Function deser_substring

crates/ixon/src/metadata.rs:398–407

(
  buf: &mut &[u8],
  ixon_env: &super::env::Env,
)

    for univ in &self.meta_univs {
      put_univ(univ, buf);
    }
    // Level-spelling patches (canonicity §10.6): per entry, Tag0
    // arena_idx, Tag0 len, Tag0 virtual univ indices.
    put_vec_len(self.univ_patches.len(), buf);
    for patch in &self.univ_patches {
      Tag0::new(patch.arena_idx).put(buf);
      put_vec_len(patch.univ_idxs.len(), buf);
      for idx in &patch.univ_idxs {
        Tag0::new(*idx).put(buf);
      }
    }
    Ok(())
  }