Swift and/or Objective-C Bindings

[GregoryComer]

🚀 The feature, motivation and pitch

From experience working with internal teams, many mobile developers prefer working with higher-level languages, when possible. It would likely benefit the user experience if we can provide Swift and/or Objective-C bindings as part of framework, likely under the Apple extension. I don't have a ton of context on developer ergonomics of calling the native C++ APIs from Swift or Objective-C, so I'll defer to the experts on this (@shoumikhin). However, given that it has been requested a few times, I think it's worth evaluating having official bindings for Swift, at least.

Alternatives

No response

Additional context

No response

RFC (Optional)

No response

cc @shoumikhin @mergennachin @byjlw

[mergennachin]

@GregoryComer - we do have such bindings as documented here: https://pytorch.org/executorch/stable/apple-runtime.html

What are the actual gaps?

cc @shoumikhin

[shoumikhin]

@mergennachin I guess @GregoryComer means bindings beyond logging. As explained in the doc, we currently support only logging APis in ObjC/Swift, and what we want eventually is such native bindings for Module and Tensor too. I've been actually working on a prototype and have it working now, so that the users can write pure Swift code like:

let module = Module(filePath: "/path/to/add.pte")
let inputs = [Tensor([2]), Tensor([3])]
let outputs = try module.forward(inputs)
XCTAssertEqual(outputs[0].tensor, Tensor([5]))

[GregoryComer]

@shoumikhin Sounds great. native Swift APIs I think would be very nice. Some internal teams have asked for this, which was the motivation for this feature request. I think it will help reduce onboarding friction for iOS devs since it seems like many devs don't want to touch C++.