remove observable calls to "from"

docs/cookbook/stockExchangeTimeZone.mjs

@@ -131,17 +131,6 @@ class NYSETimeZone extends Temporal.TimeZone {
 
 const tzNYSE = Object.freeze(new NYSETimeZone());
 
-// Monkeypatch Temporal.TimeZone.from to handle our custom time zone
-let oldTzFrom;
-const replacement = (item) => {
-  if (item === 'NYSE') return tzNYSE;
-  return oldTzFrom.call(Temporal.TimeZone, item);
-};
-if (Temporal.TimeZone.from !== replacement) {
-  oldTzFrom = Temporal.TimeZone.from;
-  Temporal.TimeZone.from = replacement;
-}
-
 let zdt;
 let isOpen;
 let date;
@@ -165,16 +154,16 @@ assert.equal(date.toString(), '2020-11-12');
 
 // 2. Is the stock market open on a particular date?
 date = Temporal.PlainDate.from('2020-11-12');
-isOpen = date.toZonedDateTime('NYSE').toPlainDate().equals(date);
+isOpen = date.toZonedDateTime(tzNYSE).toPlainDate().equals(date);
 assert.equal(isOpen, true);
 date = Temporal.PlainDate.from('2020-11-14');
-isOpen = date.toZonedDateTime('NYSE').toPlainDate().equals(date);
+isOpen = date.toZonedDateTime(tzNYSE).toPlainDate().equals(date);
 assert.equal(isOpen, false);
 
 // 3. For a particular date, when is the next market day?
 const getNextMarketDay = (date) => {
   date = Temporal.PlainDate.from(date);
-  const zdt = date.toZonedDateTime('NYSE');
+  const zdt = date.toZonedDateTime(tzNYSE);
   if (zdt.toPlainDate().equals(date)) {
     // It's a market day, so find the next one
     return zdt.add({ days: 1 }).toPlainDate();
@@ -195,22 +184,22 @@ assert.equal(newDate.equals('2020-11-16'), true);
 // If it's closed, then when will it open next?
 // Return a result in the local time zone, not NYC's time zone.
 zdt = Temporal.ZonedDateTime.from('2020-11-12T18:50-08:00[America/Los_Angeles]');
-inNYSE = zdt.withTimeZone('NYSE');
-isOpen = inNYSE.toPlainDateTime().toZonedDateTime('NYSE').equals(inNYSE);
+inNYSE = zdt.withTimeZone(tzNYSE);
+isOpen = inNYSE.toPlainDateTime().toZonedDateTime(tzNYSE).equals(inNYSE);
 assert.equal(isOpen, false);
 nextOpen = inNYSE.timeZone.getNextTransition(zdt.toInstant()).toZonedDateTimeISO(zdt.timeZone);
 assert.equal(nextOpen.toString(), '2020-11-13T06:30:00-08:00[America/Los_Angeles]');
 
 zdt = Temporal.ZonedDateTime.from('2020-11-12T12:50-08:00[America/Los_Angeles]');
-inNYSE = zdt.withTimeZone('NYSE');
-isOpen = inNYSE.toPlainDateTime().toZonedDateTime('NYSE').equals(inNYSE);
+inNYSE = zdt.withTimeZone(tzNYSE);
+isOpen = inNYSE.toPlainDateTime().toZonedDateTime(tzNYSE).equals(inNYSE);
 assert.equal(isOpen, true);
 todayClose = inNYSE.timeZone.getNextTransition(zdt.toInstant()).toZonedDateTimeISO(zdt.timeZone);
 assert.equal(todayClose.toString(), '2020-11-12T13:00:00-08:00[America/Los_Angeles]');
 
