Convert to throwing functions

Sources/JulianDayNumber/ArmenianCalendar.swift

@@ -37,12 +37,12 @@ public struct ArmenianCalendar: Calendar {
 	/// The converter for the Armenian calendar.
 	static let converter = JDNConverter(y: 5268, j: 317, m: 0, n: 13, r: 1, p: 365, q: 0, v: 0, u: 1, s: 30, t: 0, w: 0)
 
-	public static func julianDayNumberFromDate(_ date: DateType) -> JulianDayNumber {
-		converter.julianDayNumberFromDate(date)
+	public static func julianDayNumberFromDate(_ date: DateType) throws -> JulianDayNumber {
+		try converter.julianDayNumberFromDate(date)
 	}
 
-	public static func dateFromJulianDayNumber(_ J: JulianDayNumber) -> DateType {
-		converter.dateFromJulianDayNumber(J)
+	public static func dateFromJulianDayNumber(_ J: JulianDayNumber) throws -> DateType {
+		try converter.dateFromJulianDayNumber(J)
 	}
 
 	/// The number of months in one year.

Sources/JulianDayNumber/AstronomicalCalendar.swift

@@ -27,8 +27,10 @@ public struct AstronomicalCalendar: Calendar {
 	/// - parameter date: A date to convert.
 	///
 	/// - returns: The Julian day number corresponding to the specified date.
-	public static func julianDayNumberFromDate(_ date: DateType) -> JulianDayNumber {
-		date < firstGregorianCalendarDate ? JulianCalendar.julianDayNumberFromDate(date) : GregorianCalendar.julianDayNumberFromDate(date)
+	///
+	/// - throws: An error if the date could not be converted to a Julian Day Number.
+	public static func julianDayNumberFromDate(_ date: DateType) throws -> JulianDayNumber {
+		date < firstGregorianCalendarDate ? try JulianCalendar.julianDayNumberFromDate(date) : try GregorianCalendar.julianDayNumberFromDate(date)
 	}
 
 	/// Converts a Julian day number to a date in the astronomical calendar.
@@ -38,8 +40,10 @@ public struct AstronomicalCalendar: Calendar {
 	/// - parameter J: A Julian day number.
 	///
 	/// - returns: The date corresponding to the specified Julian day number.
-	public static func dateFromJulianDayNumber(_ J: JulianDayNumber) -> DateType {
-		J < GregorianCalendar.effectiveJulianDayNumber ? JulianCalendar.dateFromJulianDayNumber(J): GregorianCalendar.dateFromJulianDayNumber(J)
+	///
+	/// - throws: An error if the Julian Day Number could not be converted to a date.
+	public static func dateFromJulianDayNumber(_ J: JulianDayNumber) throws -> DateType {
+		J < GregorianCalendar.effectiveJulianDayNumber ? try JulianCalendar.dateFromJulianDayNumber(J): try GregorianCalendar.dateFromJulianDayNumber(J)
 	}
 
 	/// The number of months in one year.

Sources/JulianDayNumber/BahaiCalendar.swift

@@ -44,12 +44,12 @@ public struct BahaiCalendar: Calendar {
 	/// The converter for the Baháʼí calendar.
 	static let converter = JDNGregorianConverter(y: 6560, j: 1412, m: 19, n: 20, r: 4, p: 1461, q: 0, v: 3, u: 1, s: 19, t: 0, w: 0, A: 184, B: 274273, C: -50)
 
-	public static func julianDayNumberFromDate(_ date: DateType) -> JulianDayNumber {
-		converter.julianDayNumberFromDate(date)
+	public static func julianDayNumberFromDate(_ date: DateType) throws -> JulianDayNumber {
+		try converter.julianDayNumberFromDate(date)
 	}
 
-	public static func dateFromJulianDayNumber(_ J: JulianDayNumber) -> DateType {
-		converter.dateFromJulianDayNumber(J)
+	public static func dateFromJulianDayNumber(_ J: JulianDayNumber) throws -> DateType {
+		try converter.dateFromJulianDayNumber(J)
 	}
 
 	/// The number of months in one year.

