Added mkcsv.

Much much faster than mkcsv.py.

pl2-3/mkcsv.py

@@ -7,7 +7,7 @@
 
 PARSER = argparse.ArgumentParser()
 PARSER.add_argument('--attr-len', '-a', metavar='SIZE', type=int,
-                    dest='attr')
+                    dest='attr', default=9)
 PARSER.add_argument('tuples', metavar='COUNT', type=int)
 PARSER.add_argument('file', metavar='FILE', type=argparse.FileType('w'))
 args = PARSER.parse_args()

pl4/.gitignore

@@ -10,3 +10,5 @@ csv2leveldb
 query_leveldb
 csv2idx_leveldb
 query_idx_leveldb
+*.hi
+mkcsv

pl4/mkcsv.hs

@@ -0,0 +1,48 @@
+{-# LANGUAGE OverloadedStrings   #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+module Main (main) where
+
+import           Control.Monad         (void, when)
+import           Data.ByteString.Char8 (ByteString)
+import qualified Data.ByteString.Char8 as BS
+import           System.Environment    (getArgs, getProgName)
+import           System.Exit           (exitFailure)
+import           System.Random
+
+main :: IO ()
+main = do
+    args <- getArgs
+
+    when (null args) $ do
+        prog <- getProgName
+        putStrLn $ "USAGE: " ++ prog ++ " <tuple count>"
+        exitFailure
+    let tupleCount = read (head args) :: Integer
+    void $ times tupleCount $
+        generateTuple 100 >>= BS.putStrLn . BS.intercalate ","
+
+    return ()
+
+choices :: ByteString
+choices = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+
+choice :: RandomGen g => ByteString -> g -> (Char, g)
+choice l g = let (i, g') = randomR (0, BS.length l -  1) g
+             in (l `BS.index` i, g')
+
+randomByteString :: forall g. RandomGen g => Int -> g -> (ByteString, g)
+randomByteString len rand =
+    let (bs, Just rand') = BS.unfoldrN len step rand
+    in (bs, rand')
+  where
+    step :: g -> Maybe (Char, g)
+    step g = Just $ choice choices g
+
+generateAttr :: Int -> IO ByteString
+generateAttr len = getStdRandom (randomByteString len)
+
+generateTuple :: Integer -> IO [ByteString]
+generateTuple count = times count $ generateAttr 9
+
+times :: Monad m => Integer -> m a -> m [a]
+times c m = mapM (const m) [1..c]