Haskell Data Analysis

process.lhs

> {-# LANGUAGE DeriveGeneric #-}

> import Data.Csv (decodeByName, FromNamedRecord, ToNamedRecord, DefaultOrdered, Header)
> import Data.Text
> import Data.Text.Encoding (encodeUtf8)
> import Data.Text.IO (putStrLn)
> import Data.Vector
> import Data.Set
> import Prelude hiding (readFile)
> import Data.ByteString.Lazy (readFile)
> import GHC.Generics

> data SeqEcoRecord = SeqEcoRecord { id :: !Int,
>                                    datetime_sys :: !Text,
>                                    eventname :: !Text,
>                                    datetime :: !Text,
>                                    username :: !Text,
>                                    key :: !Text,
>                                    value :: !Text,
>                                    raw :: !Text }
>                   deriving (Generic, Show)

> instance FromNamedRecord SeqEcoRecord
> instance ToNamedRecord SeqEcoRecord
> instance DefaultOrdered SeqEcoRecord

> mapIO :: (a -> IO ()) -> [a] -> IO ()
> mapIO f xs = if Prelude.null xs then return () else do
>   f (Prelude.head xs)
>   mapIO f (Prelude.tail xs)

`allKeys` fetches all the keys that occured in the original sequence record.

> allKeys :: Vector SeqEcoRecord -> Set Text
> allKeys a = Data.Set.fromList $ Data.Vector.toList $ Data.Vector.map key a

Here's the result of all keys:

QA_section_started
QA_section_started_at_entry_point
localStorage_error
next_button_clicked
question_「各盡所能，各取所需」是個很棒的念頭
question_人民根本上是通過階級而非國籍來劃分的
question_以資本生財的人對社會的貢獻比不上靠勞動賺錢的人
question_企業不會自覺保護環境，因此需要規章來規範它們
question_保護主義對貿易來說有時候是必須的
question_公司為它的股東賺取利潤就是它僅有的社會職責
question_土地完全可以作為商品在市場上自由買買
question_土地完全可以作為商品在市場上自由買賣
question_在重大工程的決策中，個人利益應為社會整體利益讓路
question_如果食品價格過高，政府應當干預
question_學歷
question_對富人徵收的稅太高了
question_市場越自由，人民越自由
question_年齡
question_性別
question_控制通貨膨脹比控制失業更重要
question_改善低收入人士生活的首要手段是政府給予財政補貼和扶持
question_政府應對商品的出入境設限，以首先滿足境內需求
question_政府應該懲罰誤導公眾的商業行為
question_政府應該為最低工資立法
question_教育應當儘可能公營
question_社會中一些基本事物如飲用水不應該成為貨架上的商品
question_試圖控制房地產價格的行為會破壞經濟發展
question_那些付得起錢的人理應有權獲得更好的醫療
referrer
render
share_button_click
total_score_before_normalization
url
userAgent

So based on those keys, we define UserRecord:

> data UserRecord = UserRecord 

> vectorMain :: Vector SeqEcoRecord -> IO ()
> vectorMain v = mapIO Data.Text.IO.putStrLn $ Data.Set.toList $ allKeys v

> main :: IO ()
> main = do
>   s <- readFile "ecocompass.csv"
>   let d = decodeByName s :: Either String (Header, Vector SeqEcoRecord)
>   case d of
>     Left x -> print x
>     Right (h, r) -> vectorMain r