Nested structure as an array?

[adam900710]

Hi,

The project is really awesome for me to parsing on-disk filesystem data, it's not too complex compared to nom, but still supported nested structures.

However I am hitting a case where I have something like this in C:

struct btrfs_root_backup {
    /* Some u8/u16/u32/u64 etc. */
};

struct btrfs_super_block {
    /* Some other u8/u16/u32/u64 */
    struct btrfs_root_backup backup_roots[4];
}

In above case, how can I specify the nested rust structure for btrfs_super_block::backup_roots[4]?

Tried something like the following:

define_layout!(btrfs_super_block, LittleEndian, {
    csum: [u8; BTRFS_CSUM_SIZE],
    ... 
    super_roots: [btrfs_root_backup::NestedView; 4],
});

But of course it failed to compile.

For now I can easily workaround it by just defining super_roots into 4 members, but I'd like to know if there is any better solution.

Thanks, Qu

[smessmer]

Hi, thanks for reaching out. The only array type currently supported is [u8]. Any other array types aren't supported yet, see the README.

Nested views in arrays sound like the natural follow-up once general array types are supported. But as mentioned in the README, I likely won't have time to add this feature. But I'm willing to review and accept PRs.

[lvella]

Do you have a rough idea on how to implement arrays of primitives?

Turns out I need both: arrays of primitives and arrays of nested views.