
Now, when I have managed to convert UTCTime to seconds (see code below) I
got stuck trying to convert from UTCTime to CalendarTime, how to do this?
import Data.Time.Format
import Data.Time.Clock
import Locale
import Data.Maybe
import Data.Time.Clock.POSIX
s1 = "Wed, 07 Dec 2011 10:09:21 +0000"
s2 = "Wed, 07 Dec 2011 10:11:00 +0000"
t1 = fromJust $ tryParseTime s1
t2 = fromJust $ tryParseTime s2
pt1 = utcTimeToPOSIXSeconds t1 -- :: UTCTime -> POSIXTime
pt2 = utcTimeToPOSIXSeconds t2
pt3 = pt1 + (pt2 - pt1) / 2
t3 = posixSecondsToUTCTime pt3
t = compare t1 t2
tryParseTime :: String -> Maybe UTCTime
tryParseTime timeStr = tryFormat (parseTime defaultTimeLocale timeFormat1
timeStr :: Maybe UTCTime)
where
tryFormat time
| time == Nothing = parseTime defaultTimeLocale timeFormat2 timeStr
:: Maybe UTCTime
| otherwise = time
timeFormat1 = "%a, %d %b %Y %T %z"
timeFormat2 = "%m/%e/%Y %l:%M:%S %p"
-- timeFormat1 = "%m/%d/%Y %l:%M:%S %p"
On Thu, Dec 8, 2011 at 6:30 PM, dokondr
I need to parse time strings like "Wed, 07 Dec 2011 10:09:21 +0000" to a type that: 1) implements Eq, Ord 2) is numerical, so I could subtract one value from another to find the difference or interval length
To answer 1) requirement I wrote the following snippet. Yet I could not subtract UTCTime values. How can I convert them to milliseconds?
import Data.Time.Format import Data.Time.Clock import Locale import Data.Maybe
s1 = "Wed, 07 Dec 2011 10:09:21 +0000" s2 = "Wed, 07 Dec 2011 10:11:00 +0000" t1 = fromJust $ tryParseTime s1 t2 = fromJust $ tryParseTime s2
t = compare t1 t2
tryParseTime :: String -> Maybe UTCTime tryParseTime timeStr = tryFormat (parseTime defaultTimeLocale timeFormat1 timeStr :: Maybe UTCTime) where tryFormat time | time == Nothing = parseTime defaultTimeLocale timeFormat2 timeStr :: Maybe UTCTime | otherwise = time
timeFormat1 = "%a, %d %b %Y %T %z" timeFormat2 = "%m/%e/%Y %l:%M:%S %p"
On Thu, Dec 8, 2011 at 6:12 PM, Erik Hesselink
wrote: I'm not sure if you really need ClockTime (from old-time), but if you don't, the types from the 'time' package are all parseable with `parseTime` [1].
Erik
[1]
http://hackage.haskell.org/packages/archive/time/latest/doc/html/Data-Time-F...
On Thu, Dec 8, 2011 at 14:16, dokondr
wrote: Hi, What would be the simplest way to convert strings like "Wed, 07 Dec 2011 10:09:21 +0000" to System.Time.ClockTime ?
Thanks!
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