Dynamic import

関数呼び出しっぽくimportを使う

例：https://github.com/tc39/proposal-dynamic-import#example

モチベーション

This could be because of factors only known at runtime (such as the user's language), for performance reasons (not loading code until it is likely to be used), or for robustness reasons (surviving failure to load a non-critical module). Such dynamic code-loading has a long history, especially on the web, but also in Node.js (to delay startup costs). The existing import syntax does not support such use cases.

Code splittingをするときにできないと困る