Tried to put it into my svelte project. Build failed. Went onto github to report it. A reproduction url is required ... so not submitting a bug ... and looking for something else to use ...
This is how I felt when trying to learn Elm: the program had to be correct, exactly correct, or it wouldn't work. You had to make every piece, every function, fit precisely, to define it's shape, it's exact inputs and outputs and effects ... in the end I found it very restrictive. I like the idea of loose-ness by default and adding contraints gradually (like javascript -> typescript).
Someone on YouTube mentioned that LK99 is ceramic ie not metal which nullifies many of its potential uses even if it does turn out to be superconducting
Reactivity, yes - works the same as MobX's autorun. But not derived values. You can ensure something gets updated by wrapping it in $:
```
$: value = $x + 2
```
but you can do that somewhere else as well
```
$: {
let y = 20
$value += y
}
```
Makes it insanely hard to track where changes come from. You can't say "this value is _only_ updated by these changes".
You can do this with derived stores, though. But each store must be it's own, separate value - with MobX's observable you have a central object representing your entire state, each of which is made automatically reactive, and putting in a derived store is just prepending with -get-. It's much cleaner.