SE-0316: Global Actors

[Douglas_Gregor]

@GraysonBianco

Under the “Closures” section, is there preexisting syntax for this, or is there a typo using $i instead of i ?

callback = { @MainActor (i) in 
  print($i)
}

It's a typo, thank you! Fixed here.

@masters3d

Is there a way that nonisolated could be modeled as a global default actor that is implicit in pre actor Swift code? A default global actor for non annotated code could also address the static variables issue. Has something like this been explored ?

nonisolated should mean that it's accessible from everywhere, synchronously, so we cannot put global variables there by default. A global/static let of Sendable type could be accessed synchronously from within the module (in line with the recent amendment to SE-0306).

Mutable state cannot be nonisolated at all, unless we invent something like the nonisolated(unsafe) that was part of earlier revisions of SE-0313.

Now, we could consider putting mutable global/static variables on a specific global actor. For example, we could say that unannotated global/static variables are implicitly @MainActor, and perhaps even say that top-level code is on the main actor to reduce friction there.

Doug