(better) support for typed arrays

[mildsunrise]

See the commit messages for full change list, but basically

• Use typed arrays for output (breaking change)
• Allow typed arrays as input for GArray / GByteArray
• Validate fixed array size & element size, and fix some typos

We still need a memcpy, but transferring large data buffers should be much faster now.

[mildsunrise]

the last commit also allows accessing array fields on structs

[romgrk]

Yes, I've read the thing quickly but I have a work thing to finish by tomorrow, will be more available to review the PRs after that.

Two comments meanwhile:

• Did you have a test case for array fields? If so it would be nice to add it to the test suite
• I see some FIXME/g_assert_not_reached/g_critical. I like crashing rather than having UB, but would it be possible to use the ERROR(fmt, ...) macro for all those cases?

[mildsunrise]

wait, the struct setters work with arrays? I thought they weren't primitives and you could only get the array, not set it

edit: according to the code, plain C arrays (the only kind of arrays where length makes sense) can't be set via a struct setter since it would require memory management. so we're fine. in the future we could maybe omit memcpy entirely and this would let users modify the array elements through the typed array

[mildsunrise]

Yes, I've read the thing quickly but I have a work thing to finish by tomorrow, will be more available to review the PRs after that.

oh don't worry, the comment was just to keep track of the things in the PR. these PRs can perfectly wait :)

I'll fix the typo and the other two things you mentioned (test case and ERROR) when I find some time

[mildsunrise]

in the meanwhile I've done some improvements to the GArray -> V8 conversion, and also implemented conversion from GByteArray GValues <-> V8

I don't think there's an easy way to implement conversions for arbitrary GArrays for now, because we don't have info about the element GType