Go: `Result` and `Option` type handling

[asteurer]

I'm wondering if the Option and Result handling in the Go portion would be easier to use with some changes to the API. Here's one possibility:

import (
    wit "wit_component/wit_types"
)

optionExample := wit.Some("foo")
resultExample := wit.Ok[int, error](0)

// Current implementation
if optionExample.Tag() == wit.OptionSome {
// ...
}

if resultExample.Tag() == wit.ResultErr {
// ...
}

// Suggested implementation
if optionExample.IsNone() {
// ...
}

if resultExample.IsOk() {
// ...
}

[asteurer]

@dicej Any thoughts about this?

[dicej]

Yeah, that seems reasonable for Result and Option. For variant types which have more than a few cases, being able to switch foo.Tag() { ... } is going to be way more efficient and ergonomic than if foo.IsX() { ... } else if foo.IsY() { ... } else if foo.IsZ() { ... } else ..., so I want to stick with the Tag() API in the general case. I figured we should be consistent across all variant types, including Result and Option, but I suppose that's not strictly necessary.

[asteurer]

Oh yeah, I really like how the variant type implementation works with switch statements. Do you have any concerns with keeping the Tag() API for Option and Result and just adding some helper methods to make unwrapping easier?