use with care, see 'showInfixr'.
+--
+-- This is a shorthand for 'showInfixr' when the arguments types are instances
+-- of 'Show'.
+--
+-- By default, prefer 'showInfix' and 'showInfix''.
+showInfixr' :: (Show a, Show b) => String -> Int -> a -> b -> PrecShowS
+showInfixr' op prec x y = showInfixr op prec (flip showsPrec x) (flip showsPrec y)
+
+-- | An internal combinator for infix operators, to explicitly update the
+-- precedence levels on each side.
+showInfix_ :: String -> Int -> Int -> Int -> PrecShowS -> PrecShowS -> PrecShowS
+showInfix_ op prec precX precY showX showY d = showParen (d > prec)
+  (showX precX . showSpace . showString op . showSpace . showY precY)
+
 -- | Strings representing a set of record fields separated by commas.
 -- They can be constructed using ('.=.') and ('@|'), or using 'showField' and
 -- 'appendFields'.
@@ -103,7 +193,7 @@
 -- This is an infix shorthand for 'showField' when the value type is an
 -- instance of 'Show'.
 --
--- > field .=. x = showField field (flip showsPrec x)
+-- > field .=. x   =   showField field (flip showsPrec x)
 (.=.) :: Show a => String -> a -> ShowFields
 field .=. x = showField field (flip showsPrec x)
 
diff --git a/test/test.hs b/test/test.hs
--- a/test/test.hs
+++ b/test/test.hs
@@ -21,22 +21,39 @@
 _showsMyType' (R {f1 = e, f2 = f}) =
   showRecord "R" ("f1" .=. e &| "f2" .=. f)
 
+showL :: [Int] -> PrecShowS
+showL [] = showCon "[]"
+showL (x : xs) = showInfixr ":" 5 (flip showsPrec x) (showL xs)
+
+-- snoc lists
+showR :: [Int] -> PrecShowS
+showR [] = showCon "[]"
+showR (x : xs) = showInfixl ":" 5 (showR xs) (flip showsPrec x)
+
 check :: Show a => (a -> PrecShowS) -> a -> IO ()
-check show' x =
+check show' x = assertEqual s s'
+  where
+    s = show x
+    s' = show' x 0 ""
+
+assertEqual :: (Eq a, Show a) => a -> a -> IO ()
+assertEqual s s' =
   if s == s' then
     return ()
   else
     fail $ show (s, s')
-  where
-    s = show x
-    s' = show' x 0 ""
 
+unPS :: (a -> PrecShowS) -> a -> String
+unPS p x = p x 0 ""
+
 main :: IO ()
 main = do
   check smt1 (C () ())
   check smt2 (C (C () ()) (() :+: ()))
   check smt2 ((() :+: ()) :+: (() :+: ()))
   check smt2 (R (C () ()) (C () ()))
+  assertEqual (unPS showL [1,2,3]) "1 : 2 : 3 : []"
+  assertEqual (unPS showR [1,2,3]) "[] : 3 : 2 : 1"
   where
     smt1 = showsMyType (flip showsPrec)
     smt2 = showsMyType smt1