Function listNodeFor

src/List.js:566–579

* Returns the leaf `VNode` holding `rawIndex`, or `undefined` when no node is * allocated for it (an all-`undefined` region). * * @param {List} list * @param {number} rawIndex * @returns {VNode | undefined}

(list, rawIndex)

 * @returns {VNode | undefined}
 */
function listNodeFor(list, rawIndex) {
  if (rawIndex >= getTailOffset(list._capacity)) {
    return list._tail;
  }
  if (rawIndex < 1 << (list._level + SHIFT)) {
    let node = list._root;
    let level = list._level;
    while (node && level > 0) {
      node = node.array[(rawIndex >>> level) & MASK];
      level -= SHIFT;
    }
    return node;
  }
}

/**
 * Validates requested bounds before int32 coercion in setListBounds().