[Second review] SE-0386: `package` access modifier

[taylorswift]

@stevapple

The "group" discussion brings back the question to me: What’s the real advantage of package spelling over something like @group(PackageName) (indicating internal), with SwiftPM gaining fine-grained control on whether a specific SPI can be accessed from a target?

based on this passage:

@John_McCall

The Language Workgroup is not closing off the possibility of making something like @_spi official, but we do not think it will ever be a good way to address the use pattern of closely related modules within a single codebase. Nor do we think there is a viable path to generalize @_spi to cover both use patterns; the resulting feature would be so complexly configurable that it would essentially become its own programming language, with attributes and rich interrelationships with modules.

my interpretation is the language committee believes @spi and things resembling it are a different feature from package. this implies that @spi-shaped things like @group(PackageName) are out of scope for this proposal.

in my opinion, SPM gaining fine-grained control over SPIs is less valuable (and probably more difficult to implement) than SPM gaining the ability to delimit “packages” in a more sophisticated way than “everything in this whole giant repository minus excluded targets”. it saddens me that we keep reaching for “Create New Repository” just because our build system guides us towards that sort of organization.