git-annex/Utility/HumanTime.hs
2012-12-13 00:24:19 -04:00

26 lines
664 B
Haskell

{- Time for humans.
-
- Copyright 2012 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Utility.HumanTime where
import Utility.PartialPrelude
import Data.Time.Clock.POSIX (POSIXTime)
{- Parses a human-input time duration, of the form "5h" or "1m". -}
parseDuration :: String -> Maybe POSIXTime
parseDuration s = do
num <- readish s :: Maybe Integer
units <- findUnits =<< lastMaybe s
return $ fromIntegral num * units
where
findUnits 's' = Just 1
findUnits 'm' = Just 60
findUnits 'h' = Just $ 60 * 60
findUnits 'd' = Just $ 60 * 60 * 24
findUnits 'y' = Just $ 60 * 60 * 24 * 365
findUnits _ = Nothing