I'm a huge fan of persistent data structures such as those implemented by immutable.js. The "normal" way that I would update an immutable.js List is just: numb

I'm a huge fan of persistent data structures such as those implemented by immutable.js. The "normal" way that I would update an immutable.js List is just: numbers = numbers.push(numbers.length + 1); Maybe it's just a coincidence, but Svelte seems awfully congruent with the pure FP way of doing things.