While I’d love to have people try this, now that we know that native code will not be usable in 0.19, I recommend that you don’t spend time doing so. But one thing that will still be very valuable is feedback on your concrete use case. In your second case for example, you mention slicing and joining. Great, I’d suggest that once you’re advanced enough in your project, you create a post explaining the API you’ve come up with, and the pain points you had implementing it with current available array API and ports. This will be very valuable input for core elm members. And possibly, some solutions might appear in pure elm for part of these issues.
I used to do that also for one of my image manipulation use cases. Eventually I had issues with elm Array type that forced me to switch to Robin’s array exploration (HAMT array). At this moment, JS interop by ports became a burden because HAMT array was not a type directly supported. The good news is that Robin’s work is now merged in elm 0.19 so it will get better in 0.19.
Indeed 