Add @time.fixed_zone_unvalidated

[gmlewis]

This function is needed so that a default @time.Zone can be passed to a function (other than utc_zone).

Another name for this could be fixed_zone_or_utc if fixed_zone_unvalidated is not wanted.

It fixed problems like this:

[peter-jerry-ye]

Sorry but I didn't fully understand the context of this PR.

Is the unvalidated needed for performance issue or does the current validation reject any inputs that you find valid? And what does 'default @time.Zone' should be?

[gmlewis]

Sorry but I didn't fully understand the context of this PR.

Is the unvalidated needed for performance issue or does the current validation reject any inputs that you find valid? And what does 'default @time.Zone' should be?

I'm trying to write a function with a default parameter of type @time.Zone.
However, because it has !Error, the compiler will not let me do it.
See screenshot above. Does that make sense?

In other words, I can't write this:

///| Returns the current time.
pub fn get_current_time(
  /// now is optional so we can mock time in tests
  now~ : @wallClock.Datetime = @wallClock.now(),
  zone~ : @time.Zone = @time.fixed_zone!("America/New_York", -5 * 60 * 60)
) -> @time.ZonedDateTime!Error {
  @time.unix!(now.seconds.reinterpret_as_int64(), zone~)
}

However, because @time.fixed_zone!(...) has a ! in it, the compiler won't let me.

Am I doing something wrong?

[peter-jerry-ye]

How about this:

///| Returns the current time.
pub fn get_current_time(
  /// now is optional so we can mock time in tests
  now~ : @wallClock.Datetime = @wallClock.now(),
  zone? : @time.Zone
) -> @time.ZonedDateTime!Error {
  let zone = zone.or(@time.fixed_zone!("America/New_York", -5 * 60 * 60))
  @time.unix!(now.seconds.reinterpret_as_int64(), zone~)
}

[gmlewis]

Yes, that would work, but now zone must be passed to the function.
Is there any way to call get_current_time() without any parameters and have it default to a particular time zone, yet allow the caller to override the time zone in the function call with a named zone~ parameter?

[peter-jerry-ye]

uh, a ?: T is an optional parameter. Why do you have to pass a parameter?

Maybe you want to check this: https://docs.moonbitlang.com/en/latest/language/fundamentals.html#optional-arguments

[gmlewis]

Oh, wow, OK. I guess I need to go back and read all the docs again, as I'm forgetting parts of the language.

Thank you, @peter-jerry-ye !

Closing.