Safe Haskell	None
Language	Haskell2010

Haspara.Date

Contents

Date

Description

This module provides definitions and functions to encode and work on date values.

Synopsis

data Date
fromDay :: Day -> Date
fromYMD :: Integer -> Int -> Int -> Date
fromString :: MonadFail m => String -> m Date
fromFormattedString :: MonadFail m => String -> String -> m Date
fromText :: MonadFail m => Text -> m Date
fromFormattedText :: MonadFail m => String -> Text -> m Date
toDay :: Date -> Day
toYMD :: Date -> (Integer, Int, Int)
toString :: Date -> String
toFormattedString :: String -> Date -> String
toText :: Date -> Text
toFormattedText :: String -> Date -> Text
addDays :: Integer -> Date -> Date

Date

Definition

data Date Source #

Type encoding for date values.

This is a convenience wrapper around Day type. It helps us to avoid defining orphan instances.

Instances

Instances details

Enum Date Source #
Instance details Defined in Haspara.Internal.Date Methods succ :: Date -> Date # pred :: Date -> Date # toEnum :: Int -> Date # fromEnum :: Date -> Int # enumFrom :: Date -> [Date] # enumFromThen :: Date -> Date -> [Date] # enumFromTo :: Date -> Date -> [Date] # enumFromThenTo :: Date -> Date -> Date -> [Date] #
Eq Date Source #
Instance details Defined in Haspara.Internal.Date Methods (==) :: Date -> Date -> Bool # (/=) :: Date -> Date -> Bool #
Ord Date Source #
Instance details Defined in Haspara.Internal.Date Methods compare :: Date -> Date -> Ordering # (<) :: Date -> Date -> Bool # (<=) :: Date -> Date -> Bool # (>) :: Date -> Date -> Bool # (>=) :: Date -> Date -> Bool # max :: Date -> Date -> Date # min :: Date -> Date -> Date #
Read Date Source #	`Read` instance for `Date`. `>>>` `read "2021-01-01" :: Date`2021-01-01 `>>>` `read "Just 2021-01-01" :: Maybe Date`Just 2021-01-01
Instance details Defined in Haspara.Internal.Date Methods readsPrec :: Int -> ReadS Date # readList :: ReadS [Date] # readPrec :: ReadPrec Date # readListPrec :: ReadPrec [Date] #
Show Date Source #	`Show` instance for `Date`. `>>>` `fromYMD 2020 12 31`2020-12-31
Instance details Defined in Haspara.Internal.Date Methods showsPrec :: Int -> Date -> ShowS # show :: Date -> String # showList :: [Date] -> ShowS #
Hashable Date Source #	`Hashable` instance for `Date`.
Instance details Defined in Haspara.Internal.Date Methods hashWithSalt :: Int -> Date -> Int # hash :: Date -> Int #
ToJSON Date Source #	`ToJSON` instance for `Date`. `>>>` `Aeson.encode (MkDate (read "2021-01-01"))`"\"2021-01-01\""
Instance details Defined in Haspara.Internal.Date Methods toJSON :: Date -> Value # toEncoding :: Date -> Encoding # toJSONList :: [Date] -> Value # toEncodingList :: [Date] -> Encoding #
FromJSON Date Source #	`FromJSON` instance for `Date`. `>>>` `Aeson.decode "\"2020-12-31\"" :: Maybe Date`Just 2020-12-31
Instance details Defined in Haspara.Internal.Date Methods parseJSON :: Value -> Parser Date # parseJSONList :: Value -> Parser [Date] #

Constructors

fromDay :: Day -> Date Source #

Builds a Date from a given Day.

>>> fromDay (read "2021-01-01")
2021-01-01

fromYMD :: Integer -> Int -> Int -> Date Source #

Builds a Date from a given year, month and day as in Gregorian calendar.

>>> fromYMD 2021 1 1
2021-01-01

fromString :: MonadFail m => String -> m Date Source #

Attempts to parse and return Date from a given String with ISO format.

>>> fromString "2021-01-01" :: Maybe Date
Just 2021-01-01
>>> fromString "20210101" :: Maybe Date
Nothing

fromFormattedString :: MonadFail m => String -> String -> m Date Source #

Attempts to parse and return Date from a given String with given date format.

>>> fromFormattedString "%Y-%m-%d" "2021-01-01" :: Maybe Date
Just 2021-01-01
>>> fromFormattedString "%Y%m%d" "20210101" :: Maybe Date
Just 2021-01-01
>>> fromFormattedString "%Y%m%d" "202101" :: Maybe Date
Nothing

fromText :: MonadFail m => Text -> m Date Source #

Attempts to parse and return Date from a given Text with ISO format.

>>> fromText "2021-01-01" :: Maybe Date
Just 2021-01-01
>>> fromText "20210101" :: Maybe Date
Nothing

fromFormattedText :: MonadFail m => String -> Text -> m Date Source #

Attempts to parse and return Date from a given Text with ISO format.

>>> fromFormattedText "%Y-%m-%d" "2021-01-01" :: Maybe Date
Just 2021-01-01
>>> fromFormattedText "%Y%m%d" "20210101" :: Maybe Date
Just 2021-01-01
>>> fromFormattedText "%Y%m%d" "202101" :: Maybe Date
Nothing

Conversions

toDay :: Date -> Day Source #

Converts Date value to a Day value.

>>> toDay (read "2021-01-01")
2021-01-01

toYMD :: Date -> (Integer, Int, Int) Source #

Converts Date value to a 3-tuple of year, month and day.

>>> toYMD (read "2020-12-31")
(2020,12,31)

toString :: Date -> String Source #

Converts Date value into a String value with ISO format.

>>> toString (read "2021-01-01")
"2021-01-01"

toFormattedString :: String -> Date -> String Source #

Converts Date value into a String value with the given format.

>>> toFormattedString "%Y-%m-%d" (read "2021-01-01")
"2021-01-01"
>>> toFormattedString "%d/%m/%Y" (read "2021-01-01")
"01/01/2021"

toText :: Date -> Text Source #

Converts Date value into a Text value with ISO format.

>>> toText (read "2021-01-01")
"2021-01-01"

toFormattedText :: String -> Date -> Text Source #

Converts Date value into a Text value with the given format.

>>> toFormattedText "%Y-%m-%d" (read "2021-01-01")
"2021-01-01"
>>> toFormattedText "%d/%m/%Y" (read "2021-01-01")
"01/01/2021"

Operations

addDays :: Integer -> Date -> Date Source #

Adds (or subtracts) some days.

>>> addDays (-1) $ fromYMD 2021 1 1
2020-12-31
>>> addDays 1 $ addDays (-1) $ fromYMD 2021 1 1
2021-01-01