Migrate NonISOCalendarDateToISO

Author: sffc

spec.emu

@@ -729,7 +729,7 @@ contributors: Google, Ecma International
       </h1>
       <dl class="header">
         <dt>description</dt>
-        <dd>It produces the year relative to the epoch year (the arithmetic year) for a given set of era, eraYear for a calendar that has eras.</dd>
+        <dd>It produces the year relative to the epoch year (the arithmetic year) for a given set of _era_, _eraYear_ in _calendar_, a calendar that includes an era named _era_.</dd>
       </dl>
       <emu-alg>
         1. Let _era_ be CanonicalizeEraInCalendar(_calendar_, _era_).
@@ -902,16 +902,19 @@ contributors: Google, Ecma International
       <p>This definition supersedes the definition provided in <emu-xref href="#sec-temporal-nonisodateadd"></emu-xref>.</p>
       <p>It performs the following steps when called:</p>
       <emu-alg>
-        1. Let _yearMonth_ be RegulateNonISOYearMonth(_calendar_, _isoDate_, _duration_.[[Years]]).
+        1. Let _parts_ be CalendarISOToDate(_calendar_, _baseDate_).
+        1. Let _yearMonth_ be RegulateNonISOYearMonth(_calendar_, _parts_.[[Year]], _parts_.[[MonthCode]], _duration_.[[Years]]).
         1. Let _endOfMonth_ be BalanceNonISODate(_calendar_, _yearMonth_.[[Year]], _yearMonth_.[[Month]] + _duration_.[[Months]] + 1, 0).
-        1. Let _baseDay_ be CalendarISOToDate(_calendar_, _isoDate_).[[Day]].
+        1. Let _baseDay_ be _parts_.[[Day]].
         1. If _endOfMonth_.[[Day]] &lt; _baseDay_, then
           1. If _overflow_ is ~reject~, throw a *RangeError* exception.
           1. Let _regulatedDay_ be _endOfMonth_.[[Day]].
         1. Else,
           1. Let _regulatedDay_ be _baseDay_.
         1. Let _balancedDate_ be BalanceNonISODate(_calendar_, _endOfMonth_.[[Year]], _endOfMonth_.[[Month]], _regulatedDay_ + 7 * _duration_.[[Weeks]] + _duration_.[[Days]]).
-        1. Return ? CalendarDateArithmeticalToISO(_calendar_, _balancedDate_.[[Year]], _balancedDate_.[[Month]], _balancedDate_.[[Day]]).
+        1. Let _result_ be ? CalendarDateArithmeticalToISO(_calendar_, _balancedDate_.[[Year]], _balancedDate_.[[Month]], _balancedDate_.[[Day]]).
+        1. If ISODateWithinLimits(_result_) is *false*, throw a *RangeError* exception.
+        1. Return _result_.
       </emu-alg>
     </emu-clause>
 
@@ -963,51 +966,42 @@ contributors: Google, Ecma International
       </emu-alg>
     </emu-clause>
 
-    <emu-clause id="sup-temporal-isvalidmonthcodeforcalendarinyear" type="implementation-defined abstract operation">
+    <emu-clause id="sup-temporal-monthcodetoarithmeticalmonth" type="implementation-defined abstract operation">
       <h1>
-        IsValidMonthCodeForCalendarInYear (
+        MonthCodeToArithmeticalMonth (
           _calendar_: a calendar type that is not *"iso8601"*,
           _year_: an integer,
           _monthCode_: a String,
-        ): an Boolean
+        ): an integer or ~invalid~
       </h1>
       <dl class="header">
         <dt>description</dt>
         <dd>
-          It interprets _year_ as arithmetical value in the given _calendar_ and returns *true* if there is a month with the given _monthCode_ in that year or *false* otherwise.
+          It interprets _year_ as arithmetical year in the given _calendar_, returning an integer if there is a month with the given _monthCode_ in that year, or ~invalid~ otherwise.
