Show HN: Frpjs – Functional reactive programming library for JavaScript

Incremental DOM updates cause layout thrashing which, when comlared to making a few additional passes over a set, is a couple of orders of magnitude more expensive.

The point is, walk/filter the data completely prior to updating the view.

Immutable sets may also 'seem' inefficient but compare-by-reference works a of a lot faster than change propogation with compare-by-deeply-nested-values.

In CompSci terms, multiple passes are still O(n) and the data sets aren't large enough for micro-optimizations to matter. Compared to O(holy shit) of triggering many cascading DOM updates, it's a huge improvement.

'Seems' isn't a good enough metric to justify optimization.

I don't think either Redux or Flux are related to FRP at all.

That said, your point still stands. RxJS has very smart people behind it and at least one big company that uses it heavily (Netflix). Its newest releases include modularized loading for smaller bundle builds.

RxJS uses the observer pattern and is not really FRP in the Haskell sense of things.

This is implemented in pure vanilla JavaScript.