Function expandNodes

src/Map.js:812–820

(ownerID, nodes, bitmap, including, node)

}

function expandNodes(ownerID, nodes, bitmap, including, node) {
  let count = 0;
  const expandedNodes = new Array(SIZE);
  for (let ii = 0; bitmap !== 0; ii++, bitmap >>>= 1) {
    expandedNodes[ii] = bitmap & 1 ? nodes[count++] : undefined;
  }
  expandedNodes[including] = node;
  return new HashArrayMapNode(ownerID, count + 1, expandedNodes);
}

function popCount(x) {
  x -= (x >> 1) & 0x55555555;