Function mapRemainingChildren

lib/assets/react-source/development/react.js:17175–17193

(returnFiber, currentFirstChild)

	  }

	  function mapRemainingChildren(returnFiber, currentFirstChild) {
	    // Add the remaining children to a temporary map so that we can find them by
	    // keys quickly. Implicit (null) keys get added to this set with their index
	    // instead.
	    var existingChildren = new Map();
	    var existingChild = currentFirstChild;

	    while (existingChild !== null) {
	      if (existingChild.key !== null) {
	        existingChildren.set(existingChild.key, existingChild);
	      } else {
	        existingChildren.set(existingChild.index, existingChild);
	      }

	      existingChild = existingChild.sibling;
	    }

	    return existingChildren;
	  }

	  function useFiber(fiber, pendingProps) {
	    // We currently set sibling to null and index to 0 here because it is easy