Filter the files in a directory where the names of the files are numeric strings and create a directory for each file filtered, naming the directories the same with the file, moving the file into the folder and changing the name of the file to "index.svg"

module Main where
import System.Directory
import System.FilePath
import Control.Exception
import Data.List

main = do
  createDirectories
  putStrLn "Done"

createDirectories :: IO ()
createDirectories = do
  curDir <- getCurrentDirectory
  files <- (listDirectory curDir)
  let
    numFiles = filter isNumber files
    numDirs = map (curDir </>) numFiles
    zipped = zip numFiles numDirs
    createDirAndMoveFile (file, dir) = do
      createDirectory dir
      renameFile file (dir </> "index.svg")
  mapM_ createDirAndMoveFile zipped

isNumber :: String -> Bool
isNumber s = case reads s :: [(Integer, String)] of
  [(_, "")] -> True
  _         -> False