Slate v2 Gap Matrix

Purpose

This file tracks the major unresolved gaps surfaced by the Slate issue corpus and ongoing comparison research.

It is the missing bridge between:

• issue pressure
• package proofs already completed
• external architecture references still worth studying

The goal is not to dump every bug family into one list.

The goal is to keep a disciplined answer to:

1. what gap is still structurally unresolved?
2. which package should own it?
3. which reference repos are most likely to teach us something useful?
4. is it a slate-v2 priority now, a later slate-v2 concern, or really a plate-v2 concern?

Status Key

• proved
• structural-next
• research-next
• later
• better-fit-for-plate-v2

Gap Matrix

1. Decorations, Marks, And Annotation Anchors

Status: research-next

Primary package owners:

• slate-react-v2
• slate-v2
• secondarily slate-dom-v2

Why it matters:

• render-time mark projection
• decoration invalidation breadth
• cross-node decoration semantics
• annotation/comment anchors on selections

Current evidence:

• issue cluster explicitly names this as a recurrent cross-cutting seam in issue-clusters.md
• direct issue pressure includes #5987, #3354, #3352, #3383, #2465, #4477

Current proof status:

• slate-react-v2 proves selector-first runtime and id-backed subscriptions
• it does not yet prove decoration or annotation projection

Best references to analyze:

1. Lexical
2. ProseMirror
3. Tiptap
4. current slate-react

Likely fit:

• adopt-later-for-slate-v2

Notes after research:

• Lexical strengthens the case for explicit update payloads and renderer discipline, but not for dropping useSyncExternalStore.

2. Invisible Nodes, Zero-Width Sentinels, And DOM Selection Anchors

Status: research-next

Primary package owners:

• slate-dom-v2
• slate-v2

Why it matters:

• Slate still relies on DOM-visible anchor hacks for selection
• empty blocks and inline boundaries need legal caret positions
• the current DOM layer still pays for invisible node strategy choices

Current evidence:

• #1971
• #2597
• #5760
• #4839
• #6034

Current proof status:

• slate-dom-v2 proves identity-backed DOM lookup and editor containment
• it does not yet prove a replacement for the current invisible-node / zero-width strategy

Best references to analyze:

1. Slate
2. ProseMirror
3. Lexical
4. edix
5. EditContext API

Likely fit:

• adopt-later-for-slate-v2

Notes after research:

• EditContext is promising because it decouples text input from DOM mutation.
• But it does not auto-solve selection mapping, accessibility, spellcheck, clipboard, or undo.
• So it is a later input-boundary candidate, not a silver bullet for the current DOM/selection seam.

3. Clipboard Fragment Ownership And External Format Boundaries

Status: structural-next

Primary package owners:

• slate-dom-v2
• slate-v2

Why it matters:

• internal fragment format ownership
• editor identity across copy/paste
• HTML/plaintext import/export seams
• avoiding accidental data-slate-fragment coupling

Current evidence:

• #5233
• #5328
• #5630
• #1024
• #4440

Current proof status:

• not yet structurally proved
• this is the next missing Phase 4 seam

Best references to analyze:

1. ProseMirror
2. edix
3. Tiptap
4. current slate-dom

Likely fit:

• adopt-now-for-slate-v2

Notes after research:

• ProseMirror is the strongest direct reference here because clipboard lives in its view package and exposes explicit serializer/parser transform hooks.
• Edix is still valuable because it makes internal clipboard ownership explicit with a minimal adapter seam.

4. Pagination, Layout, And Deterministic Measurement

Status: better-fit-for-plate-v2

Primary package owners:

• future plate-v2
• maybe future higher-layer layout packages

Why it matters:

• page-aware composition
• deterministic layout measurement
• pagination without DOM-reflow roulette

Current evidence:

• issue pressure like #5944
• wider known demand for page-layout editing

Current proof status:

• intentionally not in the current slate-v2 proof stack

Best references to analyze:

1. Pretext
2. Premirror
3. ProseMirror only as document truth substrate

Likely fit:

• better-fit-for-plate-v2

Notes after research:

• Pretext is the strongest measurement reference here because its prepare -> layout split gives deterministic text sizing without DOM reflow.
• Premirror is the strongest architecture reference here because it keeps document truth, measurement, composition, and rendering as separate layers.
• The combined lesson is blunt: pagination belongs above slate-v2, not inside the core/runtime packages.

5. Virtualization And Huge-Document Rendering

Status: research-next

Primary package owners:

• slate-react-v2
• maybe future plate-v2 view layers

Why it matters:

• very large documents
• initial render cost
• offscreen rendering strategy
• interaction between virtualization and DOM lookup

Current evidence:

• #790
• #4056
• #5216
• #5131
• existing benchmark lanes in benchmark-candidate-map.md

Current proof status:

• selector-first runtime and id-based DOM lookup are proved
• virtualization itself is not

Best references to analyze:

1. Lexical
2. ProseMirror
3. Pretext / Premirror
4. edix only as a lightweight contrast

Likely fit:

• split:
  • adopt-later-for-slate-v2 for renderer fundamentals
  • better-fit-for-plate-v2 for full productized huge-doc experiences

Notes after research:

• Lexical is the strongest next reference for renderer invalidation discipline and update metadata.
• Pretext matters here too because deterministic text height unlocks better occlusion and scroll-anchor stability without DOM measurement thrash.
• Premirror suggests page/layout snapshots and mapping indexes are the right kind of prerequisite if virtualization ever grows page-aware, but that still smells more like plate-v2 than near-term Slate core work.

