ecs 0.2.3: World.Table and spawnTables, readonly: true; @adobe/ecs-gpu and @adobe/ecs-persistence publishable

ecs/CLAUDE.md

@@ -34,6 +34,12 @@ conversation, the diff or the alternatives. Tell them what it is and what it doe
   - "X, not B, C or D": say what is done;
   - "previously", "now", "instead of", "moved from", "whose source of truth is…".
 
+## Layout
+
+A feature's or package's root folder holds only its public exports, one file per export, named after it, and their
+tests. Its implementation lives in folders below. Nothing outside a feature imports below its root, and within a
+package only its entry file re-exports.
+
 ## Never use top-level await
 
 Do not use `await` at module top level in any package's sources. Defer async work to a lazy-init pattern: store the
@@ -63,7 +69,9 @@ Standard script names a package may define:
   every package's `pages`.
 
 Publishing is governed only by the `private` field: `pnpm -r publish` publishes every package with `private: false` and
-skips the rest. Every package sets `private` explicitly, and samples are `private: true`. Don't add a `publish-public`
+skips the rest. Every package sets `private` explicitly. Samples are `private: true`, and every library is published
+publicly from the start: `private: false`, `publishConfig` with `"access": "public"`, `independentVersion: true`, and
+`LICENSE` among its files, as `ecs-gpu`'s are. Don't add a `publish-public`
 or similar script. `scripts/check-workspace-conventions.mjs` (`pnpm run check:workspace`, run in CI) enforces these.
 
 ## Checks

ecs/README.md

@@ -7,6 +7,8 @@ A high-performance, multithreaded Entity Component System for web-based applicat
 - **[`@adobe/ecs`](packages/ecs)**: the ECS and its build plugin, `@adobe/ecs/compiler`.
 - **[`@adobe/ecs-gpu`](packages/ecs-gpu)**: WebGPU devices, canvases, render targets, views and frame passes for the
   ECS.
+- **[`@adobe/ecs-persistence`](packages/ecs-persistence)**: saving, loading and copying the entities of worlds, as
+  binary columns.
 - **[`ecs-todo-vanillajs`](packages/ecs-todo-vanillajs)**: a todo app whose world drives the DOM through systems,
   with vanilla custom elements.
 - **[`ecs-particles-webgpu`](packages/ecs-particles-webgpu)**: particles simulated by kernels, on the CPU and with

ecs/packages/ecs-gpu-views/src/README.md

@@ -11,7 +11,7 @@ GPU Views tab.
 
 - **Main** (`main.ts`) owns the page. It starts the world's worker and joins the world. It moves each `<canvas>` to the
   world's thread as the input of a run of `Surface.attach`, and `Surface.observe` sends each canvas's size in device
-  pixels whenever it changes. It spawns the views and the points, and adds `show`, an observer system writing the
+  pixels whenever it changes. It spawns the views and the points, and adds `show`, a readonly system writing the
   frame count into the overlay.
 - **The world's worker** (`world.ts`) creates the world, which ticks every frame, keeps it supplied with a device with
   `Device.keep`, and shares it on the port main sends.

ecs/packages/ecs-gpu-views/src/main.ts

@@ -17,7 +17,7 @@ let drawn = 0;
 /** Whether the world on the worker has shut down, after the page said it was leaving. */
 let left = false;
 // Added on this thread, it runs here after each of the world's frames.
-const show = System.create({ observer: true, resources: { changed: [frames] } }, ({ resources }) => {
+const show = System.create({ readonly: true, resources: { changed: [frames] } }, ({ resources }) => {
     drawn = resources[frames];
     overlay(`frame ${drawn} · drawn on the world's worker into two canvases: two views side by side, and one from above`);
 });

ecs/packages/ecs-gpu/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2025-2026 Adobe, Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