 // 5. For any particular market date, what were the opening and closing clock times in NYC?
 date = Temporal.PlainDate.from('2020-11-09');
-openInstant = date.toZonedDateTime('NYSE').toInstant();
-closeInstant = date.toZonedDateTime('NYSE').timeZone.getNextTransition(openInstant);
+openInstant = date.toZonedDateTime(tzNYSE).toInstant();
+closeInstant = date.toZonedDateTime(tzNYSE).timeZone.getNextTransition(openInstant);
 assert.equal(openInstant.toZonedDateTimeISO('America/New_York').toPlainTime().toString(), '09:30:00');
 assert.equal(closeInstant.toZonedDateTimeISO('America/New_York').toPlainTime().toString(), '16:00:00');

polyfill/lib/calendar.mjs

@@ -153,21 +153,7 @@ export class Calendar {
     return ES.ToString(this);
   }
   static from(item) {
-    if (ES.Type(item) === 'Object') {
-      if (!('calendar' in item)) return item;
-      item = item.calendar;
-      if (ES.Type(item) === 'Object' && !('calendar' in item)) return item;
-    }
-    const stringIdent = ES.ToString(item);
-    if (IsBuiltinCalendar(stringIdent)) return new Calendar(stringIdent);
-    let calendar;
-    try {
-      ({ calendar } = ES.ParseISODateTime(stringIdent, { zoneRequired: false }));
-    } catch {
-      throw new RangeError(`Invalid calendar: ${stringIdent}`);
-    }
-    if (!calendar) calendar = 'iso8601';
-    return new Calendar(calendar);
+    return ES.CalendarFrom(item, this);
   }
 }
 
@@ -2000,6 +1986,6 @@ impl['gregory'] = ObjectAssign({}, nonIsoGeneralImpl, { helper: helperGregory })
 
 const BUILTIN_CALENDAR_IDS = Object.keys(impl);
 
-function IsBuiltinCalendar(id) {
+export function IsBuiltinCalendar(id) {
   return ArrayIncludes.call(BUILTIN_CALENDAR_IDS, id);
 }

polyfill/lib/ecmascript.mjs

@@ -62,6 +62,7 @@ import {
   MICROSECONDS,
   NANOSECONDS
 } from './slots.mjs';
+import { IsBuiltinCalendar } from './calendar.mjs';
 
 const DAYMILLIS = 86400000;
 const NS_MIN = bigInt(-86400).multiply(1e17);
@@ -1481,7 +1482,7 @@ export const ES = ObjectAssign({}, ES2020, {
         calendar
       } = ES.ParseTemporalZonedDateTimeString(ES.ToString(item)));
       if (!ianaName) throw new RangeError('time zone ID required in brackets');
-      timeZone = ES.TimeZoneFrom(ianaName);
+      timeZone = ES.TimeZoneFrom(ianaName, GetIntrinsic('%Temporal.TimeZone%'));
       if (!calendar) calendar = ES.GetISO8601Calendar();
       calendar = ES.ToTemporalCalendar(calendar);
     }
@@ -1513,17 +1514,22 @@ export const ES = ObjectAssign({}, ES2020, {
     const TemporalCalendar = GetIntrinsic('%Temporal.Calendar%');
     return new TemporalCalendar('iso8601');
   },
-  CalendarFrom: (calendarLike) => {
-    const TemporalCalendar = GetIntrinsic('%Temporal.Calendar%');
-    let from = TemporalCalendar.from;
-    if (from === undefined) {
-      from = GetIntrinsic('%Temporal.Calendar.from%');
+  CalendarFrom: (item, constructor) => {
+    if (ES.Type(item) === 'Object') {
+      if (!('calendar' in item)) return item;
+      item = item.calendar;
+      if (ES.Type(item) === 'Object' && !('calendar' in item)) return item;
     }
-    const calendar = ES.Call(from, TemporalCalendar, [calendarLike]);
-    if (ES.Type(calendar) !== 'Object') {
-      throw new TypeError('Temporal.Calendar.from should return an object');
+    const stringIdent = ES.ToString(item);
+    if (IsBuiltinCalendar(stringIdent)) return new constructor(stringIdent);
+    let calendar;
+    try {
+      ({ calendar } = ES.ParseISODateTime(stringIdent, { zoneRequired: false }));
+    } catch {
+      throw new RangeError(`Invalid calendar: ${stringIdent}`);
     }
-    return calendar;
+    if (!calendar) calendar = 'iso8601';
+    return new constructor(calendar);
   },
   CalendarFields: (calendar, fieldNames) => {
     const fields = ES.GetMethod(calendar, 'fields');
@@ -1633,7 +1639,7 @@ export const ES = ObjectAssign({}, ES2020, {
       return calendarLike;
     }
     const identifier = ES.ToString(calendarLike);
-    return ES.CalendarFrom(identifier);
+    return ES.CalendarFrom(identifier, GetIntrinsic('%Temporal.Calendar%'));
   },
   CalendarCompare: (one, two) => {
     const cal1 = ES.ToString(one);
@@ -1674,20 +1680,23 @@ export const ES = ObjectAssign({}, ES2020, {
     if (!ES.IsTemporalMonthDay(result)) throw new TypeError('invalid result');
     return result;
   },
-  TimeZoneFrom: (temporalTimeZoneLike) => {
-    const TemporalTimeZone = GetIntrinsic('%Temporal.TimeZone%');
-    let from = TemporalTimeZone.from;
-    if (from === undefined) {
-      from = GetIntrinsic('%Temporal.TimeZone.from%');
+  TimeZoneFrom: (item, constructor) => {
+    if (ES.Type(item) === 'Object') {
+      if (!('timeZone' in item)) return item;
+      item = item.timeZone;
+      if (ES.Type(item) === 'Object' && !('timeZone' in item)) return item;
     }
-    return ES.Call(from, TemporalTimeZone, [temporalTimeZoneLike]);
+    const timeZone = ES.TemporalTimeZoneFromString(ES.ToString(item));
+    const result = new constructor(timeZone);
+    if (!ES.IsTemporalTimeZone(result)) throw new TypeError('invalid result');
+    return result;
   },
   ToTemporalTimeZone: (temporalTimeZoneLike) => {
     if (ES.Type(temporalTimeZoneLike) === 'Object') {
       return temporalTimeZoneLike;
     }
     const identifier = ES.ToString(temporalTimeZoneLike);
-    return ES.TimeZoneFrom(identifier);
+    return ES.TimeZoneFrom(identifier, GetIntrinsic('%Temporal.TimeZone%'));
   },
   TimeZoneCompare: (one, two) => {
     const tz1 = ES.ToString(one);

