Author here. Yeah, in fairness this post doesn't go into benchmarking (that would be interesting as a follow up). Though I would argue even for libraries that a

Author here. Yeah, in fairness this post doesn't go into benchmarking (that would be interesting as a follow up). Though I would argue even for libraries that aren't numerically intensive (like the one I used in this blog post), I'd imagine the speeds are probably comparable to the JavaScript runtime if you don't have to boundary cross very often. In this case, the main thing that was "fast" was that I didn't have to rewrite a nontrivial string formatting library in a new language (I literally couldn't find any other JavaScript libraries that had this kind of error-formatting functionality, so that would have been my only other option). :-)