ecs/packages/ecs-gpu/package.json

@@ -5,16 +5,22 @@
   "license": "MIT",
   "type": "module",
   "sideEffects": true,
-  "private": true,
+  "private": false,
+  "independentVersion": true,
+  "publishConfig": {
+    "registry": "https://registry.npmjs.org/",
+    "access": "public"
+  },
   "files": [
     "dist",
     "src",
     "!src/**/*.test.ts",
     "!src/**/*.test-helper.ts",
-    "!src/**/*.test-worker.ts"
+    "!src/**/*.test-worker.ts",
+    "LICENSE"
   ],
   "scripts": {
-    "build": "tsc -p tsconfig.build.json && vite build",
+    "build": "cp ../../LICENSE . && tsc -p tsconfig.build.json && vite build",
     "typecheck": "tsc && tsc -p tsconfig.build.json",
     "test": "pnpm exec playwright install chromium && vitest --run"
   },

ecs/packages/ecs-guide/src/README.md

@@ -69,7 +69,7 @@ and so are the builds, a service that checks and compiles off the main thread an
   are rounded panels on the base background, a gutter apart, and the editor's colors are Spectrum's palette, whose
   tokens flip with the theme.
 
-Each feature's `model.ts` holds systems with input, one per thing that happens, and `dom.ts` the observer systems that
+Each feature's `model.ts` holds systems with input, one per thing that happens, and `dom.ts` the readonly systems that
 bind elements, with the ticking systems a feature needs, as one composite the app adds. `events.ts` turns DOM events,
 the builds' results and the frame's messages into runs. Typing stays smooth: each keystroke is one run and the
 bindings it changes, while checking, compiling and running happen in workers and the frame, after the code has been

ecs/packages/ecs-guide/src/app/compiled.page.test.ts

@@ -81,7 +81,7 @@ it("marks each of chapter 14's systems above its call with what it compiles to,
         await statusOf(page);
         const lenses = await lensesReading(page, chipLabels);
         expect(lenses.map(lens => lens.line.trim().slice(0, 30))).toEqual([
-            "const move = System.create({ c", "const drift = System.create({ ", "const slow = System.create({ k", "const read = System.create({ o", "const spawn = System.create(({",
+            "const move = System.create({ c", "const drift = System.create({ ", "const slow = System.create({ k", "const read = System.create({ r", "const spawn = System.create(({",
         ]);
         expect(lenses[0]?.label).toBe("move: JS compiled, WASM compiled, WGSL if declared kernel: \"gpu\". Show what it compiles to.");
         await (await chipOf(page, "spawn")).hover();

ecs/packages/ecs-guide/src/app/hover.page.test.ts

@@ -57,7 +57,7 @@ it.each(["dark", "light"] as const)("shows the types of what's hovered, System.c
         await away(page);
         await hoverWord(page, "await using world = World.create()", "create");
         const world = await hovered(page);
-        expect(world.signature).toMatch(/^\(property\) create: /);
+        expect(world.signature).toMatch(/^const create: /);
         expect(errors).toEqual([]);
     } finally {
         await page.close();

ecs/packages/ecs-guide/src/features/appearance/dom.ts

@@ -21,23 +21,23 @@ declare module "@adobe/ecs" {
 
 /** Colors the page light or dark, as the system prefers. */
 export const bindTheme = System.create({
-    observer: true,
+    readonly: true,
     resources: { is: [theme], changed: [dark] },
 }, ({ resources }) => {
     resources[theme].setAttribute("color", resources[dark] ? "dark" : "light");
 });
 
 /** Says whether this browser has WebGPU. */
 export const bindWebgpu = System.create({
-    observer: true,
+    readonly: true,
     resources: { is: [note], changed: [webgpu] },
 }, ({ resources }) => {
     resources[note].webgpu = resources[webgpu];
 });
 
 /** Shows the note in the chapter on GPU kernels only. */
 export const bindNote = System.create({
-    observer: true,
+    readonly: true,
     components: { with: [shown, chapterNumber], changed: [shown] },
     resources: { is: [note] },
 }, (row, { resources }) => {
@@ -49,7 +49,7 @@ export const bindNote = System.create({
  * without an example, there's nothing to resize.
  */
 export const bindColumns = System.create({
-    observer: true,
+    readonly: true,
     components: { with: [shown, sources] },
     resources: { is: [columnsElement] },
 }, (row, { resources }) => {

ecs/packages/ecs-guide/src/features/builds/dom.ts

@@ -36,7 +36,7 @@ declare module "@adobe/ecs" {
 
 /** Sends each revision of a chapter's files to be checked and compiled. */
 export const requestBuilds = System.create({
-    observer: true,
+    readonly: true,
     components: { with: [revision, sources], changed: [revision] },
     resources: { is: [builds] },
 }, (row, { resources }) => {
@@ -45,7 +45,7 @@ export const requestBuilds = System.create({
 