Sources/JulianDayNumber/Calendar+JulianDate.swift

@@ -40,8 +40,10 @@ extension Calendar {
 	/// - parameter s: A second number on the half-open interval `[0, 60)`.
 	///
 	/// - returns: The Julian date corresponding to the specified year, month, day, hour, minute, and second.
-	public static func julianDateFrom(year Y: Year, month M: Month, day D: Day, hour h: Hour = 0, minute m: Minute = 0, second s: Second = 0) -> JulianDate {
-		julianDateFrom(year: Y, month: M, day: Double(D) + fractionalDayFrom(hour: h, minute: m, second: s))
+	///
+	/// - throws: An error if the year, month, day, hour, minute, and second could not be converted to a Julian date.
+	public static func julianDateFrom(year Y: Year, month M: Month, day D: Day, hour h: Hour = 0, minute m: Minute = 0, second s: Second = 0) throws -> JulianDate {
+		try julianDateFrom(year: Y, month: M, day: Double(D) + fractionalDayFrom(hour: h, minute: m, second: s))
 	}
 
 	/// Converts the specified year, month, and decimal fractional day to a Julian date and returns the result.
@@ -53,20 +55,24 @@ extension Calendar {
 	/// - parameter D: A decimal fractional day number.
 	///
 	/// - returns: The Julian date corresponding to the specified year, month, and decimal day.
-	public static func julianDateFrom(year Y: Year, month M: Month, day D: FractionalDay) -> JulianDate {
+	///
+	/// - throws: An error if the year, month, and decimal fractional day could not be converted to a Julian date.
+	public static func julianDateFrom(year Y: Year, month M: Month, day D: FractionalDay) throws -> JulianDate {
 		let (day, dayFraction) = modf(D)
-		return Double(julianDayNumberFrom(year: Y, month: M, day: Int(day))) - 0.5 + dayFraction
+		return Double(try julianDayNumberFrom(year: Y, month: M, day: Int(day))) - 0.5 + dayFraction
 	}
 
 	/// Converts the specified Julian date to a year, month, day, hour, minute, and second and returns the result.
 	///
 	/// - parameter julianDate: A Julian date.
 	///
 	/// - returns: The year, month, day, hour, minute, and second corresponding to the specified Julian date.
-	public static func dateAndTimeFromJulianDate(_ julianDate: JulianDate) -> (year: Year, month: Month, day: Day, hour: Hour, minute: Minute, second: Second) {
+	///
+	/// - throws: An error if the Julian date could not be converted to a year, month, and decimal fractional day.
+	public static func dateAndTimeFromJulianDate(_ julianDate: JulianDate) throws -> (year: Year, month: Month, day: Day, hour: Hour, minute: Minute, second: Second) {
 		let julianDatePlus12Hours = julianDate + 0.5
 		let J = JulianDayNumber(julianDatePlus12Hours.rounded(.down))
-		let (Y, M, D) = dateFromJulianDayNumber(J)
+		let (Y, M, D) = try dateFromJulianDayNumber(J)
 		var (_, dayFraction) = modf(julianDatePlus12Hours)
 		if dayFraction < 0 {
 			dayFraction += 1

Sources/JulianDayNumber/Calendar.swift

@@ -76,8 +76,10 @@ extension Calendar {
 	/// - parameter D: A day number.
 	///
 	/// - returns: The Julian day number corresponding to the specified year, month, and day.
-	public static func julianDayNumberFrom(year Y: Year, month M: Month, day D: Day) -> JulianDayNumber {
-		julianDayNumberFromDate((Y, M, D))
+	///
+	/// - throws: An error if the year, month, and day could not be converted to a Julian Day Number.
+	public static func julianDayNumberFrom(year Y: Year, month M: Month, day D: Day) throws -> JulianDayNumber {
+		try julianDayNumberFromDate((Y, M, D))
 	}
 
