Normative: Fix inconsistency in order of observable operations in ...FromFields() for non-ISO calendars

polyfill/lib/calendar.mjs

@@ -233,24 +233,24 @@ DefineIntrinsic('Temporal.Calendar.from', Calendar.from);
 
 impl['iso8601'] = {
   dateFromFields(fields, options, calendar) {
-    const overflow = ES.ToTemporalOverflow(options);
     fields = ES.PrepareTemporalFields(fields, ['day', 'month', 'monthCode', 'year'], ['year', 'day']);
+    const overflow = ES.ToTemporalOverflow(options);
     fields = resolveNonLunisolarMonth(fields);
     let { year, month, day } = fields;
     ({ year, month, day } = ES.RegulateISODate(year, month, day, overflow));
     return ES.CreateTemporalDate(year, month, day, calendar);
   },
   yearMonthFromFields(fields, options, calendar) {
-    const overflow = ES.ToTemporalOverflow(options);
     fields = ES.PrepareTemporalFields(fields, ['month', 'monthCode', 'year'], ['year']);
+    const overflow = ES.ToTemporalOverflow(options);
     fields = resolveNonLunisolarMonth(fields);
     let { year, month } = fields;
     ({ year, month } = ES.RegulateISOYearMonth(year, month, overflow));
     return ES.CreateTemporalYearMonth(year, month, calendar, /* referenceISODay = */ 1);
   },
   monthDayFromFields(fields, options, calendar) {
-    const overflow = ES.ToTemporalOverflow(options);
     fields = ES.PrepareTemporalFields(fields, ['day', 'month', 'monthCode', 'year'], ['day']);
+    const overflow = ES.ToTemporalOverflow(options);
     if (fields.month !== undefined && fields.year === undefined && fields.monthCode === undefined) {
       throw new TypeError('either year or monthCode required with month');
     }
@@ -1874,35 +1874,35 @@ const helperDangi = ObjectAssign({}, { ...helperChinese, id: 'dangi' });
  */
 const nonIsoGeneralImpl = {
   dateFromFields(fields, options, calendar) {
-    const overflow = ES.ToTemporalOverflow(options);
     const cache = new OneObjectCache();
     const fieldNames = this.fields(['day', 'month', 'monthCode', 'year']);
     ES.Call(ArrayPrototypeSort, fieldNames, []);
     fields = ES.PrepareTemporalFields(fields, fieldNames, []);
+    const overflow = ES.ToTemporalOverflow(options);
     const { year, month, day } = this.helper.calendarToIsoDate(fields, overflow, cache);
     const result = ES.CreateTemporalDate(year, month, day, calendar);
     cache.setObject(result);
     return result;
   },
   yearMonthFromFields(fields, options, calendar) {
-    const overflow = ES.ToTemporalOverflow(options);
     const cache = new OneObjectCache();
     const fieldNames = this.fields(['month', 'monthCode', 'year']);
     ES.Call(ArrayPrototypeSort, fieldNames, []);
     fields = ES.PrepareTemporalFields(fields, fieldNames, []);
+    const overflow = ES.ToTemporalOverflow(options);
     const { year, month, day } = this.helper.calendarToIsoDate({ ...fields, day: 1 }, overflow, cache);
     const result = ES.CreateTemporalYearMonth(year, month, calendar, /* referenceISODay = */ day);
     cache.setObject(result);
     return result;
   },
   monthDayFromFields(fields, options, calendar) {
-    const overflow = ES.ToTemporalOverflow(options);
     const cache = new OneObjectCache();
     // For lunisolar calendars, either `monthCode` or `year` must be provided
     // because `month` is ambiguous without a year or a code.
     const fieldNames = this.fields(['day', 'month', 'monthCode', 'year']);
     ES.Call(ArrayPrototypeSort, fieldNames, []);
     fields = ES.PrepareTemporalFields(fields, fieldNames, []);
+    const overflow = ES.ToTemporalOverflow(options);
     const { year, month, day } = this.helper.monthDayFromFields(fields, overflow, cache);
     // `year` is a reference year where this month/day exists in this calendar
     const result = ES.CreateTemporalMonthDay(month, day, calendar, /* referenceISOYear = */ year);

