WIP: Create time zone record from time zone objects

Similar to calendar records, when constructing a new ZonedDateTime, eagerly get all the required time zone methods, and save them in a Record, which goes into the ZonedDateTime's [[TimeZoneRecord]] internal slot. _For internal use of the intrinsic ZonedDateTime constructor only_, in the polyfill the constructor accepts a time zone record object instead of a Temporal.TimeZone object. This has no observable effect on user code, because user code can never obtain a time zone record object. Still to do: - spec text - same problem as calendar records where the time zone record is lost when calling through user code - when calling a TimeZone method directly, we create a new time zone record first, which Gets all the methods. Maybe this isn't needed unless we're calling the method from ZonedDateTime where we have the record? See: #1294
tc39 · Mar 2, 2021 · bcf869a · bcf869a
1 parent 05cd622
commit bcf869a
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Showing 45 changed files with 370 additions and 310 deletions.
diff --git a/.eslintrc.yml b/.eslintrc.yml
@@ -101,6 +101,7 @@ overrides:
       assert: readonly
       verifyProperty: readonly
       MINIMAL_CALENDAR_OBJECT: readonly
+      MINIMAL_TIME_ZONE_OBJECT: readonly
     # test262 code complies to a different coding style
     extends: 'eslint:recommended'
     rules:

diff --git a/polyfill/lib/ecmascript.mjs b/polyfill/lib/ecmascript.mjs
diff --git a/polyfill/lib/intl.mjs b/polyfill/lib/intl.mjs
@@ -13,7 +13,7 @@ import {
   ISO_MICROSECOND,
   ISO_NANOSECOND,
   CALENDAR_RECORD,
-  TIME_ZONE
+  TIME_ZONE_RECORD
 } from './slots.mjs';
 import { TimeZone } from './timezone.mjs';
 
@@ -47,7 +47,7 @@ export function DateTimeFormat(locale = IntlDateTimeFormat().resolvedOptions().l
   this[TZ_GIVEN] = options.timeZone ? options.timeZone : null;
 
   this[ORIGINAL] = new IntlDateTimeFormat(locale, options);
-  this[TZ_RESOLVED] = new TimeZone(this.resolvedOptions().timeZone);
+  this[TZ_RESOLVED] = ES.NewTimeZoneRecord(new TimeZone(this.resolvedOptions().timeZone));
   this[CAL_ID] = this.resolvedOptions().calendar;
   this[DATE] = new IntlDateTimeFormat(locale, dateAmend(options));
   this[YM] = new IntlDateTimeFormat(locale, yearMonthAmend(options));
@@ -368,8 +368,8 @@ function extractOverrides(temporalObj, main) {
       );
     }
 
-    let timeZone = GetSlot(temporalObj, TIME_ZONE);
-    const objTimeZone = ES.ToString(timeZone);
+    let timeZoneRecord = GetSlot(temporalObj, TIME_ZONE_RECORD);
+    const objTimeZone = ES.TimeZoneToString(timeZoneRecord);
     if (main[TZ_GIVEN] && main[TZ_GIVEN] !== objTimeZone) {
       throw new RangeError(`timeZone option ${main[TZ_GIVEN]} doesn't match actual time zone ${objTimeZone}`);
     }

diff --git a/polyfill/lib/now.mjs b/polyfill/lib/now.mjs
@@ -19,17 +19,19 @@ function instant() {
 }
 function plainDateTime(calendarLike, temporalTimeZoneLike = timeZone()) {
   const timeZone = ES.ToTemporalTimeZone(temporalTimeZoneLike);
+  const timeZoneRecord = ES.NewTimeZoneRecord(timeZone);
   const calendar = ES.ToTemporalCalendar(calendarLike);
   const calendarRecord = ES.NewCalendarRecord(calendar);
   const inst = instant();
-  return ES.BuiltinTimeZoneGetPlainDateTimeFor(timeZone, inst, calendarRecord);
+  return ES.BuiltinTimeZoneGetPlainDateTimeFor(timeZoneRecord, inst, calendarRecord);
 }
 function plainDateTimeISO(temporalTimeZoneLike = timeZone()) {
   const timeZone = ES.ToTemporalTimeZone(temporalTimeZoneLike);
+  const timeZoneRecord = ES.NewTimeZoneRecord(timeZone);
   const calendar = ES.GetISO8601Calendar();
   const calendarRecord = ES.NewCalendarRecord(calendar);
   const inst = instant();
-  return ES.BuiltinTimeZoneGetPlainDateTimeFor(timeZone, inst, calendarRecord);
+  return ES.BuiltinTimeZoneGetPlainDateTimeFor(timeZoneRecord, inst, calendarRecord);
 }
 function zonedDateTime(calendarLike, temporalTimeZoneLike = timeZone()) {
   const timeZone = ES.ToTemporalTimeZone(temporalTimeZoneLike);

