Add top level Package.swift file

[abandy]

What's Changed

Adding top level Package.swift file. Arrow and ArrowFlight are included in the top level build.

Closes #15.

[kou]

We can register this product to the Swift Package Index by this PR, right?

[abandy]

@kou Thanks for adding the issue!

[kou]

+1

Can we use this to test all targets?

For example, can we use one swift test instead of https://github.com/apache/arrow/blob/23017e3c48c1033d48674415ee4453476dc61bf3/ci/scripts/swift_test.sh#L35-L47 ?

[kou]

@abandy Should we remove Arrow/Package.swift and ArrowFlight/Package.swift because we have the top level Package.swift?

[abandy]

@abandy Should we remove Arrow/Package.swift and ArrowFlight/Package.swift because we have the top level Package.swift?

Good question. I wasn't sure if we should remove them yet as they can still be useful if a developer wants to include only Arrow and not ArrowFlight. I was thinking we would remove them once the swift package manager has added a feature for selecting only parts of a library. Please let me know what you think.

[kou]

I found https://github.com/swiftlang/swift-evolution/blob/main/proposals/0450-swiftpm-package-traits.md .
Can we use this for this use case?

[abandy]

I found https://github.com/swiftlang/swift-evolution/blob/main/proposals/0450-swiftpm-package-traits.md . Can we use this for this use case?

Yes, I see that it says it has been implemented in 6.1. Once we move to 6.1 then we should definitely take advantage of this feature!

[kou]

OK. I've opened #31 to track this.