object: cellifyObject

src/object.test.ts

@@ -1,7 +1,7 @@
 import { expect, test } from "vitest";
 
 import { _cellify, _uncellify } from "./cellify";
-import { mapObject, reduceObject } from "./object";
+import { cellifyObject, mapObject, reduceObject } from "./object";
 import { SheetProxy } from "./proxy";
 import { Sheet } from "./sheet";
 
@@ -66,3 +66,19 @@ test("reduceObject", async () => {
   await expect(v.get()).resolves.toBe(14);
   expect(sheet.stats).toEqual({ count: 8, size: 7 }); // +1 cell, update pointer
 });
+
+test("cellifyObject", async () => {
+  const sheet = new Sheet();
+  const proxy = new SheetProxy(sheet);
+  const obj = proxy.new({ a: 1, b: 2, c: 3 } as Record<string, number>);
+  const c = cellifyObject(proxy, obj);
+  await expect(_uncellify(c)).resolves.toEqual({ a: 1, b: 2, c: 3 });
+  expect(sheet.stats).toEqual({ count: 5, size: 5 }); // 1 obj + 3 ç + 1 map
+  expect(sheet.get(2).value).toBe(1);
+
+  obj.set({ a: 4, b: 2, d: 10 });
+  await expect(_uncellify(c)).resolves.toEqual({ a: 4, b: 2, d: 10 });
+  expect(sheet.stats).toEqual({ count: 6, size: 6 }); // +1 ç
+  expect(sheet.get(2).value).toBe(4); // cell has been updated
+  expect(sheet.get(5).value).toBe(10); // last created is 10
+});

src/object.ts

@@ -1,4 +1,4 @@
-import type { AnyCell, MapCell } from "./cell";
+import type { AnyCell, MapCell, ValueCell } from "./cell";
 import { collector } from "./gc";
 import type { SheetProxy } from "./proxy";
 
@@ -75,3 +75,28 @@ export const reduceObject = <
     nf
   );
 };
+
+export const cellifyObject = (
+  proxy: SheetProxy,
+  obj: AnyCell<Record<string, unknown>>,
+  name = "çObj"
+): MapCell<CellObject, true> => {
+  const set = <T>(c: ValueCell<T>, v: T): ValueCell<T> => {
+    c.set(v);
+    return c;
+  };
+  return proxy.map(
+    [obj],
+    (_obj, prev) => {
+      // @todo delete unused cells
+      return Object.fromEntries(
+        Object.entries(_obj).map(([k, v]) => [
+          k,
+          prev?.[k] ? set(prev[k], v) : proxy.new(v)
+        ])
+      );
+    },
+    name,
+    true
+  );
+};