1973064 - Require strict matching with a precise ZonedDateTime offset

Status: ASSIGNED

(Core :: JavaScript: Standard Library, task)

Description

[André Bargull [:anba]]

Implement the changes from https://github.com/tc39/proposal-temporal/pull/3107.

Comment 1

[André Bargull [:anba]]

Attachment: Bug 1973064 - Part 1: Change time zone representation in ParsedZonedDateTime. r=#spidermonkey-reviewers!

Part 2 needs another bool flag to track if an offset time zone has sub-minute
precision. Adding this flag directly to ParsedZonedDateTime leads to the
following possible states:

1. ParsedZonedDateTime::hasOffset is true, then
   a. ParsedZonedDateTime::timeZoneOffset contains the offset.
   b. ParsedZonedDateTime::hasOffsetSubminutePrecision is true if the offset
   has sub-minute precision. Otherwise the field is false.
   c. ParsedZonedDateTime::isUTC is always false.
2. ParsedZonedDateTime::isUTC is true, then
   a. ParsedZonedDateTime::timeZoneOffset is unused.
   b. ParsedZonedDateTime::hasOffsetSubminutePrecision is unused.
   c. ParsedZonedDateTime::hasOffset is always false.
3. ParsedZonedDateTime::hasOffset and ParsedZonedDateTime::isUTC are false,
   a. ParsedZonedDateTime::timeZoneOffset is unused.
   b. ParsedZonedDateTime::hasOffsetSubminutePrecision is unused.
4. And other combination is an invalid state.

This approach has the downside that it's possible to create invalid states and
it's not directly clear which flag controls which other fields are active. Using
MaybeOneOf avoids these issues.

Comment 2

[André Bargull [:anba]]

Attachment: Bug 1973064 - Part 2: Require strict matching with a precise ZonedDateTime offset. r=#spidermonkey-reviewers!

Implement the actual changes from https://github.com/tc39/proposal-temporal/pull/3107.