 /** Lists the shown chapter's problems, and marks the shown file's in the editor. */
 export const bindProblems = System.create({
-    observer: true,
+    readonly: true,
     components: { with: [shown, typeProblems, buildProblems, sources, fileShown], changed: [shown, typeProblems, buildProblems, fileShown] },
     resources: { is: [problemsElement, editor] },
 }, (row, { resources }) => {
@@ -57,7 +57,7 @@ export const bindProblems = System.create({
 
 /** Shows where the shown chapter's run is. */
 export const bindStatus = System.create({
-    observer: true,
+    readonly: true,
     components: { with: [shown, runState], changed: [shown, runState] },
     resources: { is: [statusElement] },
 }, (row, { resources }) => {
@@ -66,7 +66,7 @@ export const bindStatus = System.create({
 
 /** Shows what the shown chapter's run logged. */
 export const bindConsole = System.create({
-    observer: true,
+    readonly: true,
     components: { with: [shown, logged], changed: [shown, logged] },
     resources: { is: [consoleElement] },
 }, (row, { resources }) => {
@@ -78,7 +78,7 @@ export const bindConsole = System.create({
  * was last shown, and the Problems, each saying whether an error is among them.
  */
 export const bindTabs = System.create({
-    observer: true,
+    readonly: true,
     components: { with: [shown, tab, logged, consoleSeen, typeProblems, buildProblems], changed: [shown, tab, logged, consoleSeen, typeProblems, buildProblems] },
     resources: { is: [tabsElement] },
 }, (row, { resources }) => {
@@ -96,7 +96,7 @@ export const bindTabs = System.create({
 
 /** Lists what the shown chapter's systems compile to, and opens the one the reader chose. */
 export const bindCompiled = System.create({
-    observer: true,
+    readonly: true,
     components: { with: [shown, described, systemOpened], changed: [shown, described, systemOpened] },
     resources: { is: [compiledElement] },
 }, (row, { resources }) => {
@@ -107,7 +107,7 @@ export const bindCompiled = System.create({
 
 /** Lets the editor ask TypeScript what's at a place in the shown chapter's files. */
 export const bindQuickInfo = System.create({
-    observer: true,
+    readonly: true,
     components: { with: [shown], changed: [shown] },
     resources: { is: [editor, builds] },
 }, (row, { resources }) => {
@@ -118,7 +118,7 @@ export const bindQuickInfo = System.create({
 
 /** Marks the shown file's systems in the editor at their calls. */
 export const bindSystemMarks = System.create({
-    observer: true,
+    readonly: true,
     components: { with: [shown, described, sources, fileShown], changed: [shown, described, fileShown] },
     resources: { is: [editor] },
 }, (row, { resources }) => {
@@ -129,7 +129,7 @@ export const bindSystemMarks = System.create({
 
 /** Frames the shown chapter's latest run. */
 export const bindOutput = System.create({
-    observer: true,
+    readonly: true,
     components: { with: [shown, page], changed: [shown, page] },
     resources: { is: [outputElement] },
 }, (row, { resources }) => {

ecs/packages/ecs-guide/src/features/chapters/dom.ts

@@ -17,7 +17,7 @@ declare module "@adobe/ecs" {
 
 /** Lists the chapters in the navigation, in order, whenever a chapter is added. */
 export const bindChapters = System.create({
-    observer: true,
+    readonly: true,
     resources: { is: [nav] },
     lookup: { chapters: { index: inOrder, changed: true } },
 }, ({ resources, lookup }) => {
@@ -32,7 +32,7 @@ export const bindChapters = System.create({
 
