This program started out life as a fairly simple Go program that just runs everything in a single thread. I'm rewriting it in Rust for learning, but also because I think Rayon might let me make this problem parallelizable!
Here's an initial benchmark on a /usr/share/dict/words of 235,886 lines:
$ hyperfine './result/bin/similar-sort benchmark < /usr/share/dict/words'
Benchmark #1: ./result/bin/similar-sort benchmark < /usr/share/dict/words
Time (mean ± σ): 307.4 ms ± 6.0 ms [User: 273.5 ms, System: 75.5 ms]
Range (min … max): 298.3 ms … 317.2 ms 10 runs
Let's see if we can get any faster than that!