add yield/await support

[sibelius]

nodejs/node#8382

[sibelius]

this could be helpful:

https://github.com/princejwesley/Mancy/blob/cd0bc938dce89a171b09f0862e22d143c8769eb1/src/common/ReplInput.js

[sibelius]

https://gist.github.com/princejwesley/a66d514d86ea174270210561c44b71ba

[paulserraino]

Nice, the links you've provided are great. 👍 I like the idea of adding support for yield/await. Perhaps there's a way to make babel-repl more extensible? We could provide an optional "hook" for pre-processing code before the eval method is called.

[sibelius]

I think we don't have much syntax to preprocess

• await syntax (wrap in a async function)
• yield syntax (wrap in a generator function - https://github.com/sidorares/repl-co)

we could read .babelrc of user and use it to transform code properly, right now you are not using any babel preset or plugin