GraphQL 字段作为函数

我在学习GraphQL在编写时，我对特定问题的不同实现感到有点困惑fields of a GraphQLObjectType.
这两种实现有什么区别？

1.

var schema = new GraphQLSchema({
  query: new GraphQLObjectType({
    name: 'RootQueryType',
    fields: {  // as object
      echo: {
        type: GraphQLString,
        args: {
          email: { type: EmailType }
        },
        resolve: (root, {email}) => {
          return email;
        }
      }
    }
  })
});

var ComplicatedArgs = new GraphQLObjectType({
  name: 'ComplicatedArgs',
  fields: () => ({ // as function
    complexArgField: {
      type: GraphQLString,
      args: {
        complexArg: { type: ComplexInput }
      },
    }
  }),
});

当你需要进行循环引用时。

在这里寻找我的类似答案

使用循环引用动态创建 graphql 模式 https://stackoverflow.com/questions/39256942/dynamically-creating-graphql-schema-with-circular-references/39290345#39290345