ieviev / resharp

What is resharp?

Resharp is a Rust regex engine that compiles patterns into deterministic automata for guaranteed linear-time matching on byte slices. It solves the problem of standard engines degrading on complex patterns like large alternations, lookarounds, or boolean combos by adding first-class intersection (`&`), complement (`~`), and universal wildcard (`_`). Drop it in with `cargo add resharp` for `find_all` and `is_match` on `&[u8]`, returning leftmost-longest matches without backtracking.

Why is it gaining traction?

It crushes the `regex` crate on benchmarks for dense matches, case-insensitive searches, and lookarounds—449 MiB/s vs 58 MiB/s on 2600-word dictionaries, even on low-power ARM. Devs grab it as a github re engine alternative when `regex` hits NFA fallback or `fancy-regex` backtracks slowly, plus syntax extensions enable patterns impossible elsewhere, like "contains 'a' but not 'b'". Not a ReSharper JetBrains fork or C++ tool—this is pure Rust re framework for high-perf text processing.

Who should use this?

Rust backend devs parsing logs with lookarounds or validating inputs via intersections, like security scanners checking multiple conditions without slow hacks. Data engineers matching huge alt lists in pipelines, or game devs (re ue4ss style) needing fast anchored finds on game logs. Skip if you need captures or lazy quantifiers—stick to `regex` for basics.

Verdict

Grab it for complex patterns where std regex chokes; benchmarks and syntax docs make it easy to test via github re open pull request or re run ci. At 44 stars and 1.0% credibility, it's early-stage but mature enough for prod trials—excellent paper/blog backing, just watch capacity limits on massive DFAs.

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