diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -6,6 +6,8 @@
 * remove head newline if exist
 * remove one space from '|', space, space, ..., ']'
 
+## short examples
+
 ```hs
 hello = [nowdoc|
 abc
@@ -46,4 +48,51 @@
 
 ```hs
 hello = "hello |]\nworld| ]\n! |  ]"
+```
+
+## run perl
+
+```hs
+{-# LANGUAGE QuasiQuotes #-}
+
+import System.Process
+import Text.Nowdoc
+
+main :: IO ()
+main = () <$ rawSystem "perl" ["-e", [nowdoc|
+use strict;
+use warnings;
+
+my $hello = "Hello, world!\n";
+print $hello;
+|]]
+```
+
+## ASCII art
+
+```hs
+{-# LANGUAGE QuasiQuotes #-}
+
+import Text.Nowdoc
+
+main :: IO ()
+main = putStr [nowdoc|
+            ______             
+       .d$$$******$$$$c.       
+    .d$P"            "$$c      
+   $$$$$.           .$$$*$.    
+ .$$ 4$L*$$.     .$$Pd$  '$b   
+ $F   *$. "$$e.e$$" 4$F   ^$b  
+d$     $$   z$$$e   $$     '$. 
+$P     `$L$$P` `"$$d$"      $$ 
+$$     e$$F       4$$b.     $$ 
+$b  .$$" $$      .$$ "4$b.  $$ 
+$$e$P"    $b     d$`    "$$c$F 
+'$P$$$$$$$$$$$$$$$$$$$$$$$$$$  
+ "$c.      4$.  $$       .$$   
+  ^$$.      $$ d$"      d$P    
+    "$$c.   `$b$F    .d$P"     
+      `4$$$c.$$$..e$$P"        
+          `^^^^^^^`
+|]
 ```
diff --git a/nowdoc.cabal b/nowdoc.cabal
--- a/nowdoc.cabal
+++ b/nowdoc.cabal
@@ -2,12 +2,12 @@
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 5c79bb879133786755fd90f6d2d66bc8d423fc9d44335dafa3cdaa458f0fc7e2
+-- hash: 210f2844c035c43c8f37a0625f4be9e91610d28eaba8a46bec9f0880222815ae
 
 name:           nowdoc
-version:        0.1.0.3
+version:        0.1.0.4
 synopsis:       Here document without variable expansion like PHP Nowdoc
-description:    Please see the README on GitHub
+description:    Please see the README on GitHub at <https://github.com/YoshikuniJujo/nowdoc#readme>
 category:       Text
 homepage:       https://github.com/YoshikuniJujo/nowdoc#readme
 bug-reports:    https://github.com/YoshikuniJujo/nowdoc/issues
diff --git a/src/Text/Nowdoc.hs b/src/Text/Nowdoc.hs
--- a/src/Text/Nowdoc.hs
+++ b/src/Text/Nowdoc.hs
@@ -1,26 +1,17 @@
+{-# LANGUAGE LambdaCase #-}
 {-# OPTIONS_GHC -Wall -fno-warn-tabs #-}
 
 module Text.Nowdoc (nowdoc) where
 
-import Language.Haskell.TH (litE, stringL)
+import Language.Haskell.TH (stringE)
 import Language.Haskell.TH.Quote (QuasiQuoter(..))
 
 nowdoc :: QuasiQuoter
 nowdoc = QuasiQuoter {
-	quoteExp = litE . stringL . unescape . dropHeadNewline,
-	quotePat = const . error $ errorString "a pattern",
-	quoteType = const . error $ errorString "a type",
-	quoteDec = const . error $ errorString "a declaration"
-	}
-
-errorString :: String -> String
-errorString ctx =
-	"You have used the `nowdoc' QuasiQoter in " ++ ctx ++
-	" context; you must only use it in an expression context"
-
-dropHeadNewline :: String -> String
-dropHeadNewline ('\n' : cs) = cs
-dropHeadNewline cs = cs
+	quoteExp = stringE . unescape . \case '\n' : cs -> cs; cs -> cs,
+	quotePat = const $ err "pattern",
+	quoteType = const $ err "type",
+	quoteDec = const $ err "declaration" }
 
 unescape :: String -> String
 unescape ('|' : cs) = case span (== ' ') cs of
@@ -28,3 +19,8 @@
 	(ss, cs') -> '|' : ss ++ unescape cs'
 unescape (c : cs) = c : unescape cs
 unescape "" = ""
+
+err :: String -> a
+err ctx = error $
+	"You have used the `nowdoc' QuasiQoter in a " ++ ctx ++
+	" context; you must only use it in an expression context"