alt Hacker NewsHi, author of this devlog here! Not to dismiss concerns about breaking language changes, but there seems to be a bit of a misconception here that this compiler change was highly breaking and will require significant effort from Zig users to update for. Perhaps I unintentionally gave that impression in the devlog or the PR writeup, apologies if so---but it's not the case! Although there were breaking changes in this patch, they were quite minor: most users are unlikely to hit them, and if they do then they're straightforward to deal with.
For a concrete example, while testing this branch, I tried building ZLS (https://github.com/zigtools/zls/). To do that, the only change I had to make was changing `.{}` to `.empty` in a couple of its dependencies (i.e. not even in ZLS itself!). This was needed because I removed some default values from `std.ArrayList` (so the change was in standard library code rather than the language). Those default values had actually already been deprecated (with intent to remove) for around a year, so this wasn't exactly a new change either.
As another example, Andrew has updated Awebo (https://codeberg.org/awebo-chat/awebo), a text and voice chat application, to the new version of Zig. Across Awebo's entire dependency tree (which includes various packages for graphics, audio, and probably some other stuff), the full set of necessary changes was:
* Same as above, change `.{}` to `.empty` in a few places, due to removal of deprecated defaults
* Add one extra `comptime` annotation to logic which was constructing an array at comptime
* Append `orelse @alignOf(T)` onto an expression to deal with a newly-possible `null` case
These are all trivial fixes which Zig developers would be able to do pretty much on autopilot upon seeing the compile errors.
So, while there were a handful of small breaking changes, they don't seem to me like a particularly big deal (for a language where some level of breakage is still allowed). The main thing this PR achieved was instead a combination of bugfixes, and enhancements to existing features (particularly incremental compilation).
Replies
I am going to ask a question that is is definitely not the place for, but I am not involved with Zig in any way and am curious, so I hope you'll indulge me.
I noticed the following comment was added to lib/std/multi_array_list.zig [0] with this change:
/// This pointer is always aligned to the boundary `sizes.big_align`; this is not specified
/// in the type to avoid `MultiArrayList(T)` depending on the alignment of `T` because this
/// can lead to dependency loops. See `allocatedBytes` which `@alignCast`s this pointer to
/// the correct type.
[0]: https://codeberg.org/ziglang/zig/pulls/31403/files#diff-a6fc...
I made one of the comments that seems to be perceived a critical of the changes (I made a statement about the seemingly brief paragraph on changing semantics). As I replied to Andrew, I will tell you: the PR had a large amount of planning and implementation that seems of great quality. I certainly did not intend to discredit you or the obviously large amount of work you have done previously or on the change. I guess that will teach me to post without even more caveats.