Comment by ajross
10 months ago
> But "compatibility" needs to be defined precisely.
Compatibility is defined precisely! You're definition requires scare quotes. You want to define it "Precisely" so that you can permit incompatible behavior. No one who cares about compatibility does that, it's just an excuse.
Look, other languages do this differently. Those of use using C99 booleans know we need to include a separate header to avoid colliding with the use of "bool" in pre-existing code, etc... And it sort of sucks, but it's a solved problem. I can build K&R code from 1979 on clang. Rust ignored the issue, steamrollered legacy code, and tried to sweep it under the rug with nonsense like this.
I think you are trying very hard to disagree on basic stuff that works very similarly across different language ecosystems, and (looking at other responses) that you're very angry. Disengaging.
I'll point out again that C, the poster child for ancient language technology, has been able to evolve its syntax and feature set with attention to not breaking legacy code. Excusing the lack of such attention via linguistic trickery about "defining compatibility precisely" does indeed kinda irk me. And disengaging doesn't win the argument.
The fundamental issue here is that any kind of inference can have issues on the edges. If you write code using fully qualified paths all the time, then this semver footgun can never occur.