It is interesting to note how it compares to "choose" (also in Rust) in the benchmarks. single character hck 1.494 ± 0.026s hck (no-mmap) 1.

It is interesting to note how it compares to "choose" (also in Rust) in the benchmarks. single character hck 1.494 ± 0.026s hck (no-mmap) 1.735 ± 0.004s choose 4.597 ± 0.016s multi character hck 2.127 ± 0.004s hck (no-mmap) 2.467 ± 0.012s choose 3.266 ± 0.011s The single pass optimization trick[1] seems to be helping a lot in single character case. Of course, doing away with a pass is suppossed to give 2x, and I am wondering whether the regex constraint lead to this "side-effect". [1] fast mode - https://github.com/sstadick/hck/blob/master/src/lib/core.rs#L194 https://github.com/sstadick/hck/blob/master/src/lib/core.rs#... https://github.com/sstadick/hck/blob/master/src/lib/core.rs#L324-L331 https://github.com/sstadick/hck/blob/master/src/lib/core.rs#...