htalkat-0.1.1: Mundanities.hs

-- This file is part of htalkat
-- Copyright (C) 2021 Martin Bays <mbays@sdf.org>
--
-- This program is free software: you can redistribute it and/or modify
-- it under the terms of version 3 of the GNU General Public License as
-- published by the Free Software Foundation, or any later version.
--
-- You should have received a copy of the GNU General Public License
-- along with this program.  If not, see http://www.gnu.org/licenses/.

{-# LANGUAGE Safe #-}

module Mundanities where

import           Control.Applicative    (Alternative, empty)
import           Control.Monad.Catch    (MonadMask, handle)
import           Control.Monad.IO.Class (MonadIO, liftIO)
import           System.Directory
import           System.FilePath

-- |returns true iff path is contained within the directory dir
isSubPath :: FilePath -> FilePath -> IO Bool
isSubPath dir path = isRelative . makeRelative dir <$> canonicalizePath path

ignoreIOErr :: (MonadIO m, MonadMask m, Monoid a) => m a -> m a
ignoreIOErr = handle ((\_ -> return mempty) :: (Monad m, Monoid a) => IOError -> m a)

warnIOErr :: (MonadIO m, MonadMask m, Monoid a) => m a -> m a
warnIOErr = handle ((\e -> liftIO (print e) >> return mempty) :: (MonadIO m, Monoid a) => IOError -> m a)

ignoreIOErrAlt :: (MonadIO m, MonadMask m, Alternative f) => m (f a) -> m (f a)
ignoreIOErrAlt = handle ((\_ -> return empty) :: (Monad m, Alternative f) => IOError -> m (f a))

warnIOErrAlt :: (MonadIO m, MonadMask m, Alternative f) => m (f a) -> m (f a)
warnIOErrAlt = handle ((\e -> liftIO (print e) >> return empty) :: (MonadIO m, Alternative f) => IOError -> m (f a))