I’m mostly ok with this. I do prefer lists, but I’ve been working on performance-sensitive code for the last few months and the more we switch to arrays the better it performs. For functional recursion lists are essential, and we still do that where performance doesn’t matter, but I’ve found that for most list-based algorithms an equivalent (but less pure) array-based algorithm is usually much faster in JS. What I lose in write speed I more than make back in read speed (likely due to memory locality and CPU caches).
Pattern matching works on [||]
arrays today, with the same caveats and warnings. It’s an underlying OCaml feature. Array patterns are fixed length so it’s not widely useful, but I have found it to be handy at times.