For anyone who’re interested in continuing the work for GSoC 2023, I would like to talk about it a bit more and provide some useful takeaways for you from the GSoC 2021 work.
SwiftPM support for Swift scripts is not a Swift- or SwiftPM-only feature. It requires interoperability between the Swift compiler, compiler driver and SwiftPM — and the trickiest part is calling SwiftPM from the Swift compiler. Many community members, including me, don’t like the idea of integrating SwiftPM definitions directly into the compiler. Therefore, the feature had better be done by some kind of Swift compiler plug-in provided by SwiftPM.
2 years ago, we didn’t have a stable Swift Syntax package to use from SwiftPM, nor did we have Swift macros, so we ended up with an ugly hack in the compiler. The new reference parser implementation for this feature did the parsing in a far more elegant way, but there’re suggestions that it should be redesigned to use macros or compiler extensions (see the discussion in Pre-Pitch: `@package` argument syntax).
There’re some pieces that you may take away from previous works:
- You can refer to the syntax definition described in
@packageargument syntax. After SwiftPM 5.6 thePackageDescriptionAPIs are mostly stable, so the final syntax is very likely to resemble that pitch. - You can learn how to dynamically check for scripting mode in Swift Driver from this PR. This is used to unblock
swift <script.swift>styled calls for SwiftPM-enabled scripts without breaking existing behavior. - You may learn from the design of
swift-scripttool in this PR. The implementation may change dramatically, but some features (like quiet mode and global cache management) are useful. - Finally, you may read the GSoC 2021 writeups for this project, and try to get some inspiration:)
Welcome (again) to the Swift community and enjoy your GSoC journey😃