50 lines
1.1 KiB
Haskell
50 lines
1.1 KiB
Haskell
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{-# LANGUAGE DataKinds #-}
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{-# LANGUAGE TypeFamilies #-}
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{-# LANGUAGE DeriveGeneric #-}
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{-# LANGUAGE TypeOperators #-}
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module GS2 where
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import Data.Aeson
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import Data.Time.Calendar
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import GHC.Generics
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import Network.Wai
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import Servant
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data User = User
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{ name :: String
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, age :: Int
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, email :: String
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, registration_date :: Day
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} deriving (Eq, Show, Generic)
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-- orphan ToJSON instance for Day. necessary to derive one for User
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instance ToJSON Day where
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-- display a day in YYYY-mm-dd format
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toJSON d = toJSON (showGregorian d)
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instance ToJSON User
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type UserAPI = "users" :> Get '[JSON] [User]
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:<|> "albert" :> Get '[JSON] User
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:<|> "isaac" :> Get '[JSON] User
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isaac :: User
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isaac = User "Isaac Newton" 372 "isaac@newton.co.uk" (fromGregorian 1683 3 1)
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albert :: User
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albert = User "Albert Einstein" 136 "ae@mc2.org" (fromGregorian 1905 12 1)
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users :: [User]
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users = [isaac, albert]
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userAPI :: Proxy UserAPI
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userAPI = Proxy
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server :: Server UserAPI
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server = return users
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:<|> return albert
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:<|> return isaac
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app :: Application
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app = serve userAPI server
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