baru-re WASM playground
A standalone C regex engine (ECMAScript-flavored: named groups, lookaround,
\p{…} Unicode properties, /u//v mode)
running as compiled WebAssembly, in your browser — no server involved.
Source on GitHub
This page loads the exact src/re_lexer.c / re_parser.c /
re_compiler.c / re_vm.c / regex_wasm.c
compiled by make wasm in this repo — nothing here is reimplemented in JS.
The compiled Program struct and its backtracking VM run entirely inside
the WASM sandbox; this page only marshals UTF-16 buffers in and capture offsets out.
Known limitations: this engine has a few confirmed correctness
issues — see
docs/IMPROVEMENTS.md
for the full list with reproductions. The crash this page used to warn about here
(deeply nested lookaround exhausting the stack) is fixed; the remaining known issues
are wrong-answer bugs, not confirmed crashes. This page still catches a WASM-level
crash and reloads the engine automatically if it ever encounters one, as
defense-in-depth rather than a known, reproducible path.