bcndanos / asynchronous Goto Github PK

It makes sense to have the promise chain begin in a new thread from Promise::new(), however beyond that the continuations themselves shouldn't be in separate threads of their own. They should all run on the originating thread where the Promise was created.

Apart from the thread locality of the continuations, the idea of creating a separate thread for each continuation is expensive. These aren't green threads, and so I'm afraid this Promise implementation will not scale well when put to the test.

Right now the promise closure must return only a Result<T, E> type, which makes it clunky to chain promise handlers together. A coherent promise implementation allows one to return a value or another promise, and when a continuation is done on the outer promise, it is continuing on the inner promise that was returned.

I suggest creating an enum type for the return type of all the methods, that can be either another Promise<T, E> type or be a Result<T, E> type. I have no idea if Rust's type system will get in the way here, or type inference will fail miserably...but this is the first thing that comes to my mind when thinking about solving the problem.

Hi,

Looks like a cool library, only have one small feature request: a non blocking try_sync that returns a value if there is one and None otherwise.