Generates a json file describing the directory structure

gen_files_json.hs

module Main where

import System.Directory (getDirectoryContents)
import Control.Monad (forM_)
import Data.Functor ((<$>))
import System.Posix.Files (getSymbolicLinkStatus, isDirectory)

withIsLast :: [a] -> [(a, Bool)]
withIsLast [] = []
withIsLast [x] = [(x, True)]
withIsLast (x:xs) = (x, False) : withIsLast xs

printFile :: String -> String -> Bool -> IO ()
printFile top d isLast = do
  let path = top ++ "/" ++ d
      quotedPath = "\"" ++ d ++ "\""
  s <- getSymbolicLinkStatus path
  putStr $ quotedPath ++ ": "
  if isDirectory s
    then do putStrLn "{"
            traverseDir path
            putStr "}"
    else putStr "null"
  putStrLn $ if isLast then "" else ","
           
traverseDir :: FilePath -> IO ()
traverseDir top = do
  ds <- filter (\n -> n /= "." && n /= "..") <$> getDirectoryContents top
  forM_ (withIsLast ds) $ \(d, isLast) -> printFile top d isLast

main :: IO ()
main = do
  putStrLn "{"
  traverseDir "."
  putStrLn "}"