Apple's Swift 4 road map focuses on ABI, concurrency
Apple hasn't even delivered its Swift 3 language yet and already is getting an early thumbs-up from developers for planned Swift 4 follow-ups, which will focus on application binary interface (ABI) stability, concurrency, and scripting.
In a recent post on the swift-evolution mailing list on swift-org, Apple's Chris Lattner, senior director of developer tools, said Swift 4 was due in fall 2017, with Swift 3.x set to arrive next spring. Swift was introduced as an eventual successor to Objective-C in June 2014.
Stage 1 development in Swift 4 will prioritize source stability as well as resilience, enabling public APIs to evolve over time even with ABI stability. "For example, we don't want the C++ 'fragile base class' problem to ever exist in Swift," Lattner said.
