Eg JavaScript lets you trivially memoize asynchronous requests, by caching Promise objects instead of responses. In Elixir you'll end up with enormous case expressions like this one: https://github.com/melpon/memoize/blob/master/lib/memoize/ca...
A task is a process that calculates something and eventually returns a result, which you can get synchroneously with `Task.await/1`. There's also an equivalend for Promise.all, which is just `Enum.map(tasks, &Task.await/1)`.
You can store an Elixir task but you can only await it once. You can `.then` a JavaScript promise as often as you want which makes a promise an excellent primitive for caching things that take time (eg network requests) without triggering the same request twice.
Every time someone says "just make a process and a supervisor, put it elegantly in the supervisor tree, go think through the failure modes, ponder a bit about these 3 or 4 edge cases and potential race conditions, and you're done! hooray!" I get a bit grumpy.
Elixir is awesome, but there's a simplicity to a single-threaded execution model that takes away a lot of the things that make concurrency hard.
All I'm saying is that there are things that Elixir isn't the best at. Is that so weird? I feel like everybody responding to me has this strong emotional need to defend Elixir. Why? it's just a tool. Like any tool it has pros and cons.
https://github.com/fazibear/export and https://github.com/hansihe/rustler