spec/calendar.html

@@ -572,8 +572,8 @@ <h1>ISODateFromFields ( _fields_, _options_ )</h1>
       </p>
       <emu-alg>
         1. Assert: Type(_fields_) is Object.
-        1. Let _overflow_ be ? ToTemporalOverflow(_options_).
         1. Set _fields_ to ? PrepareTemporalFields(_fields_, « *"day"*, *"month"*, *"monthCode"*, *"year"* », « *"year"*, *"day"* »).
+        1. Let _overflow_ be ? ToTemporalOverflow(_options_).
         1. Let _year_ be ! Get(_fields_, *"year"*).
         1. Assert: Type(_year_) is Number.
         1. Let _month_ be ? ResolveISOMonth(_fields_).
@@ -591,8 +591,8 @@ <h1>ISOYearMonthFromFields ( _fields_, _options_ )</h1>
       </p>
       <emu-alg>
         1. Assert: Type(_fields_) is Object.
-        1. Let _overflow_ be ? ToTemporalOverflow(_options_).
         1. Set _fields_ to ? PrepareTemporalFields(_fields_, « *"month"*, *"monthCode"*, *"year"* », « *"year"* »).
+        1. Let _overflow_ be ? ToTemporalOverflow(_options_).
         1. Let _year_ be ! Get(_fields_, *"year"*).
         1. Assert: Type(_year_) is Number.
         1. Let _month_ be ? ResolveISOMonth(_fields_).
@@ -612,8 +612,8 @@ <h1>ISOMonthDayFromFields ( _fields_, _options_ )</h1>
       </p>
       <emu-alg>
         1. Assert: Type(_fields_) is Object.
-        1. Let _overflow_ be ? ToTemporalOverflow(_options_).
         1. Set _fields_ to ? PrepareTemporalFields(_fields_, « *"day"*, *"month"*, *"monthCode"*, *"year"* », « *"day"* »).
+        1. Let _overflow_ be ? ToTemporalOverflow(_options_).
         1. Let _month_ be ! Get(_fields_, *"month"*).
         1. Let _monthCode_ be ! Get(_fields_, *"monthCode"*).
         1. Let _year_ be ! Get(_fields_, *"year"*).

spec/intl.html

@@ -1649,10 +1649,10 @@ <h1>Temporal.Calendar.prototype.dateFromFields ( _fields_ [ , _options_ ] )</h1>
             1. If _calendar_.[[Identifier]] is *"iso8601"*, then
               1. Let _result_ be ? ISODateFromFields(_fields_, _options_).
             1. Else,
-              1. Let _overflow_ be ? ToTemporalOverflow(_options_).
               1. Let _fieldNames_ be CalendarDateFields(_calendar_.[[Identifier]], « *"day"*, *"month"*, *"monthCode"*, *"year"* »).
               1. Sort _fieldNames_ into the same order as if an Array of the same values had been sorted using %Array.prototype.sort% with *undefined* as _comparefn_.
               1. Set _fields_ to ? PrepareTemporalFields(_fields_, _fieldNames_, « »).
+              1. Let _overflow_ be ? ToTemporalOverflow(_options_).
               1. Let _result_ be ? CalendarDateToISO(_calendar_.[[Identifier]], _fields_, _overflow_).
             1. Return ? CreateTemporalDate(_result_.[[Year]], _result_.[[Month]], _result_.[[Day]], _calendar_).
           </emu-alg>
@@ -1672,10 +1672,10 @@ <h1>Temporal.Calendar.prototype.yearMonthFromFields ( _fields_ [ , _options_ ] )
             1. If _calendar_.[[Identifier]] is *"iso8601"*, then
               1. Let _result_ be ? ISOYearMonthFromFields(_fields_, _options_).
             1. Else,
-              1. Let _overflow_ be ? ToTemporalOverflow(_options_).
               1. Let _fieldNames_ be CalendarDateFields(_calendar_.[[Identifier]], « *"month"*, *"monthCode"*, *"year"* »).
               1. Sort _fieldNames_ into the same order as if an Array of the same values had been sorted using %Array.prototype.sort% with *undefined* as _comparefn_.
               1. Set _fields_ to ? PrepareTemporalFields(_fields_, _fieldNames_, « »).
+              1. Let _overflow_ be ? ToTemporalOverflow(_options_).
               1. Let _result_ be ? CalendarDateToISO(_calendar_.[[Identifier]], _fields_, _overflow_).
               1. Set _result_.[[ReferenceISODay]] to _result_.[[Day]].
             1. Return ? CreateTemporalYearMonth(_result_.[[Year]], _result_.[[Month]], _calendar_, _result_.[[ReferenceISODay]]).