Why async fn in traits are hard

Re:Why async fn in traits are hard by noncoml on Sunday October 27, 2019 @04:12AM (#21368444)

Not in dynamic languages, ie JavaScript

[ Parent | on HN ]

Re:Why async fn in traits are hard by littlestymaar on Sunday October 27, 2019 @04:38AM (#21368521)

It is. It's not visible if you the types aren't written, but under the hood, that's the type of things like this.

[ Parent | on HN ]

Re:Why async fn in traits are hard by noncoml on Sunday October 27, 2019 @04:45AM (#21368539)

Ehm. No. JavaScript will return a Promise. It’s “type” is Object as pretty much anything else in JavaScript.

[ Parent | on HN ]

Re:Why async fn in traits are hard by endless1234 on Sunday October 27, 2019 @04:51AM (#21368557)

But isn't a Promise for all intents and purposes the same as a Future here?

[ Parent | on HN ]

Re:Why async fn in traits are hard by marcoms on Sunday October 27, 2019 @07:13AM (#21369035)

Yes, but I think they are emphasising that only a promise will be returned. Any further type information is not given

[ Parent | on HN ]

Re:Why async fn in traits are hard by wwright on Sunday October 27, 2019 @08:16AM (#21369246)

Check out structural typing. I would say it’s the type system JavaScript uses for non-primitive values. The “dynamic” appearance is just that JavaScript doesn’t center the type system in its UX.

[ Parent | on HN ]