createFacory是对createElement的封装 ~~~ export function createFactory(type) { const factory = createElement.bind(null, type); // Expose the type on the factory and the prototype so that it can be // easily accessed on elements. E.g. `<Foo />.type === Foo`. // This should not be named `constructor` since this may not be the function // that created the element, and it may not even be a constructor. // Legacy hook: remove it factory.type = type; return factory; } ~~~