added basic scheduler and tree walker

examples/client-renderer/src/cr.ts

@@ -0,0 +1,49 @@
+interface FiberNode {
+  child?: FiberNode;
+  sibling?: FiberNode;
+  parent?: FiberNode;
+}
+
+let unitOfWork: FiberNode | null = null;
+
+function performUnitOfWork(fiber: FiberNode) {
+  console.log("performUnitOfWork", fiber);
+
+  if (fiber.child) {
+    return fiber.child;
+  }
+
+  let nextFiber: FiberNode | undefined = fiber;
+  while (nextFiber) {
+    if (nextFiber.sibling) {
+      return nextFiber.sibling;
+    }
+    nextFiber = nextFiber.parent;
+  }
+
+  return null;
+}
+
+function workLoop(deadline: IdleDeadline) {
+  while (unitOfWork && deadline.timeRemaining() > 0) {
+    unitOfWork = performUnitOfWork(unitOfWork);
+  }
+
+  if (unitOfWork) {
+    requestIdleCallback(workLoop);
+  } else {
+    // Commit all the changes that have accumulated.
+  }
+}
+
+function linkParents(fiber: FiberNode, parent?: FiberNode) {
+  fiber.parent = parent;
+  if (fiber.child) {
+    linkParents(fiber.child, fiber);
+  }
+  if (fiber.sibling) {
+    linkParents(fiber.sibling, fiber);
+  }
+}
+
+requestIdleCallback(workLoop);

examples/client-renderer/tsconfig.json

@@ -1,7 +1,7 @@
 {
   "compilerOptions": {
     // Environment setup & latest features
-    "lib": ["ESNext"],
+    "lib": ["ESNext", "DOM"],
     "target": "ESNext",
     "module": "Preserve",
     "moduleDetection": "force",