diff --git a/polyfill/lib/plaindate.mjs b/polyfill/lib/plaindate.mjs
@@ -355,18 +355,12 @@ export class PlainDate {
   toZonedDateTime(item) {
     if (!ES.IsTemporalDate(this)) throw new TypeError('invalid receiver');
 
-    let timeZone, temporalTime;
+    let timeZoneRecord, temporalTime;
     if (ES.Type(item) === 'Object') {
-      let timeZoneLike = item.timeZone;
-      if (timeZoneLike === undefined) {
-        timeZone = ES.ToTemporalTimeZone(item);
-      } else {
-        timeZone = ES.ToTemporalTimeZone(timeZoneLike);
-        temporalTime = item.plainTime;
-      }
-    } else {
-      timeZone = ES.ToTemporalTimeZone(item);
+      timeZoneRecord = ES.GetOrCreateTimeZoneRecord(item);
+      if (timeZoneRecord) temporalTime = item.plainTime;
     }
+    if (!timeZoneRecord) timeZoneRecord = ES.NewTimeZoneRecord(ES.ToTemporalTimeZone(item));
 
     const year = GetSlot(this, ISO_YEAR);
     const month = GetSlot(this, ISO_MONTH);
@@ -402,9 +396,9 @@ export class PlainDate {
       nanosecond,
       calendarRecord
     );
-    const instant = ES.BuiltinTimeZoneGetInstantFor(timeZone, dt, 'compatible');
+    const instant = ES.BuiltinTimeZoneGetInstantFor(timeZoneRecord, dt, 'compatible');
     const ZonedDateTime = GetIntrinsic('%Temporal.ZonedDateTime%');
-    return new ZonedDateTime(GetSlot(instant, EPOCHNANOSECONDS), timeZone, calendarRecord);
+    return new ZonedDateTime(GetSlot(instant, EPOCHNANOSECONDS), timeZoneRecord, calendarRecord);
   }
   toPlainYearMonth() {
     if (!ES.IsTemporalDate(this)) throw new TypeError('invalid receiver');

diff --git a/polyfill/lib/plaindatetime.mjs b/polyfill/lib/plaindatetime.mjs
@@ -728,11 +728,12 @@ export class PlainDateTime {
   toZonedDateTime(temporalTimeZoneLike, options = undefined) {
     if (!ES.IsTemporalDateTime(this)) throw new TypeError('invalid receiver');
     const timeZone = ES.ToTemporalTimeZone(temporalTimeZoneLike);
+    const timeZoneRecord = ES.NewTimeZoneRecord(timeZone);
     options = ES.NormalizeOptionsObject(options);
     const disambiguation = ES.ToTemporalDisambiguation(options);
-    const instant = ES.BuiltinTimeZoneGetInstantFor(timeZone, this, disambiguation);
+    const instant = ES.BuiltinTimeZoneGetInstantFor(timeZoneRecord, this, disambiguation);
     const ZonedDateTime = GetIntrinsic('%Temporal.ZonedDateTime%');
-    return new ZonedDateTime(GetSlot(instant, EPOCHNANOSECONDS), timeZone, GetSlot(this, CALENDAR_RECORD));
+    return new ZonedDateTime(GetSlot(instant, EPOCHNANOSECONDS), timeZoneRecord, GetSlot(this, CALENDAR_RECORD));
   }
   toPlainDate() {
     if (!ES.IsTemporalDateTime(this)) throw new TypeError('invalid receiver');

diff --git a/polyfill/lib/plaintime.mjs b/polyfill/lib/plaintime.mjs
@@ -461,7 +461,7 @@ export class PlainTime {
     if (timeZoneLike === undefined) {
       throw new TypeError('missing timeZone property');
     }
-    const timeZone = ES.ToTemporalTimeZone(timeZoneLike);
+    const timeZoneRecord = ES.NewTimeZoneRecord(ES.ToTemporalTimeZone(timeZoneLike));
 
