feat(commands): add app state dispatcher foundation

editor/store.ts

@@ -0,0 +1,39 @@
+import type { CommandDispatcher } from "@commands/dispatcher";
+import { createCommandDispatcher } from "@commands/dispatcher";
+import type { CommandRegistry } from "@commands/registry";
+import type { AppState } from "./state";
+
+export type StateListener = (state: AppState) => void;
+
+export type AppStore = {
+  getState(): AppState;
+  subscribe(listener: StateListener): () => void;
+  dispatch: CommandDispatcher["dispatch"];
+};
+
+export function createAppStore(initialState: AppState, registry: CommandRegistry): AppStore {
+  let state = initialState;
+  const listeners = new Set<StateListener>();
+
+  const emit = () => {
+    for (const listener of listeners) listener(state);
+  };
+
+  const dispatcher = createCommandDispatcher({
+    registry,
+    getState: () => state,
+    setState: (nextState) => {
+      state = nextState;
+      emit();
+    },
+  });
+
+  return {
+    getState: () => state,
+    subscribe(listener) {
+      listeners.add(listener);
+      return () => listeners.delete(listener);
+    },
+    dispatch: dispatcher.dispatch,
+  };
+}