onpair in experimental folder

[joseph-isaacs]

add the OnPair encoding in an experimental crate

[codspeed-hq]

Merging this PR will improve performance by 10.9%

⚠️ Unknown Walltime execution environment detected

Using the Walltime instrument on standard Hosted Runners will lead to inconsistent data.

For the most accurate results, we recommend using CodSpeed Macro Runners: bare-metal machines fine-tuned for performance measurement consistency.

⚠️ Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

⚡ 8 improved benchmarks
❌ 5 regressed benchmarks
✅ 1208 untouched benchmarks

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	Simulation	chunked_varbinview_opt_canonical_into[(1000, 10)]	187.8 µs	225.1 µs	-16.57%
⚡	Simulation	chunked_varbinview_canonical_into[(100, 100)]	308 µs	273.2 µs	+12.72%
⚡	Simulation	new_bp_prim_test_between[i16, 32768]	131.9 µs	119.8 µs	+10.15%
⚡	Simulation	new_alp_prim_test_between[f32, 16384]	118 µs	103.5 µs	+13.97%
⚡	Simulation	new_alp_prim_test_between[f32, 32768]	181.7 µs	152.9 µs	+18.86%
⚡	Simulation	decompress_rd[f32, (100000, 0.1)]	585.2 µs	412 µs	+42.03%
❌	Simulation	decompress_rd[f64, (10000, 0.1)]	123.5 µs	141.1 µs	-12.42%
⚡	Simulation	decompress_rd[f32, (100000, 0.01)]	585.2 µs	412 µs	+42.03%
❌	Simulation	decompress_rd[f64, (100000, 0.0)]	844.8 µs	980.4 µs	-13.84%
❌	Simulation	decompress_rd[f64, (10000, 0.01)]	123.1 µs	140.7 µs	-12.49%
⚡	Simulation	decompress_rd[f64, (100000, 0.1)]	1,022.8 µs	667.7 µs	+53.2%
❌	Simulation	decompress_rd[f64, (10000, 0.0)]	123.2 µs	140.7 µs	-12.47%
⚡	Simulation	decompress_rd[f64, (100000, 0.01)]	1,022.8 µs	667.6 µs	+53.2%

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

---

_{Comparing onpair-experimental (d323dcd) with develop (280f429)}