anchor.diff:        :marked
           Note that you can often achieve this same goal using [Angular modules](#angular-module) instead.
   
  +        同じ目的のために、[Angularモジュール](#angular-module)を使うことがあるので覚えておきましょう。
  +
   :marked
     ## Binding
     ## バインディング
  
positive.code:       export class HeroService {}
      :marked
        Without a barrel, a consumer would need three import statements:
      code-example.
        import { HeroComponent } from '../heroes/hero.component.ts';
        import { Hero }          from '../heroes/hero.model.ts';
        import { HeroService }   from '../heroes/hero.service.ts';
      :marked
        We can add a barrel to the `heroes` folder (called `index` by convention) that exports all of these items:
      code-example.
        export * from './hero.model.ts';   // re-export all of its exports
        export * from './hero.service.ts'; // re-export all of its exports
        export { HeroComponent } from './hero.component.ts'; // re-export the named thing
      :marked
        Now a consumer can import what it needs from the barrel.
      code-example.
        import { Hero, HeroService } from '../heroes'; // index is implied
      :marked
        The Angular [scoped packages](#scoped-package) each have a barrel named `index`.
  
        That's why we can write this:
  
      +makeExcerpt('quickstart/ts/app/app.component.ts', 'import', '')
  
  
negative.code: +ifDocsFor('ts|js')
    :marked
      ## Barrel
  
      ## バレル (Barrel)
    .l-sub-section
      :marked
        A barrel is a way to *rollup exports* from several ES2015 modules into a single convenience ES2015 module.
        The barrel itself is an ES2015 module file that re-exports *selected* exports of other ES2015 modules.
  
        バレルは、複数のES2015モジュールをひとつのES2015モジュールに*まとめてエクスポートする*方法です。
        バレル自身は、ES2015モジュールのファイルであり、*選択された*他のES2015モジュールのエクスポートを再エクスポートします。
  
        Imagine three ES2015 modules in a `heroes` folder:
  
        `heroes`フォルダにある、3つのES2015モジュールをイメージしてください：
      code-example.
        // heroes/hero.component.ts
        export class HeroComponent {}
  