 	/// An ordinal day.
@@ -90,8 +92,10 @@ extension Calendar {
 	/// - parameter D: A day number.
 	///
 	/// - returns: The ordinal day corresponding to the specified year, month, and day.
-	public static func ordinalDayFrom(year Y: Year, month M: Month, day D: Day) -> OrdinalDay {
-		OrdinalDay(julianDayNumberFrom(year: Y, month: M, day: D) - julianDayNumberFrom(year: Y, month: 1, day: 1) + 1)
+	///
+	/// - throws: An error if the year, month, and day could not be converted to an ordinal day.
+	public static func ordinalDayFrom(year Y: Year, month M: Month, day D: Day) throws -> OrdinalDay {
+		try OrdinalDay(julianDayNumberFrom(year: Y, month: M, day: D) - julianDayNumberFrom(year: Y, month: 1, day: 1) + 1)
 	}
 
 	/// Converts a year and ordinal day to a year, month, and day and returns the result.
@@ -100,8 +104,10 @@ extension Calendar {
 	/// - parameter N: An ordinal day number.
 	///
 	/// - returns: The year, month, and day corresponding to the specified year and ordinal day.
-	public static func dateFrom(year Y: Year, ordinalDay N: OrdinalDay) -> DateType {
-		dateFromJulianDayNumber(julianDayNumberFrom(year: Y, month: 1, day: 1) + JulianDayNumber(N) - 1)
+	///
+	/// - throws: An error if the year and ordinal day could not be converted to a date.
+	public static func dateFrom(year Y: Year, ordinalDay N: OrdinalDay) throws -> DateType {
+		try dateFromJulianDayNumber(julianDayNumberFrom(year: Y, month: 1, day: 1) + JulianDayNumber(N) - 1)
 	}
 }
 
@@ -114,7 +120,9 @@ extension Calendar {
 	/// - parameter calendar: The calendar to use for conversion.
 	///
 	/// - returns: The specified date converted to a date in the specified calendar.
-	public static func convert<C>(year Y: Year, month M: Month, day D: Day, to calendar: C.Type) -> C.DateType where C: CalendarProtocol {
-		convertDate((Y, M, D), using: calendar)
+	///
+	/// - throws: An error if the year, month, and day could not be converted to a date in the specified calendar.
+	public static func convert<C>(year Y: Year, month M: Month, day D: Day, to calendar: C.Type) throws -> C.DateType where C: CalendarProtocol {
+		try convertDate((Y, M, D), using: calendar)
 	}
 }

Sources/JulianDayNumber/CopticCalendar.swift

@@ -37,12 +37,12 @@ public struct CopticCalendar: Calendar {
 	/// The converter for the Coptic calendar.
 	static let converter = JDNConverter(y: 4996, j: 124, m: 0, n: 13, r: 4, p: 1461, q: 0, v: 3, u: 1, s: 30, t: 0, w: 0)
 
-	public static func julianDayNumberFromDate(_ date: DateType) -> JulianDayNumber {
-		converter.julianDayNumberFromDate(date)
+	public static func julianDayNumberFromDate(_ date: DateType) throws -> JulianDayNumber {
+		try converter.julianDayNumberFromDate(date)
 	}
 
-	public static func dateFromJulianDayNumber(_ J: JulianDayNumber) -> DateType {
-		converter.dateFromJulianDayNumber(J)
+	public static func dateFromJulianDayNumber(_ J: JulianDayNumber) throws -> DateType {
+		try converter.dateFromJulianDayNumber(J)
 	}
 
 	/// The number of months in one year.

Sources/JulianDayNumber/EgyptianCalendar.swift

@@ -37,12 +37,12 @@ public struct EgyptianCalendar: Calendar {
 	/// The converter for the Egyptian calendar.
 	static let converter = JDNConverter(y: 3968, j: 47, m: 0, n: 13, r: 1, p: 365, q: 0, v: 0, u: 1, s: 30, t: 0, w: 0)
 
-	public static func julianDayNumberFromDate(_ date: DateType) -> JulianDayNumber {
-		converter.julianDayNumberFromDate(date)
+	public static func julianDayNumberFromDate(_ date: DateType) throws -> JulianDayNumber {
+		try converter.julianDayNumberFromDate(date)
 	}
 
-	public static func dateFromJulianDayNumber(_ J: JulianDayNumber) -> DateType {
-		converter.dateFromJulianDayNumber(J)
+	public static func dateFromJulianDayNumber(_ J: JulianDayNumber) throws -> DateType {
+		try converter.dateFromJulianDayNumber(J)
 	}
 
 	/// The number of months in one year.