6. Plugin / Extension Architecture

Status: research-next

Primary package owners:

• slate-v2
• plate-v2

Why it matters:

• Slate still wants a cleaner plugin story than wrapper soup
• Plate likely wants a richer product-layer extension surface than Slate core should carry

Current evidence:

• current package proofs intentionally deferred the full plugin model

Current proof status:

• not structurally proved yet

Best references to analyze:

1. ProseMirror
2. Tiptap
3. Lexical
4. urql
5. current Plate

Notes after research:

• ProseMirror already proves a serious state/plugin boundary with filterTransaction, appendTransaction, and plugin-owned state fields.
• That strengthens the case for later Slate middleware evolution, but richer extension ergonomics still fit Plate better than Slate core.
• Lexical adds a strong extension dependency graph and builder model, which is more likely to influence plate-v2 than the next slate-v2 package seam.
• Premirror adds a useful high-layer precedent: feature bundles that package schema extensions, commands, invalidation, and rendering helpers together without pretending they belong in document core.
• Tiptap makes the same product-layer point from the opposite angle: packaging, extension catalogs, and wrapper DX can make an editor feel fast without changing the underlying engine story much.
• urql adds the strongest pipeline discipline here: explicit exchange contracts, sync-first ordering, and a hard rule against silently dropping unknown operations.
• VS Code adds the strongest provider-registry discipline here: per-feature registries, scored provider selection, explicit host RPC, and adaptive feature debouncing.

8. Update Metadata And Dirty-Signal Discipline

Status: research-next

Primary package owners:

• slate-react-v2
• slate-history-v2

Why it matters:

• change tags
• dirty element/leaf summaries
• filtering update reactions without broad rerenders
• history grouping and onChange semantics that are explicit, not guessed

Current evidence:

• our proofs are still thinner here than Lexical’s model

Best references to analyze:

1. Lexical
2. ProseMirror

Likely fit:

• adopt-later-for-slate-v2

Likely fit:

• split:
  • adopt-later-for-slate-v2 for core middleware seams
  • better-fit-for-plate-v2 for rich extension UX

Notes after research:

• Tiptap adds a useful runtime caution: selector subscriptions in a dedicated React package are good, but carrying broad compatibility baggage is exactly what we are allowed to avoid with the slate-react-v2 React 19.2+ choice.

7. Service / Semantic Layer Architecture

Status: better-fit-for-plate-v2

Primary package owners:

• plate-v2

Why it matters:

• semantic linting
• AI analyzers
• completions
• diagnostics
• document reasoning services

Best references to analyze:

1. VS Code
2. Language Server Protocol
3. TanStack DB
4. urql

Likely fit:

• better-fit-for-plate-v2

Notes after research:

• TanStack DB is the strongest current reference for semantic projections: normalized collections, explicit indexes, and incremental live-query compilation.
• urql is the strongest current reference for execution pipelines: one client hub, many exchanges, strict ordering rules.
• VS Code is the strongest current reference for tool-side feature hosting: text model separate from view, per-feature registries, explicit host boundaries.
• LSP is the strongest current reference for external semantic-service contracts: versioned text sync, capability negotiation, cancellable requests, pull diagnostics, and lazy resolve flows.
• The combined lesson is strong: if plate-v2 grows a semantic-service layer, it should probably look like normalized projection stores plus exchange-like execution stages, with per-feature registries and protocol-shaped service boundaries instead of ad hoc plugin soup.

9. Lightweight Editable Surfaces

Status: research-next

Primary package owners:

• plate-v2

Why it matters:

• not every editable needs the full Slate package stack
• code-like, plaintext, or token-input surfaces want much smaller APIs
• forcing Slate onto tiny text surfaces is how architecture gets bloated

Current proof status:

• no dedicated lightweight-surface strategy exists yet

Best references to analyze:

1. use-editable
2. rich-textarea
3. markdown-editor

Likely fit:

• better-fit-for-plate-v2

Notes after research:

• use-editable is the current lower bound: a tiny hook, mutation rollback, selection repair, and a plain-text-first API.
• That is useful product pressure for plate-v2.
• It is not a reason to collapse slate-v2 into DOM-owned text editing.
• rich-textarea is the strongest positive reference in this lane: native textarea truth plus mirrored decoration layer is a much cleaner fit for lightweight text surfaces.
• markdown-editor is mostly the cautionary example: manual contenteditable projection with character-count and layout invariants gets brittle fast.
• Open UI Richer Text Fields is the strongest platform direction for this lane: InputRange, CSS highlights, suggestions, and mask primitives would let many “rich enough” surfaces stay native.
• If those primitives land, more cases should stay out of Slate entirely.

What Is Already Proved

These should stay out of the gap list unless new evidence reopens them:

• slate-v2 transaction-first core
• slate-dom-v2 identity-backed DOM lookup and containment
• slate-react-v2 selector-first runtime and controlled replacement
• slate-history-v2 transaction-aware undo units

Next Research Order

To improve this matrix honestly:

1. final slate-v2 synthesis
2. explicit plate-v2 action memo

That order keeps pressure on the unresolved product and extension seams without drifting into random repo tourism.