refactor: simplify GameHost constructor to use GameModule

Update `GameHost` to accept a `GameModule` directly instead of
individual parameters. This simplifies the `createGameHost` factory
and improves type safety by preserving the module type.

Also apply `readonly` modifiers to `ContentModule` in the
slay-the-spire-like sample.

src/core/game-host.ts

@@ -12,6 +12,7 @@ export type GameHostStatus = "created" | "running" | "disposed";
 export class GameHost<
   TState extends Record<string, unknown>,
   TResult = unknown,
+  TModule extends GameModule<TState, TResult> = GameModule<TState, TResult>,
 > {
   readonly state: ReadonlySignal<TState>;
   readonly status: ReadonlySignal<GameHostStatus>;
@@ -29,16 +30,16 @@ export class GameHost<
   private _eventListeners: Map<"start" | "dispose", Set<() => void>>;
   private _isDisposed = false;
 
-  constructor(
+  constructor(public readonly gameModule: TModule) {
-    registry: CommandRegistry<IGameContext<TState>>,
+    const { createInitialState, registry, start } = gameModule;
-    createInitialState: () => TState,
-    start: (ctx: IGameContext<TState>) => Promise<TResult>,
-  ) {
     this._createInitialState = createInitialState;
     this._eventListeners = new Map();
 
     const initialState = createInitialState();
-    this._context = createGameContext(registry, initialState);
+    this._context = createGameContext(
+      registry ?? createGameCommandRegistry(),
+      initialState,
+    );
     this._start = start;
     this.state = this._context._state;
 
@@ -179,10 +180,7 @@ export type GameModule<
 export function createGameHost<
   TState extends Record<string, unknown>,
   TResult = unknown,
->(gameModule: GameModule<TState, TResult>): GameHost<TState, TResult> {
+  TModule extends GameModule<TState, TResult> = GameModule<TState, TResult>,
-  return new GameHost(
+>(gameModule: TModule): GameHost<TState, TResult> {
-    gameModule.registry || createGameCommandRegistry(),
+  return new GameHost(gameModule);
-    gameModule.createInitialState,
-    gameModule.start,
-  );
 }

src/index.ts

@@ -71,4 +71,6 @@ export { createRNG, Mulberry32RNG } from "./utils/rng";
 export type { MiddlewareChain } from "./utils/middleware";
 export { createMiddlewareChain } from "./utils/middleware";
 
+export * from "./utils/spawner";
+
 export * from "@preact/signals-core";

src/samples/slay-the-spire-like/data/types.ts

@@ -5,14 +5,14 @@ import type * as desert from "./desert";
 import { IRunContext } from "../system/combat";
 
 export type ContentModule = {
-  getCards: () => desert.Card[];
+  readonly getCards: () => readonly desert.Card[];
-  getEffects: () => desert.Effect[];
+  readonly getEffects: () => readonly desert.Effect[];
-  getEncounters: () => desert.Encounter[];
+  readonly getEncounters: () => readonly desert.Encounter[];
-  getEnemies: () => desert.Enemy[];
+  readonly getEnemies: () => readonly desert.Enemy[];
-  getIntents: () => desert.Intent[];
+  readonly getIntents: () => readonly desert.Intent[];
-  getItems: () => desert.Item[];
+  readonly getItems: () => readonly desert.Item[];
-  getStartingItems: () => desert.Item[];
+  readonly getStartingItems: () => readonly desert.Item[];
 
-  dialogues: YarnDialogues;
+  readonly dialogues: YarnDialogues;
-  addTriggers: (triggers: Triggers, run: IRunContext) => void;
+  readonly addTriggers: (triggers: Triggers, run: IRunContext) => void;
 };

src/samples/slay-the-spire-like/system/combat/index.ts

@@ -3,27 +3,3 @@ export * from "./factory";
 export * from "./prompts";
 export * from "./triggers";
 export * from "./types";
-
-import { GameHost } from "@/core/game-host";
-import { ContentModule } from "../types";
-import { createCommandRegistry } from "@/utils/command";
-import { createStart, createTriggers, Triggers } from "./triggers";
-import { CombatState, IRunContext } from "./types";
-
-export class CombatGameHost extends GameHost<CombatState> {
-  public readonly triggers: Triggers;
-  constructor(
-    private module: ContentModule,
-    private runContext: IRunContext,
-    private initialState: CombatState,
-  ) {
-    let triggers: Triggers;
-    super(
-      createCommandRegistry(),
-      () => initialState,
-      createStart((triggers = createTriggers(runContext)), runContext),
-    );
-    module.addTriggers(triggers, runContext);
-    this.triggers = triggers;
-  }
-}

src/utils/spawner.ts

@@ -0,0 +1,39 @@
+import { effect } from "@preact/signals-core";
+
+export type SpawnerFunction = (id: string) => () => void;
+
+export function createSpawner(spawner: SpawnerFunction) {
+  const entries = new Map<string, () => void>();
+
+  function update(set: Set<string>) {
+    for (const key of set) {
+      if (!entries.has(key)) {
+        entries.set(key, spawner(key));
+      }
+    }
+
+    for (const [key, entry] of entries) {
+      if (!set.has(key)) {
+        entry();
+        entries.delete(key);
+      }
+    }
+  }
+
+  return update;
+}
+
+export function spawnerEffect(
+  iterable: () => Iterable<string>,
+  spawner: SpawnerFunction,
+) {
+  const update = createSpawner(spawner);
+
+  return effect(() => {
+    const set = new Set<string>();
+    for (const each of iterable()) {
+      set.add(each);
+    }
+    update(set);
+  });
+}