From c122a906639fe528a0b5a6108ba0ed6d245d81d6 Mon Sep 17 00:00:00 2001
From: Sibi <sibi@psibi.in>
Date: Fri, 17 Jul 2015 00:50:10 +0530
Subject: [PATCH] Haskell code.

---
 README.md          |  9 ++++++++
 Server.hs          | 54 ++++++++++++++++++++++++++++++++++++++++++++++
 react-scotty.cabal | 28 ++++++++++++++++++++++++
 3 files changed, 91 insertions(+)
 create mode 100644 Server.hs
 create mode 100644 react-scotty.cabal

diff --git a/README.md b/README.md
index f8aa5bc7..80942982 100644
--- a/README.md
+++ b/README.md
@@ -22,6 +22,15 @@ pip install -r requirements.txt
 python server.py
 ```
 
+### Haskell
+
+```sh
+cabal sandbox init
+cabal install --only-dependencies
+ghc Server.hs
+./Server
+```
+
 ### Ruby
 ```sh
 ruby server.rb
diff --git a/Server.hs b/Server.hs
new file mode 100644
index 00000000..de416d7d
--- /dev/null
+++ b/Server.hs
@@ -0,0 +1,54 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Main (main) where
+
+import Web.Scotty
+
+import Control.Monad (mzero)
+import Control.Monad.Trans
+import Network.Wai.Middleware.Static
+import Network.Wai.Middleware.RequestLogger (logStdoutDev)
+import Data.ByteString.Lazy (readFile, writeFile, fromStrict)
+import qualified Data.ByteString as BS (readFile)
+import Prelude hiding (readFile, writeFile)
+import Data.Aeson hiding (json)
+import Data.Text
+import Data.Maybe (fromJust)
+
+data Comment = Comment {
+      commentText :: Text,
+      author :: Text
+    } deriving (Eq, Show, Ord)
+
+instance FromJSON Comment where
+    parseJSON (Object v) = Comment <$>
+                           v .: "text" <*>
+                           v .: "author"
+    parseJSON _ = mzero
+
+instance ToJSON Comment where
+     toJSON (Comment ctext author) = object ["text" .= ctext, "author" .= author]
+
+
+main :: IO ()
+main = scotty 3000 $ do
+         
+    middleware $ staticPolicy (noDots >-> addBase "public")
+    middleware logStdoutDev
+
+    get "/" $ file "./public/index.html"
+
+    get "/comments.json" $ do
+      comments <- liftIO $ readFile "comments.json"
+      json $ fromJust $ (decode comments :: Maybe [Comment])
+           
+    post "/comments.json" $ do
+      comments <- liftIO $ BS.readFile "comments.json"
+      let jsonComments = fromJust $ (decode $ fromStrict comments :: Maybe [Comment])
+      author <- param "author"
+      comment <- param "text"
+      let allComments = jsonComments ++ [Comment comment author]
+      liftIO $ writeFile "comments.json" (encode allComments)
+      json allComments
+
+
diff --git a/react-scotty.cabal b/react-scotty.cabal
new file mode 100644
index 00000000..a3024211
--- /dev/null
+++ b/react-scotty.cabal
@@ -0,0 +1,28 @@
+-- Initial react-scotty.cabal generated by cabal init.  For further 
+-- documentation, see http://haskell.org/cabal/users-guide/
+
+name:                react-scotty
+version:             0.1.0.0
+synopsis:            React Haskell code with Scotty
+-- description:         
+license:             GPL-2
+license-file:        LICENSE
+author:              Sibi
+maintainer:          sibi@psibi.in
+-- copyright:           
+category:            Web
+build-type:          Simple
+-- extra-source-files:  
+cabal-version:       >=1.10
+
+executable react-scotty
+  main-is:             Server.hs
+  -- other-modules:       
+  -- other-extensions:    
+  build-depends:       base >=4.8 && <4.9,
+                       scotty, wai-extra,
+                       mtl, text, aeson, 
+                       bytestring, 
+                       wai-middleware-static
+  -- hs-source-dirs:      
+  default-language:    Haskell2010