Husain, a senior developer at TC39 participant Netflix, also expressed reservations, saying that "if you make mistakes in your type system, you've hobbled the web." The committee is being very cautious because of the complications involved, Husain pointed out.
They are considering multithreading as well, with a proposal afoot for a shared array buffer with low-level primitives to exist between multiple threads, Penner said. There's also a proposal to do parallelism with web workers, for web content to run scripts in background threads, but there are complications with this. Husain noted that while parallelism would increase performance by leveraging multicore processors, it's "a very complicated problem," like a type system.
Long-planned async capabilities are on the drawing board, too. Husain offered an estimated timeframe of 2018, but he wasn't certain when it might arrive. "You can just say, 'An asynchronous workflow, do this, do that, do this.' It's asynchronous, but you don't have to register a callback," he said. The code looks like synchronous code but actually runs asynchronously.