# content-on-sx: Documents, blocks & collaborative editing on Smalltalk

> **DRAFT outline.** The CMS vertical — blog, WYSIWYG editor, Ghost sync. Depends
> on `persist-on-sx` (document history as an event log). Ghost/CMS sync stays a thin
> external adapter (Python/FFI) until a native replacement exists.

rose-ash's `blog` domain is content management: a block-based WYSIWYG editor,
navigation, Ghost CMS sync. A document is a tree of live blocks; editing is a
stream of operations; collaboration needs conflict-free merge. That is an object
model — blocks are objects, edits are messages, and a document is the object graph
responding to them. Smalltalk's "everything is an object responding to messages"
maps directly to a block/WYSIWYG model, and a semilattice (CRDT) merge keeps
concurrent edits conflict-free.

End-state: a Smalltalk-on-SX document model (typed blocks, structural ops),
operation log + CRDT merge for collaborative editing, versioning/history via the
event store, and a render boundary to HTML/SX. External CMS (Ghost) sync is an
injected adapter, not core.

## Status (rolling)

`bash lib/content/conformance.sh` → **196/196** (Phases 1–3 complete: blocks, doc, render, api, persist op log, CRDT merge)

## Ground rules

- **Scope:** only `lib/content/**` and `plans/content-on-sx.md`. May **import**
  from `lib/smalltalk/`, and (once it exists) `lib/persist/`. Do not edit substrates.
- **Architecture:** a document is an ordered tree of blocks (objects); an edit is a
  message (`insert`/`update`/`move`/`delete`); concurrent edits merge via a
  commutative (CRDT/semilattice) operation so order doesn't matter. History is the
  `persist` event stream; any version is a replay.
- **Determinism:** merge must be commutative + idempotent (test: apply ops in any
  order / twice → same document).
- **Commits:** one feature per commit. Progress log + tick boxes.

## Architecture sketch

```
Edit op                                 Rendered document
  (insert block after id) ...             HTML / SX tree
        │                                       ▲
        ▼                                       │
lib/content/block.sx                    lib/content/render.sx
  — typed blocks as objects               — block tree → HTML/SX
  — heading/text/image/embed              — (reuses SX render boundary)
        │                                       ▲
        ▼                                       │
lib/content/doc.sx                      lib/content/merge.sx
  — ordered block tree                    — CRDT/semilattice op merge
  — apply op, structural moves            — concurrent-edit reconciliation
        │                                       ▲
        ▼                                       │
lib/content/api.sx ── (content/edit) (content/render) (content/history) ──┐
        │                                                                  │
        ├── op log + versions → persist                                      │
        └── Ghost/CMS sync  → injected external adapter (thin, non-core) ──┘
```

## Phase 1 — Block document model
- [x] `block.sx` — typed block objects
- [x] `doc.sx` — ordered tree, apply edit op, structural moves
- [x] `render.sx` — block tree → HTML/SX
- [x] `api.sx` + tests + scoreboard + conformance.sh

## Phase 2 — Op log + versioning
- [x] edit ops as `persist` events; replay to any version
- [x] `(content/history doc)`, diff between versions

## Phase 3 — Collaborative merge (CRDT)
- [x] commutative/idempotent op merge
- [x] concurrent-edit tests (any order, double-apply → identical)

## Phase 4 — External sync + federation
- [ ] Ghost/CMS sync via injected adapter (import/export)
- [ ] federated documents (peer-authored blocks) — trust-gated stub
- [ ] tests: round-trip import/export, conflict on concurrent external edit

## Progress log

- 2026-06-07 — Phase 3 `crdt.sx` (**Phase 3 complete**): collaborative merge as
  a state-based CvRDT. Merge is a join (lub) on a semilattice → commutative,
  associative, idempotent by construction. Ordering = unique dense Logoot
  position keys (cell = (digit actor), lexicographic); presence = OR-tombstones
  (remove-wins); each field = an LWW-Register keyed by logical (ts, actor). Every
  op contributes a PARTIAL element and per-id state is their join, so
  update-/delete-before-insert are not lost. `crdt-materialize` bridges back to a
  Phase-1 `CtDoc` (sort live elements by pos → blocks). Tests prove: ops in any
  order converge, double-apply is a no-op, merge commutes/associates/is
  idempotent, concurrent inserts order deterministically, same-field LWW by
  (ts,actor), disjoint fields both survive, two divergent replicas converge both
  ways. 34 tests; suite 196/196.
- 2026-06-07 — Phase 2 `store.sx` (**Phase 2 complete**): op log + versioning
  over the persist event stream. `content/commit!` appends an edit op as a
  persist event to the doc's stream (`content:<id>`); the log is the source of
  truth. `content/head` / `content/at b id seq` replay the op stream to the
  latest / any version (materialised doc is a cache, never primary state).
  `content/history` returns per-version metadata; `content/diff` /
  `content/diff-versions` report added/removed/changed block ids. Backend is
  injected via `(persist/open)` — content knows nothing about which backend.
  Minimal persist load (event/backend/log/kv/api). 29 tests; suite 162/162.
- 2026-06-07 — Phase 1 `api.sx` (**Phase 1 complete**): `content/*` facade over
  block + doc + render. `content/bootstrap!` registers the hierarchy;
  `content/edit` applies one op or an op stream; `content/render` picks the
  boundary format ("html"/"sx" or keyword). Re-exports `content/new`,
  `content/append`, `content/insert|update|move|delete`, `content/find`, etc.
  `content/op?` distinguishes a single op from a list/block. 26 tests; suite
  133/133. content/history deferred to Phase 2 (needs the persist op log).
- 2026-06-07 — Phase 1 `render.sx`: render boundary as polymorphic message
  dispatch. Every block and `CtDoc` answers `asHTML` / `asSx`; the document
  folds children via Smalltalk `inject:into:` (works on raw SX lists), so
  `(asHTML doc)` / `(asSx doc)` are pure sends with zero type-switching in SX.
  Lists/headings render in Smalltalk source. No HTML escaping yet (noted in
  render.sx — boundary concern before untrusted content). 29 tests; suite
  107/107.
- 2026-06-06 — Phase 1 `doc.sx`: ordered block document (`CtDoc`) as a
  Smalltalk object holding an ordered block sequence. Edit ops are data dicts
  (`insert`/`update`/`move`/`delete`) with `op-*` constructors; `doc-apply` /
  `doc-apply-all` interpret an op stream, each returning a NEW document (input
  never mutated → replay-safe). Structural moves, insert-after/at, find/index,
  immutability all tested. 40 tests; suite 78/78.
- 2026-06-06 — Phase 1 `block.sx`: typed block objects as Smalltalk instances
  (`CtBlock` hierarchy: text/heading/code/quote/image/embed/divider/list).
  Type tag + accessors are message sends (polymorphic dispatch); fields are
  immutable copy-on-write via functional `st-iv-set!` (history-safe). Added
  `mk-*` constructors, `block?` predicate, `lib/content/conformance.sh` +
  scoreboard. 38/38.

## Blockers

- Smalltalk-only load chain (tokenizer/parser/runtime/eval) does **not** load
  `lib/r7rs.sx`/`spec/stdlib.sx`, so r7rs aliases (`car`/`cdr`/`null?`) are
  absent. Use base SX primitives (`first`/`rest`/`(= (len x) 0)`) in
  `lib/content/**`. Not a substrate bug — just the load surface.