         </dd>
       </dl>
       <p>It performs the following steps when called:</p>
       <emu-alg>
         1. If IsValidMonthCodeForCalendar(_calendar_, _monthCode_) is *false*, then
-          1. Return *false*.
+          1. Return ~invalid~.
         1. Let _monthCodeParts_ be ParseMonthCode(_monthCode_).
-        1. If _monthCodeParts_.[[IsLeap]] is *false*, then
-          1. Return *true*.
-        1. Assert: _calendar_ is one of *"chinese"*, *"dangi"*, or *"hebrew"*.
-        1. Return a calendar-dependent Boolean as described above.
-      </emu-alg>
-    </emu-clause>
-
-    <emu-clause id="sup-temporal-calendardatecodestoiso" type="implementation-defined abstract operation">
-      <h1>
-        CalendarDateCodesToISO (
-          _calendar_: a calendar type that is not *"iso8601"*,
-          _year_: an integer,
-          _monthCode_: a String,
-          _day_: an integer,
-        ): either a normal completion containing an ISO Date Record or a throw completion
-      </h1>
-      <dl class="header">
-        <dt>description</dt>
-        <dd>
-          It returns an ISO Date Record that, when converted to a Calendar Date Record with _calendar_ (for example, with CalendarISOToDate), contains the given _year_, _monthCode_, and _day_ values in its [[Year]], [[MonthCode]], and [[Day]] fields. If this is not possible, a RangeError is thrown.
-        </dd>
-      </dl>
-      <p>It performs the following steps when called:</p>
-      <emu-alg>
-        1. If _year_, _monthCode_, and _day_ do not form a valid date in _calendar_, throw a RangeError exception.
-        1. Return a calendar-dependent ISO Date Record as described above.
+        1. If _calendar_ is not *"chinese"*, *"dangi"*, or *"hebrew"*, then
+          1. Return _monthCodeParts_.[[Number]].
+        1. Let _monthsBefore_ be 0.
+        1. Let _number_ be 1.
+        1. Let _isLeap_ be *false*.
+        1. Repeat, while _number_ &le; 12,
+          1. Let _intermediate_ be CreateMonthCode(_number_, _isLeap_).
+          1. If _calendar_ contains _monthCode_ in _year_, according to a calendar-dependent algorithm, then
+            1. Set _monthsBefore_ to _monthsBefore_ + 1.
+          1. If _monthCodeParts_.[[Number]] is _number_ and _monthCodeParts.[[IsLeap]] is _isLeap_, then
+            1. Return _monthsBefore_.
+          1. If _isLeap_ is *false*, then
+            1. Set _isLeap_ to *true*.
+          1. Else,
+            1. Set _isLeap_ to *false*.
+            1. Set _number_ to _number_ + 1.
+        1. Return ~invalid~.
       </emu-alg>
     </emu-clause>
 
@@ -1076,7 +1070,8 @@ contributors: Google, Ecma International
       <h1>
         RegulateNonISOYearMonth (
           _calendar_: a calendar type that is not *"iso8601"*,
-          _isoDate_: an ISO Date Record,
+          _arithmeticalYear_: an integer,
+          _monthCode_: a String,
           _years_: an integer,
         ): a Record with fields [[Year]] (an integer) and [[Month]] (an integer)
       </h1>
@@ -1088,25 +1083,26 @@ contributors: Google, Ecma International
       </dl>
       <p>It performs the following steps when called:</p>
       <emu-alg>
-        1. Let _y1_ be CalendarDateArithmeticYear(_calendar_, _isoDate_).
-        1. Let _d1_ be CalendarISOToDate(_calendar_, _isoDate_).
-        1. Let _monthCode_ be _d1_.[[MonthCode]].
-        1. Let _y2_ be _y1_ + _years_.
+        1. Let _y2_ be _arithmeticalYear_ + _years_.
