The .d.ts syntax intentionally looks like ES Modules syntax. ES Modules was ratified by TC39 in 2015 as part of ES2015 (ES6), while it has been available via transpilers for a long time

default export (esModuleInterop:true) / export = 

讲一个 d.ts  export 的所有内容作为一个 namespace

 export as namespace xxx 和 namespace xxx