Feature request: ArrayView should have all the public methods that Array has

[gmlewis]

Discord discussion: https://discord.com/channels/1135479745207869510/1285600688197341287

Since it is not easy to create an Array from an ArrayView without copying, it would be nice if ArrayView could do everything that an Array can do.

Additionally, I often find myself in similar situations with these types that are closely related yet frequently incompatible without copying:

• Bytes
• FixedArray[Byte]
• Array[Byte]
• ArrayView[Byte]

Ideally, it should be easy to convert to/from any of these 4 types to any of the other 4 types WITHOUT any copying.

[peter-jerry-ye]

The without any copying part is impossible to give guarantee.

For example, take the wasm-gc backend. There's possibility that Bytes and FixedArray[Byte] can be converted back and forth with array<u8>, but impossible with Array[Byte].

On the other hand, there's no difference between FixedArray and Array and JS native array. But still, it's impossible to convert ArrayView to Array without copying.

[gmlewis]

Thank you, @peter-jerry-ye, for the information.

Is it safe to say that anything that takes an Array as an argument would be more useful if it instead took an ArrayView?

For example, take Bytes::from_array:

Instead of:

pub fn Bytes::from_array(arr : Array[Byte]) -> Bytes { ... }

wouldn't it be more flexible if it were this?

pub fn Bytes::from_array(arr : ArrayView[Byte]) -> Bytes { ... }

And if that is true, would you want to make sweeping breaking API changes throughout the code base, or would you prefer two versions of every function where the Array version would call the (more flexible) ArrayView version?
(Or maybe instead deprecate the existing one and add a new one?)

If I were to take on this "good first issue", would it be OK to address it with baby-steps like this first Array/ArrayView step?

[peter-jerry-ye]

@gmlewis That's a good question. ArrayView is indeed more general than Array. We may need to take that into account. cc @bobzhang @Yoorkin