Reference for stage-3 float16array #33652

Josh-Cena · 2024-05-17T07:16:54Z

Part of #33561.

cc @hamishwillee maybe you want to review this.

cc @zloirock I cannot find a polyfill link for Float16Array itself and I assume that's intentional.

For whoever is reviewing this: please watch out for any copy/paste remnants since they are mostly copy/pasted...

github-actions · 2024-05-17T07:18:19Z

Preview URLs (16 pages)

Flaws (5)

Note! 11 documents with no flaws that don't need to be listed. 🎉

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView/getFloat16
Title: DataView.prototype.getFloat16()
Flaw count: 1

bad_bcd_queries:
- No BCD data for query: javascript.builtins.DataView.getFloat16

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView/setFloat16
Title: DataView.prototype.setFloat16()
Flaw count: 1

bad_bcd_queries:
- No BCD data for query: javascript.builtins.DataView.setFloat16

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/Float16Array
Title: Float16Array
Flaw count: 1

bad_bcd_queries:
- No BCD data for query: javascript.builtins.Float16Array

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/Float16Array/Float16Array
Title: Float16Array() constructor
Flaw count: 1

bad_bcd_queries:
- No BCD data for query: javascript.builtins.Float16Array.Float16Array

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/f16round
Title: Math.f16round()
Flaw count: 1

bad_bcd_queries:
- No BCD data for query: javascript.builtins.Math.f16round

External URLs (10)

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView/getFloat16
Title: DataView.prototype.getFloat16()

https://github.com/zloirock/core-js (1 time) (Note! This may be a new URL 👀)

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView/setFloat16
Title: DataView.prototype.setFloat16()

https://github.com/zloirock/core-js (1 time) (Note! This may be a new URL 👀)

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/Float16Array
Title: Float16Array

https://github.com/huggingface/blog/blob/main/stable_diffusion.md (1 time) (Note! This may be a new URL 👀)
https://github.com/w3c/ColorWeb-CG/blob/main/canvas_float.md (1 time) (Note! This may be a new URL 👀)

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray
Title: TypedArray

https://en.wikipedia.org/wiki/IEEE_754 (1 time) (Note! This may be a new URL 👀)

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/Math
Title: Math

https://en.wikipedia.org/wiki/Half-precision_floating-point_format (1 time) (Note! This may be a new URL 👀)
https://en.wikipedia.org/wiki/Single-precision_floating-point_format (1 time) (Note! This may be a new URL 👀)

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/fround
Title: Math.fround()

https://en.wikipedia.org/wiki/Single-precision_floating-point_format (2 times) (Note! This may be a new URL 👀)

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/f16round
Title: Math.f16round()

https://en.wikipedia.org/wiki/Half-precision_floating-point_format (2 times) (Note! This may be a new URL 👀)
https://github.com/zloirock/core-js (1 time) (Note! This may be a new URL 👀)

(comment last updated: 2024-05-21 00:21:56)

zloirock · 2024-05-17T08:35:41Z

I cannot find a polyfill link for Float16Array itself and I assume that's intentional.

Yes, because of some specific issues I delayed adding Float16Array till reworking the architecture and dropping support of some old engines or accepting stage 4 for this proposal. The rest methods from this proposal were added to core-js.

files/en-us/web/javascript/reference/global_objects/dataview/getfloat16/index.md

hamishwillee · 2024-05-20T01:19:38Z

files/en-us/web/javascript/reference/global_objects/dataview/getfloat16/index.md

+
+The **`getFloat16()`** method of {{jsxref("DataView")}} instances reads 2 bytes starting at the specified byte offset of this `DataView` and interprets them as a 16-bit floating point number. There is no alignment constraint; multi-byte values may be fetched from any offset within bounds.
+
+{{EmbedInteractiveExample("pages/js/dataview-getfloat16.html")}}


This isn't rendering - I presume is "in progress"?

PR number please

mdn/interactive-examples#2781

files/en-us/web/javascript/reference/global_objects/dataview/getfloat16/index.md

hamishwillee · 2024-05-20T01:34:16Z

files/en-us/web/javascript/reference/global_objects/dataview/setfloat16/index.md

+const buffer = new ArrayBuffer(10);
+const dataview = new DataView(buffer);
+dataview.setFloat16(0, 3);
+dataview.getFloat16(1); // 0


Wouldn't it be more useful to show setting and getting the same buffer index?

Yeah, that somewhat feels trivial to me though.

So the question is, what does someone learn from having the getter in an example in the setter?

From this they could learn "by default the buffer is zero filled", which is interesting but requires a little thinking. It feels odd and pointless.

In the getFloat16() example you arbitrarily-sh populate the array and then get the float. This returns a value 0.00001537799835205078 which is kind of cool because it shows that the input values aren't trivially encoded into a real number. But it is also frustrating, because you can't look at the inputs and say "hey, that's the right output".

So when I saw this, I thought - ah, cool, I can see that the value in and out do match. It would be even better if I could see the values in the buffer as bytes too, but.

Anyway, those are my reasons why I would either delete the getter or make it get a value that you set.

We are not fetching the default zero-filled value here. We are setting the 0th byte and 1st byte and then reading the 1st and 2nd byte. It just happens that we read out the value 0.

I didn't notice that, so what does that tell you about the example?

Obviously you don't want to change this, and its a small speck in otherwise excellent docs so I'll merge.

files/en-us/web/javascript/guide/typed_arrays/index.md

files/en-us/web/javascript/reference/global_objects/math/f16round/index.md

hamishwillee · 2024-05-20T01:51:36Z

Looks great. Just a few editorial type questions.

files/en-us/web/javascript/reference/global_objects/math/index.md

files/en-us/web/javascript/reference/global_objects/math/f16round/index.md

hamishwillee · 2024-05-21T00:22:41Z

files/en-us/web/javascript/reference/global_objects/math/index.md

@@ -43,51 +43,53 @@ Unlike most global objects, `Math` is not a constructor. You cannot use it with
 ## Static methods

 - {{jsxref("Math.abs()")}}
- - : Returns the absolute value of `x`.
+ - : Returns the absolute value of the input.


FYI @Josh-Cena I replaced x by "the input" (or similar) for all the other cases in the math parent page. Left a few log/exponential cases where the use of x, y is more useful.

hamishwillee

Approving, but see comments - such as PR for the interactive examples.

hamishwillee · 2024-06-03T00:22:28Z

Thanks very much for sorting this out.

Josh-Cena requested a review from a team as a code owner May 17, 2024 07:16

Josh-Cena requested review from teoli2003 and removed request for a team May 17, 2024 07:16

github-actions bot added Content:JS JavaScript docs size/m 51-500 LoC changed labels May 17, 2024

Reference for stage-3 float16array

07d447a

Josh-Cena force-pushed the float16array branch from ffe2347 to 07d447a Compare May 17, 2024 07:19