Function resolveSlots

static/vuejs/vue.js:1947–1978

* Runtime helper for resolving raw children VNodes into a slot object.

(
  children,
  context
)

 * Runtime helper for resolving raw children VNodes into a slot object.
 */
function resolveSlots (
  children,
  context
) {
  var slots = {};
  if (!children) {
    return slots
  }
  var defaultSlot = [];
  var name, child;
  for (var i = 0, l = children.length; i < l; i++) {
    child = children[i];
    // named slots should only be respected if the vnode was rendered in the
    // same context.
    if ((child.context === context || child.functionalContext === context) &&
        child.data && (name = child.data.slot)) {
      var slot = (slots[name] || (slots[name] = []));
      if (child.tag === 'template') {
        slot.push.apply(slot, child.children);
      } else {
        slot.push(child);
      }
    } else {
      defaultSlot.push(child);
    }
  }
  // ignore whitespace
  if (!defaultSlot.every(isWhitespace)) {
    slots.default = defaultSlot;
  }
  return slots
}

function isWhitespace (node) {
  return node.isComment || node.text === ' '