A comment upthread did the math:

> The author is able to achieve a speed-up of ~4x which is close to the 5.89x achieved by the Rust implementation.

The math is not that obvious because Rust implementation does not match 1-1 what baseline JS version was doing (e.g. it sorts only generatedMappings and not originalMappings).

I will do measurements later to compare and update the post.

Sounds good!

I enjoyed the article :)

With the caveat that it's apples-to-oranges (algorithmic changes to the JavaScript version (~4x) are not in the Rust version (~5.9x)).