Sources/JulianDayNumber/EthiopianCalendar.swift

@@ -37,12 +37,12 @@ public struct EthiopianCalendar: Calendar {
 	/// The converter for the Ethiopian calendar.
 	static let converter = JDNConverter(y: 4720, j: 124, m: 0, n: 13, r: 4, p: 1461, q: 0, v: 3, u: 1, s: 30, t: 0, w: 0)
 
-	public static func julianDayNumberFromDate(_ date: DateType) -> JulianDayNumber {
-		converter.julianDayNumberFromDate(date)
+	public static func julianDayNumberFromDate(_ date: DateType) throws -> JulianDayNumber {
+		try converter.julianDayNumberFromDate(date)
 	}
 
-	public static func dateFromJulianDayNumber(_ J: JulianDayNumber) -> DateType {
-		converter.dateFromJulianDayNumber(J)
+	public static func dateFromJulianDayNumber(_ J: JulianDayNumber) throws -> DateType {
+		try converter.dateFromJulianDayNumber(J)
 	}
 
 	/// The number of months in one year.

Sources/JulianDayNumber/FrenchRepublicanCalendar.swift

@@ -42,12 +42,12 @@ public struct FrenchRepublicanCalendar: Calendar {
 	/// The converter for the French Republican calendar.
 	static let converter = JDNGregorianConverter(y: 6504, j: 111, m: 0, n: 13, r: 4, p: 1461, q: 0, v: 3, u: 1, s: 30, t: 0, w: 0, A: 396, B: 578797, C: -51)
 
-	public static func julianDayNumberFromDate(_ date: DateType) -> JulianDayNumber {
-		converter.julianDayNumberFromDate(date)
+	public static func julianDayNumberFromDate(_ date: DateType) throws -> JulianDayNumber {
+		try converter.julianDayNumberFromDate(date)
 	}
 
-	public static func dateFromJulianDayNumber(_ J: JulianDayNumber) -> DateType {
-		converter.dateFromJulianDayNumber(J)
+	public static func dateFromJulianDayNumber(_ J: JulianDayNumber) throws -> DateType {
+		try converter.dateFromJulianDayNumber(J)
 	}
 
 	/// The number of months in one year.

Sources/JulianDayNumber/GregorianCalendar.swift

@@ -53,7 +53,7 @@ public struct GregorianCalendar: Calendar {
 	//   Fliegel, H.F. & van Flandern, T.C. 1968, Communications of the ACM, 11, 657.
 	//   https://doi.org/10.1145/364096.364097
 
-	public static func julianDayNumberFromDate(_ date: DateType) -> JulianDayNumber {
+	public static func julianDayNumberFromDate(_ date: DateType) throws -> JulianDayNumber {
 		// Years greater than maxY cause arithmetic overflow
 		// when computing J even when the final result is ≤ .max
 		// N.B. this is an estimated upper bound
@@ -93,7 +93,7 @@ public struct GregorianCalendar: Calendar {
 		return J
 	}
 
-	public static func dateFromJulianDayNumber(_ JD: JulianDayNumber) -> DateType {
+	public static func dateFromJulianDayNumber(_ JD: JulianDayNumber) throws -> DateType {
 		// JDN values greater than maxJD cause arithmetic overflow
 		// when computing L
 		let maxJD = .max - 68569

Sources/JulianDayNumber/HebrewCalendar.swift

@@ -64,7 +64,7 @@ public struct HebrewCalendar: Calendar {
 	/// The recurrence cycle of the Hebrew calendar is 689,472 years, 8,527,680 months, 35,975,351 weeks, or 251,827,457 days.
 	static let recurrenceCycle = (years: 689472, days: 251827457)
 
