anchor.diff:    typical ES2015 features or support testing right out-of-the-box.
   
     “快速起步”本身不需要这些类型定义，但是文档中的很多例子都需要。
  -  如果没有写针对典型ES2015特性的代码或者写支持外部测试的代码，那我们多半儿会失望 —— 类型定义就没用了。
  +  如果不能直接编写典型ES2015特性的代码或者写支持外部测试的代码，大部分读者会很失望（所以快速起步中有这些类型定义）。
   
     We can also run the *typings* tool ourselves.
     The following command (re)installs the typings files, as is sometimes necessary when the `postInstall` hook fails to do so.
  
positive.code:   The following command installs or updates the typings file for the Jasmine test library from the *DefinitelyTyped* repository
    and updates the `typings.config` so we that we get it automatically the next time we install typings.
  
    下列命令会从*DefinitelyTyped*仓库中为Jasmine测试库安装类型定义文件，并更新`typings.config`文件，以便当我们下次安装类型定义文件时会自动获取它。
  code-example(format="").
    npm run typings -- install dt~jasmine --save --global
  .l-sub-section
    :marked
      The [&ndash;&ndash; option](https://docs.npmjs.com/cli/run-script) is important;
      it tells npm to pass all arguments to the right of `--` to the *typings* command.
  
      这个[&ndash;&ndash;选项](https://docs.npmjs.com/cli/run-script)是很重要的，
      它告诉npm要把`--`右侧的所有参数都传给*typings*命令。
  
      Learn about the features of the *typings* tool at its [site on github](https://github.com/typings/typings/blob/master/README.md).
  
negative.code:   &mdash; *d.ts files* &mdash; to tell the compiler about the libraries we load.
  
    我们可以使用[TypeScript类型定义文件](http://www.typescriptlang.org/Handbook#writing-dts-files)
    —— *.d.ts文件* ——来告诉编译器要加载的库的类型定义。
  
    TypeScript-aware editors leverage these same definition files to display type information about library features.
  
  