Vivarium · Layer 1 · Rust (wasm32-wasip1)

Reproducing rust-lang/regex#779

The Rust regex crate violates a basic regex algebra: (re)+ should equal (re)(re)*, but with (?m)(^|a)+ against the haystack "a\naaa\n" the two equivalent forms produce different match-iteration outputs. RE2 and Go's regexp have the same divergence; PCRE2 gets it right, so this is an algebraic regex-engine bug rather than a regex-language ambiguity.