{- This module is part of Chatty. Copyleft (c) 2014 Marvin Cohrs All wrongs reversed. Sharing is an act of love, not crime. Please share Antisplice with everyone you like. Chatty is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. Chatty is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details. You should have received a copy of the GNU Affero General Public License along with Chatty. If not, see <http://www.gnu.org/licenses/>. -} -- | Provides typeclasses for clocks and randomizer environments module System.Chatty.Misc where import Data.Time.Clock import Data.Time.Calendar import System.Random -- | Typeclass for all monads that know the time class (Functor m,Monad m) => MonadClock m where -- | Get UTC Time mutctime :: m UTCTime -- | Get timestamp, guaranteed to grow mgetstamp :: m NominalDiffTime mgetstamp = fmap (flip diffUTCTime (UTCTime (fromGregorian 1970 1 1) (secondsToDiffTime 0))) mutctime instance MonadClock IO where mutctime = getCurrentTime -- | Typeclass for all monads that may provide random numbers class Monad m => MonadRandom m where -- | Get a single random number mrandom :: Random r => m r -- | Get a single random number in the given range mrandomR :: Random r => (r,r) -> m r instance MonadRandom IO where mrandom = randomIO mrandomR rs = randomRIO rs