rewrite in rust

[anonrig]

Benchmark results

Measured on the same 11-URL corpus as the README (808 bytes total).

Implementation	parse	can_parse
C++ backend (README baseline)	2.016 µs — 382 MiB/s	1.212 µs — 636 MiB/s
Pure Rust (stable, no feature flags)	1.503 µs — 513 MiB/s	0.454 µs — 1 697 MiB/s
Pure Rust + nightly-simd (std::simd, nightly only)	1.457 µs — 529 MiB/s	0.511 µs — 1 508 MiB/s
servo url crate	3.562 µs — 216 MiB/s	—

• parse is 25% faster than the C++ backend (stable), 28% faster with nightly SIMD
• can_parse is 2.7× faster than the C++ backend with zero heap allocations for any input
• Both beat the servo url crate: parse by 2.4×, can_parse by a wide margin

[Copilot]

Pull request overview

This PR rewrites the URL parsing/validation stack in pure Rust, removing the C++/FFI backend and adding a fast-path can_parse validator plus new internal modules (Unicode/IDNA, helpers, serializers, scheme hashing, optional portable SIMD).

Changes:

• Replace C++ FFI URLSearchParams + IDNA bindings with pure-Rust implementations.
• Add a zero-allocation URL validator used by Url::can_parse (plus a fast-path in the parser).
• Introduce new internal modules for scheme classification, Unicode utilities, IDNA, serializers, helpers, and optional std::simd acceleration.

Reviewed changes

Copilot reviewed 19 out of 23 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
src/validator.rs	New zero-allocation can_parse validator (scheme/authority/host/IDNA checks).
src/url_search_params.rs	Pure-Rust URLSearchParams implementation (parse/serialize/sort/iterators).
src/unicode.rs	Unicode helpers (percent-encode/decode, classification, domain ASCII conversion).
src/serializers.rs	IPv4/IPv6 serialization helpers.
src/scheme.rs	Perfect-hash special-scheme classification.
src/portable_simd_impl.rs	Nightly-only std::simd accelerated scanning paths.
src/parser.rs	Parser fast-paths and integration with the new validator.
src/idna_impl.rs	Pure-Rust IDNA (UTS #46) + punycode implementation.
src/idna.rs	Public IDNA wrapper updated to use pure-Rust implementation.
src/helpers.rs	New helper utilities used by parser.
src/checkers.rs	New validation/check helpers (IPv4, path signature, etc.).
src/character_sets.rs	Percent-encode character sets and lookup tables.
src/ffi.rs	Removed FFI bindings to Ada C++ backend.
build.rs	Removed C++ build integration.
Cargo.toml	Remove build-deps; add nightly-simd feature.
Cargo.lock	Updated dependency graph after removing build dependencies.
rust-toolchain.toml	Toolchain bump.
justfile	Exclude SIMD features from feature-powerset commands.
.github/workflows/ci.yml	Exclude nightly-simd from feature-powerset CI runs.
bench/parse.rs	Benchmark import cleanup.

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[Boshen]

Faster than C++ how?

[anonrig]

Faster than C++ how?

@Boshen I've added more benchmarks. We will see if this holds true!

[codspeed-hq]

Merging this PR will degrade performance by 23.91%

⚡ 7 improved benchmarks
❌ 1 regressed benchmark
✅ 8 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
⚡	Simulation	ada_url	5.6 ms	3.8 ms	+47.82%
⚡	Simulation	ada_url	16.7 µs	13.2 µs	+26.64%
❌	Simulation	ada_url	1.3 ms	1.7 ms	-23.91%
⚡	Simulation	ada_url	11.9 µs	3.3 µs	×3.6
⚡	Simulation	ada_url_parse	196 ms	165.3 ms	+18.6%
⚡	Simulation	ada_url	204.8 µs	142.1 µs	+44.16%
⚡	Simulation	ada_url	18.1 µs	6.8 µs	×2.7
⚡	Simulation	ada_url	1,336.4 µs	884.2 µs	+51.14%

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_{Comparing yagiz/rewrite-rust (d562027) with main (4df14c4)}

[anonrig]

@lemire it seems we can go a lot faster in C++ :-))

[anonrig]

Faster than C++ how?

Not anymore @Boshen ada-url/ada#1106

[Boshen]

Faster than C++ how?

Not anymore @Boshen ada-url/ada#1106

very good