Add ISO ordinal and week-date parsing

src/pkg.generated.mbti

@@ -55,6 +55,8 @@ pub fn Date::next(Self, Weekday) -> Self
 pub fn Date::next_or_same(Self, Weekday) -> Self
 pub fn Date::nth_weekday_of_month(Int, Int, Weekday, Int) -> Self raise TempoError
 pub fn Date::parse(String) -> Self raise TempoError
+pub fn Date::parse_iso_week(String) -> Self raise TempoError
+pub fn Date::parse_ordinal(String) -> Self raise TempoError
 pub fn Date::previous(Self, Weekday) -> Self
 pub fn Date::previous_or_same(Self, Weekday) -> Self
 pub fn Date::quarter(Self) -> Int

src/tempo.mbt

@@ -1263,6 +1263,47 @@ pub fn Date::parse(s : String) -> Date raise TempoError {
   Date::new(year, month, day)
 }
 
+///|
+/// Parse an ISO 8601 ordinal date in 'YYYY-DDD' format.
+///
+/// This parser is strict: it accepts only an unsigned 4-digit year, a hyphen,
+/// exactly 3 digits for the day-of-year, and end-of-input. Expanded-year output
+/// from `Date::format_ordinal` is not accepted.
+pub fn Date::parse_ordinal(s : String) -> Date raise TempoError {
+  let v = s.view()
+  let (year, v) = parse_digits(v, 4)
+  let v = consume(v, '-')
+  let (day_of_year, v) = parse_digits(v, 3)
+  match v {
+    [] => ()
+    _ => raise TempoError("unexpected trailing characters")
+  }
+  Date::from_ordinal(year, day_of_year)
+}
+
+///|
+/// Parse an ISO 8601 week date in 'YYYY-Www-D' format.
+///
+/// The leading year is the ISO week-numbering year, which can differ from the
+/// resulting calendar year near New Year. This parser is strict: it accepts
+/// only an unsigned 4-digit week-year, a literal `W`, a 2-digit week, a 1-digit
+/// weekday, and end-of-input. Expanded-year output from `Date::format_iso_week`
+/// is not accepted.
+pub fn Date::parse_iso_week(s : String) -> Date raise TempoError {
+  let v = s.view()
+  let (week_year, v) = parse_digits(v, 4)
+  let v = consume(v, '-')
+  let v = consume(v, 'W')
+  let (week, v) = parse_digits(v, 2)
+  let v = consume(v, '-')
+  let (weekday, v) = parse_digits(v, 1)
+  match v {
+    [] => ()
+    _ => raise TempoError("unexpected trailing characters")
+  }
+  Date::from_iso_week(week_year, week, weekday)
+}
+
 ///|
 /// Parse a calendar year-month in 'YYYY-MM' format.
 pub fn YearMonth::parse(s : String) -> YearMonth raise TempoError {

src/tempo_test.mbt

@@ -811,6 +811,39 @@ test "Date::from_iso_week raises on residual Int year overflow" {
   assert_true((try? @tempo.Date::from_iso_week(@int.MIN_VALUE, 1, 1)) is Err(_))
 }
 
+///|
+test "Date::parse_iso_week valid and round-trips" {
+  assert_eq(
+    @tempo.Date::parse_iso_week("2020-W53-5"),
+    @tempo.Date::new(2021, 1, 1),
+  )
+  let new_year_monday = @tempo.Date::new(2024, 1, 1)
+  assert_eq(
+    @tempo.Date::parse_iso_week(new_year_monday.format_iso_week()),
+    new_year_monday,
+  )
+  let prior_week_year = @tempo.Date::new(2021, 1, 1)
+  assert_eq(
+    @tempo.Date::parse_iso_week(prior_week_year.format_iso_week()),
+    prior_week_year,
+  )
+  let week_53_end = @tempo.Date::new(2026, 12, 31)
+  assert_eq(
+    @tempo.Date::parse_iso_week(week_53_end.format_iso_week()),
+    week_53_end,
+  )
+}
+
+///|
+test "Date::parse_iso_week rejects malformed and out-of-range input" {
+  assert_true((try? @tempo.Date::parse_iso_week("2024-W54-1")) is Err(_))
+  assert_true((try? @tempo.Date::parse_iso_week("2024-01-1")) is Err(_))
+  assert_true((try? @tempo.Date::parse_iso_week("2024-W1-1")) is Err(_))
+  assert_true((try? @tempo.Date::parse_iso_week("2024-W01")) is Err(_))
+  assert_true((try? @tempo.Date::parse_iso_week("2024-W01-8")) is Err(_))
+  assert_true((try? @tempo.Date::parse_iso_week("2024-W01-1Z")) is Err(_))
+}
+
 ///|
 test "Weekday conversion helpers" {
   assert_true(@tempo.Weekday::from_int(1) == Some(@tempo.Monday))
@@ -1213,6 +1246,35 @@ test "Date::format_ordinal" {
   )
 }
 
+///|
+test "Date::parse_ordinal valid and round-trips" {
+  assert_eq(
+    @tempo.Date::parse_ordinal("2024-060"),
+    @tempo.Date::new(2024, 2, 29),
+  )
+  let jan1 = @tempo.Date::new(2024, 1, 1)
+  assert_eq(@tempo.Date::parse_ordinal(jan1.format_ordinal()), jan1)
+  let leap_day = @tempo.Date::new(2024, 2, 29)
+  assert_eq(@tempo.Date::parse_ordinal(leap_day.format_ordinal()), leap_day)
+  let leap_dec31 = @tempo.Date::new(2024, 12, 31)
+  assert_eq(@tempo.Date::parse_ordinal(leap_dec31.format_ordinal()), leap_dec31)
+  let common_dec31 = @tempo.Date::new(2023, 12, 31)
+  assert_eq(
+    @tempo.Date::parse_ordinal(common_dec31.format_ordinal()),
+    common_dec31,
+  )
+}
+
+///|
+test "Date::parse_ordinal rejects malformed and out-of-range input" {
+  assert_true((try? @tempo.Date::parse_ordinal("2023-366")) is Err(_))
+  assert_true((try? @tempo.Date::parse_ordinal("2024-000")) is Err(_))
+  assert_true((try? @tempo.Date::parse_ordinal("2024-60")) is Err(_))
+  assert_true((try? @tempo.Date::parse_ordinal("2024-0060")) is Err(_))
+  assert_true((try? @tempo.Date::parse_ordinal("2024/060")) is Err(_))
+  assert_true((try? @tempo.Date::parse_ordinal("2024-060Z")) is Err(_))
+}
+
 ///|
 test "Date::parse roundtrip" {
   let s = "2000-02-29"