examples: add GS8

servant-examples/getting-started/GS3.hs

@@ -14,13 +14,15 @@ import Servant
 data Position = Position
   { x :: Int
   , y :: Int
-  } deriving Generic
+  } deriving (Show, Generic)
 
+instance FromJSON Position
 instance ToJSON Position
 
 newtype HelloMessage = HelloMessage { msg :: String }
-  deriving Generic
+  deriving (Show, Generic)
 
+instance FromJSON HelloMessage
 instance ToJSON HelloMessage
 
 data ClientInfo = ClientInfo
@@ -28,17 +30,19 @@ data ClientInfo = ClientInfo
   , email :: String
   , age :: Int
   , interested_in :: [String]
-  } deriving Generic
+  } deriving (Show, Generic)
 
 instance FromJSON ClientInfo
+instance ToJSON ClientInfo
 
 data Email = Email
   { from :: String
   , to :: String
   , subject :: String
   , body :: String
-  } deriving Generic
+  } deriving (Show, Generic)
 
+instance FromJSON Email
 instance ToJSON Email
 
 emailForClient :: ClientInfo -> Email

servant-examples/getting-started/GS8.hs

@@ -0,0 +1,46 @@
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE TypeFamilies #-}
+{-# LANGUAGE TypeOperators #-}
+module GS8 where
+
+import Control.Monad.Trans.Either
+import Data.Aeson
+import Servant
+import Servant.Client
+
+import GS3
+
+position :: Int -- ^ value for "x"
+         -> Int -- ^ value for "y"
+         -> BaseUrl
+         -> EitherT ServantError IO Position
+
+hello :: Maybe String -- ^ an optional value for "name"
+      -> BaseUrl
+      -> EitherT ServantError IO HelloMessage
+
+marketing :: ClientInfo -- ^ value for the request body
+          -> BaseUrl
+          -> EitherT ServantError IO Email
+
+position :<|> hello :<|> marketing = client api 
+
+baseUrl :: BaseUrl
+baseUrl = BaseUrl Http "localhost" 8081
+
+queries :: EitherT ServantError IO (Position, HelloMessage, Email)
+queries = do
+  pos <- position 10 10 baseUrl
+  msg <- hello (Just "servant") baseUrl
+  em  <- marketing (ClientInfo "Alp" "alp@foo.com" 26 ["haskell", "mathematics"]) baseUrl
+  return (pos, msg, em)
+
+run :: IO ()
+run = do
+  res <- runEitherT queries
+  case res of
+    Left err -> putStrLn $ "Error: " ++ show err
+    Right (pos, msg, em) -> do
+      print pos
+      print msg
+      print em

servant-examples/getting-started/getting-started.hs

@@ -19,6 +19,7 @@ app n = case n of
   "5" -> Just GS5.app
   "6" -> Just GS6.app
   "7" -> Just GS7.app
+  "8" -> Just GS3.app
   _   -> Nothing
 
 main :: IO ()

servant-examples/getting-started/gs8-main.hs

@@ -0,0 +1,4 @@
+import GS8
+
+main :: IO ()
+main = run

servant-examples/servant-examples.cabal

@@ -32,6 +32,19 @@ executable getting-started
   hs-source-dirs: getting-started
   default-language: Haskell2010
 
+executable gs8-main
+  main-is: gs8-main.hs
+  hs-source-dirs: getting-started
+  default-language: Haskell2010
+  build-depends:
+      aeson
+    , base
+    , either
+    , servant
+    , servant-client
+    , servant-server
+    , wai
+
 executable hackage
   main-is:             hackage.hs
   build-depends: