Add TC39 float16array

[autonome]

• should manually go get the caniuse identifier when not in generated draft features?
• is there a group this should be part of and where to verify? (i see in the burndown? can be generated then?)
• is the baseline status right? baseline value of false doesn't seem to be documented in either the draft contributor guide nor the baseline doc linked there
• how to handle global obj vs ctor? group them? (the burndown has separate entries)

[foolip]

Hi @autonome, thanks for this PR!

My main piece of feedback here is that we've tended to avoid features that aren't supported by any browser yet, although we do have a few such high-profile features, such as Masonry and Temporal.

From https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Float16Array#browser_compatibility it looks like this is coming in Firefox 129. The data came from mdn/browser-compat-data#23730 which I think we can trust. But if we wait until next week we'll be able to see that everything is as expected, and avoid having to update the feature if some part didn't ship.

For the feature ID and filename, I'd suggest just float16array. The "tc39-" prefix is just from the spec shortname, and unnecessary in name and identifier.

[foolip]

should manually go get the caniuse identifier when not in generated draft features?

Yes, search caniuse.com. In this case, there is no feature, so nothing to add.

is there a group this should be part of and where to verify? (i see in the burndown? can be generated then?)

Please use the typed-arrays group for this.

is the baseline status right? baseline value of false doesn't seem to be documented in either the draft contributor guide nor the baseline doc linked there

It is correct currently, because Firefox 129 hasn't been released yet. The value is documented here, and means it's not Baseline:

web-features/types.ts

Line 36 in ae7d920

/** Whether the feature is Baseline (low substatus), Baseline (high substatus), or not (false) */

how to handle global obj vs ctor? group them? (the burndown has separate entries)

Include both, and more generally anything that is a part of the feature and shipped at the same time. The reason the constructor didn't show up in the spec draft here is because the spec link in BCD is to another spec:

https://github.com/mdn/browser-compat-data/blob/b04044b8628995deac3f0fcf42e3d36e28dd9cfc/javascript/builtins/Float16Array.json#L50

That's OK, but it's still part of Float16Array.

[ddbeck]

No changes are needed here because of it, but I thought you'd be interested to know this came up in conversation on #1567 (review)

[autonome]

@Elchi3 thanks! feel free to review or just fold into your ongoing JS work, i had just picked it up as an example early on.

[Elchi3]

Thanks @autonome! I think we're good to go with this one! 👍