Review round 3, on the round-2 primitive itself. One lesson covers all
three findings: a rope write is only half of an edit, and "discard
history" means whichever history the buffer actually has.
P1 — the binding swallowed the edit. `set_generated_contents` returned
`()`, so nothing reached `notify_buffer_edit_to_windows`. Two
consequences, both reproduced by the reviewer. In the default build a
window showing the buffer kept a `TextView` line index describing the
PREVIOUS contents, and the next paint indexed the new rope with stale
ranges — `assertion failed: end <= self.len()` in `src/rope.rs`. In the
CRDT build `pending_crdt_ops` stayed empty, so replica mirrors never
imported the owner's write and their optimistic edits were generated
against content already replaced. The `delete`+`insert` pair this
replaced had done that fan-out for free.
Now applies ONE whole-buffer `Replace`, returns its `Edit`, and notifies
from the binding. The doc comment states the obligation, because the
next owner to adopt the primitive inherits it.
P2 — "discard history" was false in CRDT mode. The v0.1 stacks are
bypassed entirely there; the history lives in loro's `UndoManager`.
`read_only` stops the replay but not the retention, which is the memory
cost the contract claims to eliminate. `UndoManager` exposes no clear,
but needs none: it records only what happens after it is constructed,
the same property `CrdtState::from_bytes` already uses to keep the seed
insert out of undo. `CrdtState::clear_undo_history` rebinds a fresh
manager to the same doc.
P2 — the docs described the pre-fix architecture. Q#TC6a said no Lua
binding sets `read_only` and round-trip input is the only guard; the
acceptance text still said `is_read_only() == false` while 16b had been
flipped to true; `terminal.lua`'s comment repeated the obsolete claim.
The architecture is layered and now says so: rope-level read-only
protects the daemon copy, round-trip input protects the replica's
optimistic mirror, and neither substitutes for the other. Q#TC6a keeps
its analysis under a superseded-in-part box rather than being silently
rewritten — its conclusion survives, two of its premises do not.
New pins. acc16d paints the window after a SHRINKING generated write:
stale offsets then point past the buffer end, so the failure is the
reported crash rather than merely stale pixels. acc16e asserts the
refresh is queued for mirrors, through the real copy-mode path;
`crdt`-gated and therefore dark in CI, which is why 16d drives the
binding rather than the terminal. Plus a CRDT unit test that ten renders
leave the `UndoManager` with nothing recorded.
Bites: dropping the notify panics acc16d at `rope.rs:145` and fails
acc16e with `queued: []`; dropping the `UndoManager` rebind fails the
new unit test on `can_undo`.
Still open, and recorded in COHERENCE.md §14: the fan-out obligation
makes `*compilation*`/listview adoption more than a one-line swap.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016gGQC6eqHJVbZJ5Hg7aLer
Levi Neuwirth
a0fb01f24c