96 lines
2.4 KiB
Haskell
96 lines
2.4 KiB
Haskell
{-# LANGUAGE DataKinds #-}
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{-# LANGUAGE PolyKinds #-}
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{-# LANGUAGE TypeFamilies #-}
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{-# LANGUAGE DeriveGeneric #-}
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{-# LANGUAGE TypeOperators #-}
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{-# LANGUAGE FlexibleInstances #-}
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{-# LANGUAGE OverloadedStrings #-}
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{-# OPTIONS_GHC -fno-warn-orphans #-}
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import Control.Concurrent (forkIO, killThread)
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import Control.Monad.Trans.Either
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import Data.Aeson
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import Data.Monoid
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import Data.Proxy
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import Data.Text
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import GHC.Generics
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import Network.URI
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import Network.Wai
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import Network.Wai.Handler.Warp
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import Servant.API
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import Servant.Client
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import Servant.Docs
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import Servant.Server
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-- * Example
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data Greet = Greet { _msg :: Text }
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deriving (Generic, Show)
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instance FromJSON Greet
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instance ToJSON Greet
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instance ToCapture (Capture "name" Text) where
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toCapture _ = DocCapture "name" "name of the person to greet"
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instance ToParam (GetParam "capital" Bool) where
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toParam _ =
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DocGetParam "capital"
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["true", "false"]
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"Get the greeting message in uppercase (true) or not (false). Default is false."
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instance ToSample Greet where
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toSample Proxy = Just (encode g)
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where g = Greet "Hello, haskeller!"
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-- API specification
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type TestApi =
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"hello" :> Capture "name" Text :> GetParam "capital" Bool :> Get Greet
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:<|> "greet" :> RQBody Greet :> Post Greet
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testApi :: Proxy TestApi
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testApi = Proxy
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-- Server-side handlers
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server :: Server TestApi
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server = hello :<|> greet
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where hello name Nothing = hello name (Just False)
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hello name (Just False) = return . Greet $ "Hello, " <> name
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hello name (Just True) = return . Greet . toUpper $ "Hello, " <> name
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greet = return
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-- Client-side query functions
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clientApi :: Client TestApi
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clientApi = client testApi
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getGreet :: Text -> Maybe Bool -> URI -> EitherT String IO Greet
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postGreet :: Greet -> URI -> EitherT String IO Greet
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getGreet :<|> postGreet = clientApi
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-- Turn the server into a WAI app
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test :: Application
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test = serve testApi server
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docsGreet :: API
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docsGreet = docs testApi
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-- Run the server
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runTestServer :: Port -> IO ()
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runTestServer port = run port test
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-- Run some queries against the server
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main :: IO ()
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main = do
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tid <- forkIO $ runTestServer 8001
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let Just uri = parseURI "http://localhost:8001"
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print =<< runEitherT (getGreet "alp" (Just True) uri)
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print =<< runEitherT (getGreet "alp" (Just False) uri)
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let g = Greet "yo"
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print =<< runEitherT (postGreet g uri)
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killThread tid
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putStrLn "\n---------\n"
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printMarkdown docsGreet
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