     const year = GetSlot(temporalDate, ISO_YEAR);
     const month = GetSlot(temporalDate, ISO_MONTH);
@@ -487,9 +487,9 @@ export class PlainTime {
       nanosecond,
       calendarRecord
     );
-    const instant = ES.BuiltinTimeZoneGetInstantFor(timeZone, dt, 'compatible');
+    const instant = ES.BuiltinTimeZoneGetInstantFor(timeZoneRecord, dt, 'compatible');
     const ZonedDateTime = GetIntrinsic('%Temporal.ZonedDateTime%');
-    return new ZonedDateTime(GetSlot(instant, EPOCHNANOSECONDS), timeZone, calendarRecord);
+    return new ZonedDateTime(GetSlot(instant, EPOCHNANOSECONDS), timeZoneRecord, calendarRecord);
   }
   getISOFields() {
     if (!ES.IsTemporalTime(this)) throw new TypeError('invalid receiver');

diff --git a/polyfill/lib/record.mjs b/polyfill/lib/record.mjs
@@ -42,3 +42,13 @@ export class CalendarRecord {
     this.toString = requireCallable(calendar, 'toString');
   }
 }
+
+export class TimeZoneRecord {
+  constructor(timeZone) {
+    if (Type(timeZone) !== 'Object') throw new TypeError('time zone must be an object');
+    this.object = timeZone;
+    this.getOffsetNanosecondsFor = requireCallable(timeZone, 'getOffsetNanosecondsFor');
+    this.getPossibleInstantsFor = requireCallableOrUndefined(timeZone, 'getPossibleInstantsFor');
+    this.toString = requireCallable(timeZone, 'toString');
+  }
+}
diff --git a/polyfill/lib/slots.mjs b/polyfill/lib/slots.mjs
@@ -22,7 +22,7 @@ export const MONTH_DAY_BRAND = 'slot-month-day-brand';
 
 // ZonedDateTime
 export const INSTANT = 'slot-cached-instant';
-export const TIME_ZONE = 'slot-time-zone';
+export const TIME_ZONE_RECORD = 'slot-time-zone-record';
 
 // Duration
 export const YEARS = 'slot-years';

diff --git a/polyfill/lib/timezone.mjs b/polyfill/lib/timezone.mjs
@@ -55,19 +55,22 @@ export class TimeZone {
   }
   getOffsetStringFor(instant) {
     instant = ES.ToTemporalInstant(instant, GetIntrinsic('%Temporal.Instant%'));
-    return ES.BuiltinTimeZoneGetOffsetStringFor(this, instant);
+    const timeZoneRecord = ES.NewTimeZoneRecord(this);
+    return ES.BuiltinTimeZoneGetOffsetStringFor(timeZoneRecord, instant);
   }
   getPlainDateTimeFor(instant, calendar = ES.GetISO8601Calendar()) {
     instant = ES.ToTemporalInstant(instant, GetIntrinsic('%Temporal.Instant%'));
     calendar = ES.ToTemporalCalendar(calendar);
+    const timeZoneRecord = ES.NewTimeZoneRecord(this);
     const calendarRecord = ES.NewCalendarRecord(calendar);
-    return ES.BuiltinTimeZoneGetPlainDateTimeFor(this, instant, calendarRecord);
+    return ES.BuiltinTimeZoneGetPlainDateTimeFor(timeZoneRecord, instant, calendarRecord);
   }
   getInstantFor(dateTime, options = undefined) {
     dateTime = ES.ToTemporalDateTime(dateTime, GetIntrinsic('%Temporal.PlainDateTime%'));
     options = ES.NormalizeOptionsObject(options);
     const disambiguation = ES.ToTemporalDisambiguation(options);
-    return ES.BuiltinTimeZoneGetInstantFor(this, dateTime, disambiguation);
+    const timeZoneRecord = ES.NewTimeZoneRecord(this);
+    return ES.BuiltinTimeZoneGetInstantFor(timeZoneRecord, dateTime, disambiguation);
   }
   getPossibleInstantsFor(dateTime) {
     if (!ES.IsTemporalTimeZone(this)) throw new TypeError('invalid receiver');