haskell/Readline.hs

   1 module Readline
   2 ( addHistory, readline, load_history )
   3 where
   4
   5 -- Pick one of these:
   6 -- GPL license
   7 import qualified System.Console.Readline as RL
   8 -- BSD license
   9 --import qualified System.Console.Editline.Readline as RL
  10
  11 import Control.Monad (when)
  12 import System.Directory (getHomeDirectory, doesFileExist)
  13 import System.IO.Error (tryIOError)
  14
  15 history_file :: IO String
  16 history_file = do
  17     home <- getHomeDirectory
  18     return $ home ++ "/.mal-history"
  19
  20 load_history :: IO ()
  21 load_history = do
  22     hfile <- history_file
  23     fileExists <- doesFileExist hfile
  24     when fileExists $ do
  25         content <- readFile hfile
  26         mapM_ RL.addHistory (lines content)
  27
  28 readline :: String -> IO (Maybe String)
  29 readline = RL.readline
  30
  31 addHistory :: String -> IO ()
  32 addHistory line = do
  33     hfile <- history_file
  34     _ <- tryIOError (appendFile hfile (line ++ "\n"))
  35     RL.addHistory line