save dialog

packages/web/src/utility/createReducer.ts

@@ -0,0 +1,11 @@
+import { writable } from 'svelte/store';
+
+export default function createReducer(reducer, initialState): any {
+  const state = writable(initialState);
+
+  function dispatch(action) {
+    state.update(x => reducer(x, action));
+  }
+
+  return [state, dispatch];
+}