Copyright	(c) Dong Han 2020 (c) Kazu Yamamoto 2019
License	BSD
Maintainer	winterland1989@gmail.com
Stability	experimental
Portability	non-portable
Safe Haskell	None
Language	Haskell2010

Z.IO.Time

Contents

SystemTime
Parsing
Formatting
Format

Description

This module provides functions directly work on SystemTime type, a compact time type from time library. For advanced time editing, use time library.

Synopsis

data SystemTime = MkSystemTime {
- systemSeconds :: !Int64
- systemNanoseconds :: !Word32
}
getSystemTime :: IO SystemTime
parseSystemTime :: TimeFormat -> CBytes -> IO SystemTime
parseSystemTimeGMT :: TimeFormat -> CBytes -> SystemTime
formatSystemTime :: TimeFormat -> SystemTime -> IO CBytes
formatSystemTimeGMT :: TimeFormat -> SystemTime -> CBytes
type TimeFormat = CBytes
simpleDateFormat :: TimeFormat
iso8061DateFormat :: TimeFormat
webDateFormat :: TimeFormat
mailDateFormat :: TimeFormat

SystemTime

data SystemTime #

SystemTime is time returned by system clock functions. Its semantics depends on the clock function, but the epoch is typically the beginning of 1970. Note that systemNanoseconds of 1E9 to 2E9-1 can be used to represent leap seconds.

Constructors

MkSystemTime
Fields systemSeconds :: !Int64 systemNanoseconds :: !Word32

Instances

Instances details

Eq SystemTime
Instance details Defined in Data.Time.Clock.Internal.SystemTime Methods (==) :: SystemTime -> SystemTime -> Bool # (/=) :: SystemTime -> SystemTime -> Bool #
Ord SystemTime
Instance details Defined in Data.Time.Clock.Internal.SystemTime Methods compare :: SystemTime -> SystemTime -> Ordering # (<) :: SystemTime -> SystemTime -> Bool # (<=) :: SystemTime -> SystemTime -> Bool # (>) :: SystemTime -> SystemTime -> Bool # (>=) :: SystemTime -> SystemTime -> Bool # max :: SystemTime -> SystemTime -> SystemTime # min :: SystemTime -> SystemTime -> SystemTime #
Show SystemTime
Instance details Defined in Data.Time.Clock.Internal.SystemTime Methods showsPrec :: Int -> SystemTime -> ShowS # show :: SystemTime -> String # showList :: [SystemTime] -> ShowS #
NFData SystemTime
Instance details Defined in Data.Time.Clock.Internal.SystemTime Methods rnf :: SystemTime -> () #

getSystemTime :: IO SystemTime #

Get the system time, epoch start of 1970 UTC, leap-seconds ignored. getSystemTime is typically much faster than getCurrentTime.

Parsing

parseSystemTime :: TimeFormat -> CBytes -> IO SystemTime Source #

Parsing CBytes to SystemTime interpreting as localtime.

This is a wrapper for strptime_l(). Many implementations of strptime_l() do not support %Z and some implementations of strptime_l() do not support %z, either. systemNanoSeconds is always set to 0.

The result depends on the TZ environment variable.

> setEnv TZ "Africa/Algiers"
parseSystemTime simpleDateFormat "1970-01-01 00:00:00"
MkSystemTime {systemSeconds = 0, systemNanoseconds = 0}
> setEnv TZ "Asia/Shanghai"
parseSystemTime simpleDateFormat "1970-01-01 00:00:00"
MkSystemTime {systemSeconds = -28800, systemNanoseconds = 0}

parseSystemTimeGMT :: TimeFormat -> CBytes -> SystemTime Source #

Parsing CBytes to SystemTime interpreting as GMT. This is a wrapper for strptime_l(). systemNanoSeconds is always set to 0.

>>> parseSystemTimeGMT webDateFormat "Thu, 01 Jan 1970 00:00:00 GMT"
MkSystemTime {systemSeconds = 0, systemNanoseconds = 0}

Formatting

formatSystemTime :: TimeFormat -> SystemTime -> IO CBytes Source #

Formatting SystemTime to CBytes in local time.

This is a wrapper for strftime_l(), systemNanoseconds is ignored. The result depends on the TZ environment variable.

formatSystemTimeGMT :: TimeFormat -> SystemTime -> CBytes Source #

Formatting SystemTime to CBytes in GMT.

This is a wrapper for strftime_l(), systemNanoseconds is ignored.

>>> formatSystemTimeGMT webDateFormat $ MkSystemTime 0 0
"Thu, 01 Jan 1970 00:00:00 GMT"
>>> let ut = MkSystemTime 100 200
>>> let str = formatSystemTimeGMT "%s" ut
>>> let ut' = parseSystemTimeGMT "%s" str
>>> ((==) `on` systemSeconds) ut ut'
True
>>> ((==) `on` systemNanoseconds) ut ut'
False

Format

type TimeFormat = CBytes Source #

strftime time format.

simpleDateFormat :: TimeFormat Source #

Simple format 2020-10-16 03:15:29.

The value is "%Y-%m-%d %H:%M:%S". This should be used with formatSystemTime and parseSystemTime.

iso8061DateFormat :: TimeFormat Source #

Simple format 2020-10-16T03:15:29.

The value is "%Y-%m-%dT%H:%M:%S%z". This should be used with formatSystemTime and parseSystemTime.

webDateFormat :: TimeFormat Source #

Format for web (RFC 2616).

The value is "%a, %d %b %Y %H:%M:%S GMT". This should be used with formatSystemTimeGMT and parseSystemTimeGMT.

mailDateFormat :: TimeFormat Source #

Format for e-mail (RFC 5322).

The value is "%a, %d %b %Y %H:%M:%S %z". This should be used with formatSystemTime and parseSystemTime.