Upload current attempts

scratchpads/csv.hs

@@ -0,0 +1,44 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE TemplateHaskell #-}
+-- This requires my custom BootTidal.hs
+
+import Prelude hiding (filter)
+import qualified Data.ByteString.Lazy as BL
+import Data.Csv -- this is from the Cassava library
+import qualified Data.Vector as V
+-- import System.Directory (doesFileExist)
+-- import Text.Printf
+-- import Control.Monad (forM_)
+import GHC.IO.Exception
+import Control.Exception (try)
+
+
+data TimestampedDatum = TimestampedDatum {
+    timestamp :: String,
+    datum :: Float
+} deriving Show
+
+dataPath = "../data/weather/balcony_temperature.csv"
+
+instance FromNamedRecord TimestampedDatum where
+  parseNamedRecord r = 
+    TimestampedDatum 
+    <$> r .: "time" 
+    <*> r .: "C.value"
+
+
+type ErrorMsg = String
+type CsvData = (Header, V.Vector TimestampedDatum)
+
+parseCsv :: FilePath -> IO (Either ErrorMsg CsvData)
+parseCsv filePath = do
+  result <- try $ BL.readFile filePath
+  return $ case result of
+             Left (exception :: IOException) -> Left $ show exception
+             Right contents -> decodeByName contents
+
+getList :: CsvData -> V.Vector TimestampedDatum
+getList = snd
+
+-- getValue :: TimestampedDatum -> Float
+-- getValue = datum