-	public static func julianDayNumberFromDate(_ date: DateType) -> JulianDayNumber {
+	public static func julianDayNumberFromDate(_ date: DateType) throws -> JulianDayNumber {
 		var Y = date.year
 		var cycles = 0
 
@@ -85,7 +85,7 @@ public struct HebrewCalendar: Calendar {
 		return J
 	}
 
-	public static func dateFromJulianDayNumber(_ J: JulianDayNumber) -> DateType {
+	public static func dateFromJulianDayNumber(_ J: JulianDayNumber) throws -> DateType {
 		var J = J
 		var cycles = 0
 

Sources/JulianDayNumber/ISOCalendar.swift

@@ -26,13 +26,13 @@ public struct ISOCalendar: CalendarProtocol {
 	/// This JDN corresponds to January 3, 1 CE in the Julian calendar.
 	public static let epoch = GregorianCalendar.epoch
 
-	public static func julianDayNumberFromDate(_ date: DateType) -> JulianDayNumber {
-		GregorianCalendar.julianDayNumberFromDate(dateFromISO(year: date.year, week: date.week, weekday: date.weekday))
+	public static func julianDayNumberFromDate(_ date: DateType) throws -> JulianDayNumber {
+		try GregorianCalendar.julianDayNumberFromDate(dateFromISO(year: date.year, week: date.week, weekday: date.weekday))
 	}
 
-	public static func dateFromJulianDayNumber(_ J: JulianDayNumber) -> DateType {
-		let (Y, M, D) = GregorianCalendar.dateFromJulianDayNumber(J)
-		return isoDateFrom(year: Y, month: M, day: D)
+	public static func dateFromJulianDayNumber(_ J: JulianDayNumber) throws -> DateType {
+		let (Y, M, D) = try GregorianCalendar.dateFromJulianDayNumber(J)
+		return try isoDateFrom(year: Y, month: M, day: D)
 	}
 
 	/// Returns the number of ISO full weeks in a year.
@@ -56,13 +56,13 @@ public struct ISOCalendar: CalendarProtocol {
 		return 52
 	}
 
-	/// Returns the ISO weekday for the specified year, month, and day.
+	/// Returns the ISO weekday for the specified Gregorian year, month, and day.
 	///
 	/// - parameter Y: A Gregorian year number.
 	/// - parameter M: A month number.
 	/// - parameter D: A day number.
 	///
-	/// - returns: The ISO weekday from `1` (Monday) to `7` (Sunday) corresponding to the specified year, month, and day.
+	/// - returns: The ISO weekday from `1` (Monday) to `7` (Sunday) corresponding to the specified Gregorian year, month, and day.
 	static func isoWeekdayFrom(year Y: Int, month M: Int, day D: Int) -> WeekdayNumber {
 		let weekday = GregorianCalendar.dayOfWeekFrom(year: Y, month: M, day: D) - 1
 		return weekday < 1 ? weekday + 7 : weekday
@@ -73,15 +73,17 @@ public struct ISOCalendar: CalendarProtocol {
 		date.weekday > 0 && date.weekday <= 7 && date.week > 0 && date.week <= isoWeeksInYear(date.year)
 	}
 
-	/// Returns the ISO week date for the specified year, month, and day.
+	/// Returns the ISO week date for the specified Gregorian year, month, and day.
 	///
 	/// - parameter Y: A Gregorian year number.
 	/// - parameter M: A month number.
 	/// - parameter D: A day number.
 	///
-	/// - returns: The ISO week date corresponding to the specified year, month, and day.
-	public static func isoDateFrom(year Y: Int, month M: Int, day D: Int) -> (year: Year, week: WeekNumber, weekday: WeekdayNumber) {
-		let N = GregorianCalendar.ordinalDayFrom(year: Y, month: M, day: D)
+	/// - returns: The ISO week date corresponding to the specified Gregorian year, month, and day.
+	///
+	/// - throws: An error if the year, month, and day could not be converted to an ISO week date.
+	public static func isoDateFrom(year Y: Int, month M: Int, day D: Int) throws -> (year: Year, week: WeekNumber, weekday: WeekdayNumber) {
+		let N = try GregorianCalendar.ordinalDayFrom(year: Y, month: M, day: D)
 		let weekday = isoWeekdayFrom(year: Y, month: M, day: D)
 		let w = (10 + N - weekday) / 7
 		if w == 0 {
@@ -92,15 +94,17 @@ public struct ISOCalendar: CalendarProtocol {
 		return (Y, w, weekday)
 	}
 