         1. If _calendar_ is *"chinese"*, *"dangi"*, or *"hebrew"*, then
           1. If _calendar_ is *"chinese"* or *"dangi"*, then
-            1. If IsValidMonthCodeForCalendarInYear(_calendar_, _y2_, _monthCode_) is *false*, then
-              1. Set _monthCode_ to CreateMonthCode(ParseMonthCode(_monthCode_).[[Number]], *false*).
+            1. Let _month_ be MonthCodeToArithmeticalMonth(_calendar_, _y2_, _monthCode_).
+            1. If _month_ is ~invalid~, then
+              1. Let _monthCode_ be CreateMonthCode(ParseMonthCode(_monthCode_).[[Number]], *false*).
+              1. Set _month_ to MonthCodeToArithmeticalMonth(_calendar_, _y2_, _monthCode_).
+              1. Assert: _month_ is not ~invalid~.
           1. Else,
             1. Assert: _calendar_ is *"hebrew"*.
-            1. Let _d2_ be CalendarISOToDate(_calendar_, ! CalendarDateCodesToISO(_calendar_, _y2_, *"M01"*, 1)).
-            1. If _d1_.[[InLeapYear]] is *true* and _d2_.[[InLeapYear]] is *false*, then
+            1. Let _isLeap1_ be *true* if _arithmeticalYear_ is a leap year in the Hebrew calendar, or *false* otherwise.
+            1. Let _isLeap2_ be *true* if _y2_ is a leap year in the Hebrew calendar, or *false* otherwise.
+            1. If _isLeap1_ is *true* and _isLeap2_ is *false*, then
               1. If _monthCode_ is *"M05L"*, then
                 1. Set _monthCode_ to *"M06"*.
-            1. Else if _d1_.[[InLeapYear]] is *false* and _d2_.[[InLeapYear]] is *true*, then
+            1. Else if _isLeap1_ is *false* and _isLeap2_ is *true*, then
               1. If _monthCode_ is *"M06"*, then
                 1. Set _monthCode_ to *"M05L"*.
-          1. Assert: IsValidMonthCodeForCalendarInYear(_calendar_, _y2_, _monthCode_) is *true*.
-          1. Let _month_ be CalendarISOToDate(_calendar_, ! CalendarDateCodesToISO(_calendar_, _y2_, _monthCode_, 1)).[[Month]].
+            1. Let _month_ be MonthCodeToArithmeticalMonth(_calendar_, _monthCode_, _y2_).
+            1. Assert: _month_ is not ~invalid~.
         1. Else,
           1. Let _month_ be ParseMonthCode(_monthCode_).[[Number]].
         1. Return the Record { [[Year]]: _y2_, [[Month]]: _month_ }.
@@ -1186,9 +1182,10 @@ contributors: Google, Ecma International
       </dl>
       <p>It performs the following steps when called:</p>
       <emu-alg>
-        1. Let _yearMonth_ be RegulateNonISOYearMonth(_calendar_, _baseDate_, _years_).
+        1. Let _parts_ be CalendarISOToDate(_calendar_, _baseDate_).
+        1. Let _yearMonth_ be RegulateNonISOYearMonth(_calendar_, _parts_.[[Year]], _parts_.[[MonthCode]], _years_).
         1. Let _endOfMonth_ be BalanceNonISODate(_calendar_, _yearMonth_.[[Year]], _yearMonth_.[[Month]] + _months_ + 1, 0).
-        1. Let _baseDay_ be CalendarISOToDate(_calendar_, _baseDate_).[[Day]].
+        1. Let _baseDay_ be _parts_.[[Day]].
