This change adds conditional `Sendable` conformance to all
property wrapper types when their `Value` is `Sendable`, enabling
commands to be used in concurrent contexts. Some notes on
the implementation:
* Fix flag exclusivity issues
This derives the `hasUpdated` check from the parsed values data type,
rather than storing it in the closure (which breaks sendability) or
passing it through the closure invocation (which wasn't finished
enough to actually work).
* Mark all `transform` methods as `@Sendable`
This allows for a stronger, compiler-supported guarantee of
sendability when a compound `ParsableArguments` or `ParsableCommand`
type is marked `Sendable`. Most transformations shouldn't be a
problem, since the general case is that these are pure string ->
value transformations.
In cases where making such a transformation sendable is impossible,
an author can always change the property to be just a string and
perform the transformation within the context of the command's
execution, in either the `run()` or `validate()` methods.
* Add `@preconcurrency` to Sendable closure APIs
This adds the `@preconcurrency` attribute to all public APIs that
have changed to take a `@Sendable` closure. This will ease the
migration path for sendable adoption for ArgumentParser users, since
a warning will only appear for using these APIs (like the `transform`
parameter in an @Option or @Argument) once they've turned on strict
concurrency checking.
I'm also backing out changes that avoided those warnings in the tests
and examples, since in most cases those warnings are spurious;
unapplied functions don't capture state. See
https://forums.swift.org/t/pitch-inferring-sendable-for-methods-and-key-path-literals/68011
for more on this and hopefully an upcoming fix for these issues.
* Raise minimum Swift version to 5.7
In order to provide `@preconcurrency` support, the package needs to
have a minimum Swift requirement of 5.7. This makes that change and
updates the README to indicate this for the next version.
* Respect the `COLUMNS` and `LINES` environment variables, if set, when determining screen size.
* Add test for COLUMNS environment override
* Make columns test idempotent against there being a COLUMNS value already set in the environment
* Make help tests be more explicit about screen widths.
* Use existential CodingKey parameters consistently
Swift 5.7 supports implicit opening for existentials, so these
conversions from `CodingKey` parameters to pass to methods that
are generic over `CodingKey` work fine. Prior to Swift 5.7, however,
these don't compile, with the message that `CodingKey` doesn't conform
to itself.
* Bump the required Swift version for the count-lines test
The overload resolution for the `static func main()` in an `@main`
type still had issues in Swift 5.6, such that a package with a min.
platform below that which works for concurrency backdeployment doesn't
properly resolve the AsyncParsableCommand `main()` function. In
Swift 5.7, this is properly resolved, so just the availability on
the main type is sufficient.
This change just skips the test of `count-lines` prior to Swift 5.7,
so that we can maintain the open platform minimum for the package
as a whole.
- Fixes#466.
- Adds initializers to ArgumentDefinition generic over a Container type.
The Container type must conform to a new internal protocol
ArgumentDefinitionContainer which describes functionality like default
set of help options for the argument defined by the property wrapper,
etc.
- Adds overloads for Optional @Arguments and @Options with default
values which emit deprecation warning to guide users towards using the
non-Optional versions.
Adds a new `AsyncParsableCommand` protocol, which provides a
`static func main() async` entry point and can call through to the root
command's or a subcommand's asynchronous `run()` method. For this
asynchronous execution, the root command must conform to `AsyncParsableCommand`,
but its subcommands can be a mix of asynchronous and synchronous commands.
Due to an issue in Swift 5.5, you can only use `@main` on an
`AsyncParsableCommand` root command starting in Swift 5.6.
This change also includes a workaround for clients that are using Swift 5.5.
Declare a separate type that conforms to `AsyncMainProtocol` and add the `@main`
attribute to that type.
```
@main enum Main: AsyncMain {
typealias Command = <#command#>
}
```
Rauhul Varma
Lev Walkin
Gwynne Raskind
Nate Cook
Rauhul Varma