очень меееееедлееееенно

parsing-kirill.hs

-- Main.hs
module Main where

import Lib
import System.Clock

main :: IO ()
main = do
  start <- getTime Monotonic
  parseAndWrite source1 output
  end <- getTime Monotonic
  print $ end `diffTimeSpec` start
  where
    source1 = "/home/almakarov/Documents/EMHIRES_PVGIS_TSh_CF_n2_19862015.csv"
    source11 = "/home/almakarov/Documents/EMHIRES_PVGIS_TSh_CF_n2_19862015(1).csv"
    source2 = "/home/odomontois/Documents/EMHIRESPV_TSh_CF_Country_19862015.csv"
    output = "/home/almakarov/Documents/Output.txt"

-- Lib.hs
{-# LANGUAGE BlockArguments #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE NumericUnderscores #-}
module Lib
    ( parseAndWrite
    ) where

import           Data.Function ((&))
import qualified Data.ByteString as BS
import qualified Data.Text as T
import           Streamly
import qualified Streamly.Prelude as S
import qualified Streamly.FileSystem.Handle as S
import qualified Streamly.Data.Unicode.Stream as S
import qualified Streamly.Memory.Array as SA
import qualified Streamly.Data.Fold as SF
import           System.IO (withFile, IOMode(..))

parseAndWrite ifp ofp =
  withFile ifp ReadWriteMode \iHandle ->
  withFile ofp ReadWriteMode \oHandle ->
    S.unfold S.readWithBufferOf (500, iHandle)
      & S.decodeUtf8
      & lines
      >>= S.fromList . fmap (<> "\n") . T.split (== ',')
      >>= S.fromList . T.unpack
      & S.encodeUtf8
      & S.scan (S.writeWithBufferOf 10_000 oHandle)
      & serially
      & S.drain
  where
    lines = S.splitOn (== '\n') (T.pack <$> SF.toList)