perf: move to filter map from map and filter
Instead of doing two passes of all candidates using map then a filter,
this uses filter_map so we are only doing one pass for the candidates.
This alone is quite a significant improvement of ~7%
Output of ./scripts/bench 0.x
Benchmark 1: 0.x
Time (mean ± σ): 2.373 s ± 0.138 s [User: 10.617 s, System: 1.697 s] Range (min … max): 2.124 s … 2.577 s 10 runs
Benchmark 2: HEAD
Time (mean ± σ): 2.206 s ± 0.133 s [User: 10.061 s, System: 1.811 s] Range (min … max): 1.940 s … 2.433 s 10 runs
Summary
HEAD ran 1.08 ± 0.09 times faster than 0.x