Two Approaches to Optimizing JavaScript

This is a really nice exchange of posts on two different approaches to optimizing JavaScript:

Nick Fitzgerald writes about speeding up source maps with Rust and WebAssembly, Vyacheslav Egorov (mraleph) responds with a masterclass in using profiling and expertise to get similar speedups in pure JavaScript, and Nick caps off the exchange by porting some of mraleph's speedups back to Rust and talking about trade-offs.

Civil, fair-minded, technically interesting, and we're 300% faster than when we started.  All programming debates should happen like this.