Haskell-如何从ZonedTime提取Day和DayOfWeek时间

我正在看模块，我想要如下内容：

import Data.Time.LocalTime

timeOfDayAndDayOfWeek :: ZonedTime -> (TimeOfDay, DayOfWeek)

---

我该怎么做？

这对你有用吗

import Data.Time.LocalTime
  (ZonedTime, TimeOfDay, getZonedTime, localDay, localTimeOfDay,
   zonedTimeToLocalTime)
import Data.Time.Calendar.WeekDate (toWeekDate)

-- toWeekDate numbers the days 1 for Monday to 7 for Sunday.
data DayOfWeek = Monday|Tuesday|Wednesday|Thursday|Friday|Saturday|Sunday
  deriving (Eq, Read, Show)

instance Enum DayOfWeek where
  toEnum 0 = Sunday
  toEnum 1 = Monday
  toEnum 2 = Tuesday
  toEnum 3 = Wednesday
  toEnum 4 = Thursday
  toEnum 5 = Friday
  toEnum 6 = Saturday
  toEnum 7 = Sunday -- Yes, twice.
  toEnum n = toEnum (n `mod` 7)

  fromEnum Monday = 1
  fromEnum Tuesday = 2
  fromEnum Wednesday = 3
  fromEnum Thursday = 4
  fromEnum Friday = 5
  fromEnum Saturday = 6
  fromEnum Sunday = 7

timeOfDayAndDayOfWeek :: ZonedTime -> (TimeOfDay, DayOfWeek)
timeOfDayAndDayOfWeek zt = let
    lt = zonedTimeToLocalTime zt
    day = localDay lt
    (_, _, weekDayNumber) = toWeekDate day
    dow = toEnum weekDayNumber
    tod = localTimeOfDay lt
  in
    (tod, dow)

main :: IO ()
main = do
  zt <- getZonedTime
  let (tod, dow) = timeOfDayAndDayOfWeek zt
  print tod
  print dow

---

这对你有用吗

import Data.Time.LocalTime
  (ZonedTime, TimeOfDay, getZonedTime, localDay, localTimeOfDay,
   zonedTimeToLocalTime)
import Data.Time.Calendar.WeekDate (toWeekDate)

-- toWeekDate numbers the days 1 for Monday to 7 for Sunday.
data DayOfWeek = Monday|Tuesday|Wednesday|Thursday|Friday|Saturday|Sunday
  deriving (Eq, Read, Show)

instance Enum DayOfWeek where
  toEnum 0 = Sunday
  toEnum 1 = Monday
  toEnum 2 = Tuesday
  toEnum 3 = Wednesday
  toEnum 4 = Thursday
  toEnum 5 = Friday
  toEnum 6 = Saturday
  toEnum 7 = Sunday -- Yes, twice.
  toEnum n = toEnum (n `mod` 7)

  fromEnum Monday = 1
  fromEnum Tuesday = 2
  fromEnum Wednesday = 3
  fromEnum Thursday = 4
  fromEnum Friday = 5
  fromEnum Saturday = 6
  fromEnum Sunday = 7

timeOfDayAndDayOfWeek :: ZonedTime -> (TimeOfDay, DayOfWeek)
timeOfDayAndDayOfWeek zt = let
    lt = zonedTimeToLocalTime zt
    day = localDay lt
    (_, _, weekDayNumber) = toWeekDate day
    dow = toEnum weekDayNumber
    tod = localTimeOfDay lt
  in
    (tod, dow)

main :: IO ()
main = do
  zt <- getZonedTime
  let (tod, dow) = timeOfDayAndDayOfWeek zt
  print tod
  print dow

---

您可以从

ZonedTime

到

LocalTime

到

Day

使用

Day

可以获取

DayOfWeek

enum

---

并使用

localTimeOfDay

从

LocalTime

转到

TimeOfDay

您可以从

ZonedTime

转到

LocalTime

到

Day

使用

Day

可以获取

DayOfWeek

enum

---

并使用

localTimeOfDay

从

LocalTime

转到

TimeOfDay

希望这些信息及时到达您的手中，告诉您新年是什么时候。祝你快乐！希望你能及时收到这封信，告诉你什么时候是新年。祝你快乐！您可以使用

派生（Enum）

来避免编写样板代码。只需从

toWeekDate

的结果中减去一个即可。不幸的是，no.

toWeekDate

返回7，而不是0。您可以使用

ToekNum（weekDayNumber-1）

来避免编写自定义

Enum

实例。然后，我无法将结果传递给

ToekNum

@4castle，我添加了第二个使用包装器而不是样板的示例。您可以使用

派生（Enum）

来避免编写样板代码。只需从

toWeekDate

的结果中减去一个即可。不幸的是，no.

toWeekDate

返回7，而不是0。您可以使用

ToekNum（weekDayNumber-1）

来避免编写自定义

Enum

实例。然后，我无法将结果传递给

ToekNum

@4castle，我添加了第二个使用包装器而不是样板的示例。