 /** Shows the shown chapter: selected in the navigation, its prose, and its title in the page's. */
 export const bindShown = System.create({
-    observer: true,
+    readonly: true,
     components: { with: [shown, slug, chapterNumber, title, prose], changed: [shown] },
     resources: { is: [nav, proseElement] },
 }, (row, { resources }) => {

ecs/packages/ecs-guide/src/features/examples/dom.ts

@@ -24,7 +24,7 @@ declare module "@adobe/ecs" {
 
 /** Puts the shown chapter's shown file in the editor, and its files in the tabs; a chapter without examples hides them. */
 export const bindEditor = System.create({
-    observer: true,
+    readonly: true,
     components: { with: [shown, sources, fileShown], changed: [shown, sources, fileShown] },
     resources: { is: [editor, filesElement, exampleArea] },
 }, (row, { resources }) => {
@@ -37,7 +37,7 @@ export const bindEditor = System.create({
 
 /** Shows the lines asked for in the editor. */
 export const bindRevealed = System.create({
-    observer: true,
+    readonly: true,
     components: { with: [shown, revealed], changed: [shown, revealed] },
     resources: { is: [editor] },
 }, (row, { resources }) => {
@@ -46,7 +46,7 @@ export const bindRevealed = System.create({
 
 /** Lets the reset button reset only a chapter edited. */
 export const bindReset = System.create({
-    observer: true,
+    readonly: true,
     components: { with: [shown, sources, originals], changed: [shown, sources] },
     resources: { is: [resetElement] },
 }, (row, { resources }) => {

ecs/packages/ecs-guide/src/features/model.test.ts

@@ -19,7 +19,7 @@ type Read = {
 };
 const read: Read[] = [];
 const readChapters = System.create({
-    observer: true,
+    readonly: true,
     components: { with: [slug, chapterNumber, sources, revision, fileShown, revealed, runState, logged, page, typeProblems, buildProblems, tab, consoleSeen], optional: [shown] },
 }, row => {
     read.push({
@@ -190,7 +190,7 @@ it("frames a chapter shown again only once its new revision compiles, not its la
 /** What a chapter's systems compile to, and the system opened, as tests read them. */
 const compiledOf = async (world: World): Promise<unknown> => {
     let found: unknown = null;
-    await world.run(System.create({ observer: true, components: { with: [shown, described, systemOpened, tab, tabPicked] } }, row => {
+    await world.run(System.create({ readonly: true, components: { with: [shown, described, systemOpened, tab, tabPicked] } }, row => {
         found = { described: row[described], opened: row[systemOpened], tab: row[tab], picked: row[tabPicked] };
     }));
     return found;

ecs/packages/ecs-particles-webgpu/src/gpu/main.ts

@@ -61,7 +61,7 @@ const start = async (): Promise<void> => {
     await world.run(spawn, { count, width, height });
     /** For automated checks: a few drawn particles' positions, which an observer system reads back from the GPU. */
     const probed: (readonly number[])[] = [];
-    const probe = System.create({ observer: true, components: { with: [position, visible, enabled] } }, row => {
+    const probe = System.create({ readonly: true, components: { with: [position, visible, enabled] } }, row => {
         if (probed.length < 3) probed.push(row[position]);
     });
     Reflect.set(globalThis, "sampleProbe", async () => {

ecs/packages/ecs-particles-webgpu/src/particles.test.ts

@@ -23,7 +23,7 @@ describe("particles", () => {
         let positions: readonly (readonly number[])[] = [];
         for (const seconds of frames) positions = await frame(world, seconds);
         let spawned = 0;
-        await world.run(System.create({ observer: true }, ({ resources }) => { spawned = resources[count]; }));
+        await world.run(System.create({ readonly: true }, ({ resources }) => { spawned = resources[count]; }));
         expect(spawned).toBe(100);
         const expected = reference(frames);
         expect(positions).toHaveLength(expected.length);

ecs/packages/ecs-particles-webgpu/src/particles.ts

@@ -54,7 +54,7 @@ export const main = System.create({ systems: [spawn, gravity, integrate] });
 // Reads every position the frame left, in spawn order.
 const positions: Vec3[] = [];
 const read = System.create({
-    observer: true,
+    readonly: true,
     components: { with: [position] },
 }, row => {
     positions.push(row[position]);

ecs/packages/ecs-persistence/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2025-2026 Adobe, Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.