-	/// Returns the date for the specified year, ISO week number, and ISO weekday number.
+	/// Returns the Gregorian date for the specified year, ISO week number, and ISO weekday number.
 	///
 	/// - parameter Y: A Gregorian year number.
 	/// - parameter week: An ISO week number.
 	/// - parameter weekday: An ISO weekday number.
 	///
-	/// - returns: The date corresponding to the specified Gregorian year, ISO week number, and ISO weekday number.
-	public static func dateFromISO(year Y: Year, week: WeekNumber, weekday: WeekdayNumber) -> (year: Int, month: Int, day: Int) {
+	/// - returns: The Gregorian date corresponding to the specified Gregorian year, ISO week number, and ISO weekday number.
+	///
+	/// - throws: An error if the year, ISO week number, and ISO weekday number could not be converted to a date.
+	public static func dateFromISO(year Y: Year, week: WeekNumber, weekday: WeekdayNumber) throws -> GregorianCalendar.DateType {
 		let N = week * 7 + weekday - isoWeekdayFrom(year: Y, month: 1, day: 4) - 3
-		return GregorianCalendar.dateFrom(year: Y, ordinalDay: N)
+		return try GregorianCalendar.dateFrom(year: Y, ordinalDay: N)
 	}
 }

Sources/JulianDayNumber/IslamicCalendar.swift

@@ -39,12 +39,12 @@ public struct IslamicCalendar: Calendar {
 	/// The converter for the Islamic calendar.
 	static let converter = JDNConverter(y: 5519, j: 7664, m: 0, n: 12, r: 30, p: 10631, q: 14, v: 15, u: 100, s: 2951, t: 51, w: 10)
 
-	public static func julianDayNumberFromDate(_ date: DateType) -> JulianDayNumber {
-		converter.julianDayNumberFromDate(date)
+	public static func julianDayNumberFromDate(_ date: DateType) throws -> JulianDayNumber {
+		try converter.julianDayNumberFromDate(date)
 	}
 
-	public static func dateFromJulianDayNumber(_ J: JulianDayNumber) -> DateType {
-		converter.dateFromJulianDayNumber(J)
+	public static func dateFromJulianDayNumber(_ J: JulianDayNumber) throws -> DateType {
+		try converter.dateFromJulianDayNumber(J)
 	}
 
 	/// The number of months in one year.

Sources/JulianDayNumber/JDNConverter.swift

@@ -47,7 +47,9 @@ struct JDNConverter {
 	/// - parameter date: A date to convert.
 	///
 	/// - returns: The Julian day number corresponding to the specified date.
-	func julianDayNumberFromDate(_ date: Calendar.YearMonthDay) -> JulianDayNumber {
+	///
+	/// - throws: An error if the date could not be converted to a Julian Day Number.
+	func julianDayNumberFromDate(_ date: Calendar.YearMonthDay) throws -> JulianDayNumber {
 		// Arithmetic upper limit
 		// `Y` values larger than this cause overflow when `e` is computed
 		let maxY = (.max / p) - y + (n - (date.month - m)) / n
@@ -93,7 +95,9 @@ struct JDNConverter {
 	/// - parameter J: A Julian day number.
 	///
 	/// - returns: The date corresponding to the specified Julian day number.
-	func dateFromJulianDayNumber(_ J: JulianDayNumber) -> Calendar.YearMonthDay {
+	///
+	/// - throws: An error if the Julian Day Number could not be converted to a date.
+	func dateFromJulianDayNumber(_ J: JulianDayNumber) throws -> Calendar.YearMonthDay {
 		// Arithmetic upper limit
 		// `J` values larger than this cause overflow when `e` is computed
 		let maxJ = (.max - v) / r - j