No Virtual DOM: Compose bypasses tree-diffing entirely. It uses a Slot Table — a linear, positionally indexed runtime structure backed by a positional ledger.
The State Engine: The Snapshot System acts like an MVCC database, isolating state reads/writes and notifying the Recomposer when tracked reads are invalidated.
Smart Skipping: If inputs match and are compiler-verified as Stable, Compose skips the block. Skipping isn’t completely free; the Composer still validates metadata and advances its slot pointer.
Targeted Blast Radius: Recomposition boundaries (Restart Groups) use anchors to resume traversal exactly where an invalidation occurred, sparing the rest of the layout tree.
1. The Slot Table: A Linear, Positionally Indexed Structure
A common misconception is that Compose works like React’s Virtual DOM by generating a secondary UI tree and diffing it against the old one. Instead, Compose relies on a single, flat, linear data structure called the Slot Table.
