Mundanities.hs

   1 -- This file is part of Diohsc
   2 -- Copyright (C) 2020 Martin Bays <mbays@sdf.org>
   3 --
   4 -- This program is free software: you can redistribute it and/or modify
   5 -- it under the terms of version 3 of the GNU General Public License as
   6 -- published by the Free Software Foundation, or any later version.
   7 --
   8 -- You should have received a copy of the GNU General Public License
   9 -- along with this program.  If not, see http://www.gnu.org/licenses/.
  10
  11 {-# LANGUAGE Safe #-}
  12
  13 module Mundanities where
  14
  15 import           Control.Applicative     (Alternative, empty)
  16 import           Control.Monad.Catch     (MonadMask, handle)
  17 import           Control.Monad.IO.Class  (MonadIO, liftIO)
  18 import           Safe
  19 import           System.Directory
  20 import           System.FilePath
  21
  22 import qualified Data.ByteString         as BS
  23 import qualified Data.ByteString.Lazy    as BL
  24 import qualified Data.Text               as TS
  25 import qualified Data.Text.IO            as TS
  26 import qualified Data.Text.Lazy          as T
  27 import qualified Data.Text.Lazy.Encoding as T
  28
  29 mkdirhierto :: FilePath -> IO ()
  30 mkdirhierto = mkdirhier . takeDirectory
  31 mkdirhier :: FilePath -> IO ()
  32 mkdirhier = createDirectoryIfMissing True
  33
  34 -- |returns true iff path is contained within the directory dir
  35 isSubPath :: FilePath -> FilePath -> IO Bool
  36 isSubPath dir path = isRelative . makeRelative dir <$> canonicalizePath path
  37
  38 ignoreIOErr :: (MonadIO m, MonadMask m, Monoid a) => m a -> m a
  39 ignoreIOErr = handle ((\_ -> return mempty) :: (Monad m, Monoid a) => IOError -> m a)
  40
  41 warnIOErr :: (MonadIO m, MonadMask m, Monoid a) => m a -> m a
  42 warnIOErr = handle ((\e -> liftIO (print e) >> return mempty) :: (MonadIO m, Monoid a) => IOError -> m a)
  43
  44 ignoreIOErrAlt :: (MonadIO m, MonadMask m, Alternative f) => m (f a) -> m (f a)
  45 ignoreIOErrAlt = handle ((\_ -> return empty) :: (Monad m, Alternative f) => IOError -> m (f a))
  46
  47 warnIOErrAlt :: (MonadIO m, MonadMask m, Alternative f) => m (f a) -> m (f a)
  48 warnIOErrAlt = handle ((\e -> liftIO (print e) >> return empty) :: (MonadIO m, Alternative f) => IOError -> m (f a))
  49
  50 readFileLines :: FilePath -> IO [T.Text]
  51 readFileLines path = ignoreIOErr $
  52     map T.strip . T.lines . T.decodeUtf8 . BL.fromStrict <$> BS.readFile path
  53
  54 writeReadFile :: (Show a) => FilePath -> a -> IO ()
  55 writeReadFile path = BL.writeFile path . T.encodeUtf8 . T.pack . show
  56
  57 readReadFile :: (Read a) => FilePath -> IO (Maybe a)
  58 readReadFile path = ignoreIOErrAlt $
  59     readMay . T.unpack . T.decodeUtf8 . BL.fromStrict <$> BS.readFile path
  60
  61 -- delete all but last n lines of file
  62 truncateToEnd :: Int -> FilePath -> IO ()
  63 truncateToEnd n path =
  64     TS.readFile path >>= TS.writeFile path . TS.unlines . dropAllBut n . TS.lines
  65     where dropAllBut m as = drop (length as - m) as