polyfill/lib/timezone.mjs

@@ -143,18 +143,9 @@ export class TimeZone {
     return ES.ToString(this);
   }
   static from(item) {
-    if (ES.Type(item) === 'Object') {
-      if (!('timeZone' in item)) return item;
-      item = item.timeZone;
-      if (ES.Type(item) === 'Object' && !('timeZone' in item)) return item;
-    }
-    const timeZone = ES.TemporalTimeZoneFromString(ES.ToString(item));
-    const result = new this(timeZone);
-    if (!ES.IsTemporalTimeZone(result)) throw new TypeError('invalid result');
-    return result;
+    return ES.TimeZoneFrom(item, this);
   }
 }
 
 MakeIntrinsicClass(TimeZone, 'Temporal.TimeZone');
-DefineIntrinsic('Temporal.TimeZone.from', TimeZone.from);
 DefineIntrinsic('Temporal.TimeZone.prototype.getOffsetNanosecondsFor', TimeZone.prototype.getOffsetNanosecondsFor);

polyfill/test/Instant/prototype/toZonedDateTime/calendar-from-undefined.js

@@ -7,9 +7,7 @@ includes: [compareArray.js]
 ---*/
 
 const actual = [];
-const expected = [
-  "get Temporal.Calendar.from",
-];
+const expected = [];
 
 const instant = Temporal.Instant.from("1975-02-02T14:25:36.123456789Z");
 const dateTime = Temporal.PlainDateTime.from("1963-07-02T12:34:56.987654321");
@@ -30,13 +28,6 @@ const timeZone = new Proxy({
   },
 });
 
-Object.defineProperty(Temporal.Calendar, "from", {
-  get() {
-    actual.push("get Temporal.Calendar.from");
-    return undefined;
-  },
-});
-
 const result = instant.toZonedDateTime({ timeZone, calendar: "japanese" });
 assert.sameValue(result.epochNanoseconds, instant.epochNanoseconds);
 assert.sameValue(result.calendar instanceof Temporal.Calendar, true);