moved module and relicensed

Utility/PartialPrelude.hs

@@ -38,8 +38,9 @@ last = Prelude.last
 
 {- Attempts to read a value from a String.
  -
- - Unlike Text.Read.readMaybe, this ignores leading/trailing whitespace,
- - and throws away any trailing text after the part that can be read.
+ - Unlike Text.Read.readMaybe, this ignores some trailing text
+ - after the part that can be read. However, if the trailing text looks
+ - like another readable value, it fails.
  -}
 readish :: Read a => String -> Maybe a
 readish s = case reads s of

Utility/TimeStamp.hs

@@ -0,0 +1,39 @@
+{- timestamp parsing and formatting
+ -
+ - Copyright 2015-2016 Joey Hess <id@joeyh.name>
+ -
+ - License: BSD-2-clause
+ -}
+
+{-# LANGUAGE CPP #-}
+
+module Utility.TimeStamp where
+
+import Utility.PartialPrelude
+import Utility.Misc
+
+import Data.Time.Clock.POSIX
+import Data.Time
+import Data.Ratio
+#if ! MIN_VERSION_time(1,5,0)
+import System.Locale
+#endif
+
+{- Parses how POSIXTime shows itself: "1431286201.113452s"
+ - Also handles the format with no fractional seconds. -}
+parsePOSIXTime :: String -> Maybe POSIXTime
+parsePOSIXTime s = do
+	let (sn, sd) = separate (== '.') s
+	n <- readi sn
+	if null sd 
+		then return (fromIntegral n)
+		else do
+			d <- readi sd
+			let r = d % (10 ^ (length sd - 1))
+			return (fromIntegral n + fromRational r)
+  where
+	readi :: String -> Maybe Integer
+	readi = readish
+
+formatPOSIXTime :: String -> POSIXTime -> String
+formatPOSIXTime fmt t = formatTime defaultTimeLocale fmt (posixSecondsToUTCTime t)