diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/pure/times.nim | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/lib/pure/times.nim b/lib/pure/times.nim index 113f73d2a..7851bf158 100644 --- a/lib/pure/times.nim +++ b/lib/pure/times.nim @@ -288,6 +288,13 @@ type YeardayRange* = range[0..365] NanosecondRange* = range[0..999_999_999] + IsoWeekRange* = range[1 .. 53] + ## An ISO 8601 calendar week number. + IsoYear* = distinct int + ## An ISO 8601 calendar year number. + ## + ## .. warning:: The ISO week-based year can correspond to the following or previous year from 29 December to January 3. + Time* = object ## Represents a point in time. seconds: int64 nanosecond: NanosecondRange @@ -529,6 +536,54 @@ proc getDaysInYear*(year: int): int = doAssert getDaysInYear(2001) == 365 result = 365 + (if isLeapYear(year): 1 else: 0) +proc `==`*(a, b: IsoYear): bool {.borrow.} +proc `$`*(p: IsoYear): string {.borrow.} + +proc getWeeksInIsoYear*(y: IsoYear): IsoWeekRange {.since: (1, 5).} = + ## Returns the number of weeks in the specified ISO 8601 week-based year, which can be + ## either 53 or 52. + runnableExamples: + assert getWeeksInIsoYear(IsoYear(2000)) == 52 + assert getWeeksInIsoYear(IsoYear(2001)) == 53 + + var y = int(y) + + # support negative years + y = if y < 0: 400 + y mod 400 else: y + + # source: https://webspace.science.uu.nl/~gent0113/calendar/isocalendar.htm + let p = (y + (y div 4) - (y div 100) + (y div 400)) mod 7 + let y1 = y - 1 + let p1 = (y1 + (y1 div 4) - (y1 div 100) + (y1 div 400)) mod 7 + if p == 4 or p1 == 3: 53 else: 52 + +proc getIsoWeekAndYear*(dt: DateTime): + tuple[isoweek: IsoWeekRange, isoyear: IsoYear] {.since: (1, 5).} = + ## Returns the ISO 8601 week and year. + ## + ## .. warning:: The ISO week-based year can correspond to the following or previous year from 29 December to January 3. + runnableExamples: + assert getIsoWeekAndYear(initDateTime(21, mApr, 2018, 00, 00, 00)) == (isoweek: 16.IsoWeekRange, isoyear: 2018.IsoYear) + block: + let (w, y) = getIsoWeekAndYear(initDateTime(30, mDec, 2019, 00, 00, 00)) + assert w == 01.IsoWeekRange + assert y == 2020.IsoYear + assert getIsoWeekAndYear(initDateTime(13, mSep, 2020, 00, 00, 00)) == (isoweek: 37.IsoWeekRange, isoyear: 2020.IsoYear) + block: + let (w, y) = getIsoWeekAndYear(initDateTime(2, mJan, 2021, 00, 00, 00)) + assert w.int > 52 + assert w.int < 54 + assert y.int mod 100 == 20 + + # source: https://webspace.science.uu.nl/~gent0113/calendar/isocalendar.htm + var w = (dt.yearday.int - dt.weekday.int + 10) div 7 + if w < 1: + (isoweek: getWeeksInIsoYear(IsoYear(dt.year - 1)), isoyear: IsoYear(dt.year - 1)) + elif (w > getWeeksInIsoYear(IsoYear(dt.year))): + (isoweek: IsoWeekRange(1), isoyear: IsoYear(dt.year + 1)) + else: + (isoweek: IsoWeekRange(w), isoyear: IsoYear(dt.year)) + proc stringifyUnit(value: int | int64, unit: TimeUnit): string = ## Stringify time unit with it's name, lowercased let strUnit = $unit @@ -2579,6 +2634,33 @@ proc `-=`*(t: var Time, b: TimeInterval) = t = t - b # +# Day of year +# + +proc initDateTime*(weekday: WeekDay, isoweek: IsoWeekRange, isoyear: IsoYear, + hour: HourRange, minute: MinuteRange, second: SecondRange, + nanosecond: NanosecondRange, + zone: Timezone = local()): DateTime {.since: (1, 5).} = + ## Create a new `DateTime <#DateTime>`_ from a weekday and an ISO 8601 week number and year + ## in the specified timezone. + ## + ## .. warning:: The ISO week-based year can correspond to the following or previous year from 29 December to January 3. + runnableExamples: + assert initDateTime(21, mApr, 2018, 00, 00, 00) == initDateTime(dSat, 16, 2018.IsoYear, 00, 00, 00) + assert initDateTime(30, mDec, 2019, 00, 00, 00) == initDateTime(dMon, 01, 2020.IsoYear, 00, 00, 00) + assert initDateTime(13, mSep, 2020, 00, 00, 00) == initDateTime(dSun, 37, 2020.IsoYear, 00, 00, 00) + assert initDateTime(2, mJan, 2021, 00, 00, 00) == initDateTime(dSat, 53, 2020.IsoYear, 00, 00, 00) + + # source https://webspace.science.uu.nl/~gent0113/calendar/isocalendar.htm + let d = isoweek * 7 + weekday.int - initDateTime(4, mJan, isoyear.int, 00, 00, 00).weekday.int - 4 + initDateTime(1, mJan, isoyear.int, hour, minute, second, nanosecond, zone) + initTimeInterval(days=d) + +proc initDateTime*(weekday: WeekDay, isoweek: IsoWeekRange, isoyear: IsoYear, + hour: HourRange, minute: MinuteRange, second: SecondRange, + zone: Timezone = local()): DateTime {.since: (1, 5).} = + initDateTime(weekday, isoweek, isoyear, hour, minute, second, 0, zone) + +# # Other # |