         1. If _weeks_ is not 0 or _days_ is not 0, then
           1. If _baseDay_ &lt; _endOfMonth_.[[Day]], then
             1. Let _regulatedDay_ be _baseDay_.
@@ -1282,16 +1279,31 @@ contributors: Google, Ecma International
       <p>This definition supersedes the definition provided in <emu-xref href="#sec-temporal-nonisocalendardatetoiso"></emu-xref>.</p>
       <p>It performs the following steps when called:</p>
       <emu-alg>
-        1. If _fields_.[[Era]] and _fields_.[[EraYear]] are not ~unset~ and IsValidEraYearForCalendar(_calendar_, _fields_.[[Era]], _fields_.[[EraYear]]) is *false*, throw a *RangeError* exception.
-        1. If _fields_.[[MonthCode]] is not ~unset~ and IsValidMonthCodeForCalendar(_calendar_, _fields_.[[MonthCode]]) is *false*, throw a *RangeError* exception.
-        1. If _fields_ describes an existing date in _calendar_, return an implementation-defined ISO Date Record that corresponds to the date described by _fields_.
-        1. If _overflow_ is ~reject~, throw a *RangeError* exception.
-        1. (This step only matters for lunisolar calendars.) If _fields_.[[MonthCode]] is a leap month that doesn't exist in the year, then:
-          1. Set _fields_ to another date according to the cultural conventions of that calendar's users. Of the currently supported calendars: if _calendar_ is *"chinese"* or *"dangi"*, change _fields_.[[MonthCode]] to the same month code but without the *"L"*. If _calendar_ is *"hebrew"*, change _fields_.[[MonthCode]] from *"M05L"* to *"M06"*.
-          1. Update _fields_.[[Month]] accordingly.
-        1. If _fields_.[[MonthCode]] is a valid month code for _fields_.[[Year]], but the date described by _fields_ does not exist, set _fields_.[[Day]] to the closest day in the same month. If there are two equally-close dates in the same month, pick the later one.
-        1. (This step does not apply to any currently supported calendars.) If the date described by _fields_ still does not exist, set _fields_ to the closest date in the same year. If there are two equally-close dates in that year, pick the later one.
-        1. Return an implementation-defined ISO Date Record that corresponds to the date described by _fields_.
+        1. If _fields_.[[Era]] and _fields_.[[EraYear]] are not ~unset~, then
+          1. If IsValidEraYearForCalendar(_calendar_, _fields_.[[Era]], _fields_.[[EraYear]]) is *false*, throw a *RangeError* exception.
+          1. Let _year_ be CalendarDateArithmeticYearForEraYear(_calendar_, _fields_.[[Era]], _fields_.[[EraYear]]).
+        1. Else,
+          1. Assert: _fields_.[[Year]] is not ~unset~.
+          1. Let _year_ be _fields_.[[Year]].
+        1. If _fields_.[[MonthCode]] is not ~unset~, then
+          1. If IsValidMonthCodeForCalendar(_calendar_, _fields_.[[MonthCode]]) is *false*, throw a *RangeError* exception.
+          1. If _overflow_ is ~reject~, then
+            1. Let _month_ be MonthCodeToArithmeticalMonth(_calendar_, _year_, _fields_.[[MonthCode]]).
+            1. If _month_ is ~invalid~, throw a *RangeError* exception.
+          1. Else,
+            1. Let _month_ be RegulateNonISOYearMonth(_calendar_, _year_, _monthCode_, 0).[[Month]].
+        1. Else,
+          1. Assert: _fields_.[[Month]] is not ~unset~.
+          1. Let _month_ be _fields_.[[Month]].
+        1. Let _day_ be _fields_.[[Day]].
+        1. Assert: _day_ is not ~unset~.
+        1. Let _daysInMonth_ be CalendarDaysInMonth(_calendar_, _year_, _month_).
+        1. If _daysInMonth_ &le; _day_, then
+          1. If _overflow_ is ~reject~, throw a *RangeError* exception.
+          1. Let _regulatedDay_ be _daysInMonth_.
+        1. Else,
+          1. Let _regulatedDay_ be _day_.
+        1. Return ? CalendarDateArithmeticalToISO(_calendar_, _year_, _month_, _day_).
       </emu-alg>
     </emu-clause>