84 lines
2.2 KiB
Haskell
84 lines
2.2 KiB
Haskell
{-# LANGUAGE DataKinds #-}
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{-# LANGUAGE DeriveGeneric #-}
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{-# LANGUAGE TypeOperators #-}
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{-# LANGUAGE OverloadedStrings #-}
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import Control.Applicative
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import Control.Monad
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import Control.Monad.IO.Class
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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 (Text)
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import GHC.Generics
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import Servant.API
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import Servant.Client
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import qualified Data.Text as T
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import qualified Data.Text.IO as T
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type HackageAPI =
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"users" :> Get '[JSON] [UserSummary]
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:<|> "user" :> Capture "username" Username :> Get '[JSON] UserDetailed
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:<|> "packages" :> Get '[JSON] [Package]
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type Username = Text
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data UserSummary = UserSummary
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{ summaryUsername :: Username
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, summaryUserid :: Int
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} deriving (Eq, Show)
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instance FromJSON UserSummary where
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parseJSON (Object o) =
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UserSummary <$> o .: "username"
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<*> o .: "userid"
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parseJSON _ = mzero
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type Group = Text
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data UserDetailed = UserDetailed
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{ username :: Username
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, userid :: Int
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, groups :: [Group]
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} deriving (Eq, Show, Generic)
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instance FromJSON UserDetailed
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newtype Package = Package { packageName :: Text }
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deriving (Eq, Show, Generic)
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instance FromJSON Package
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hackageAPI :: Proxy HackageAPI
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hackageAPI = Proxy
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getUsers :: BaseUrl -> EitherT ServantError IO [UserSummary]
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getUser :: Username -> BaseUrl -> EitherT ServantError IO UserDetailed
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getPackages :: BaseUrl -> EitherT ServantError IO [Package]
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getUsers :<|> getUser :<|> getPackages = client hackageAPI
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run :: (BaseUrl -> r) -> r
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run f = f (BaseUrl Http "hackage.haskell.org" 80)
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main :: IO ()
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main = print =<< uselessNumbers
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uselessNumbers :: IO (Either ServantError ())
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uselessNumbers = runEitherT $ do
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users <- run getUsers
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liftIO . putStrLn $ show (length users) ++ " users"
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user <- liftIO $ do
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putStrLn "Enter a valid hackage username"
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T.getLine
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userDetailed <- run (getUser user)
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liftIO . T.putStrLn $ user <> " maintains " <> T.pack (show (length $ groups userDetailed)) <> " packages"
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packages <- run getPackages
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let monadPackages = filter (isMonadPackage . packageName) packages
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liftIO . putStrLn $ show (length monadPackages) ++ " monad packages"
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where isMonadPackage = T.isInfixOf "monad"
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