blusher

https://github.com/momiji-rs/blusher

blusher routes Ruby's rouge lexing — and, for the common HTML path, its formatting — through the Rust `carmine` engine, which executes rule tables extracted from rouge's own lexers. For an unadorned Rouge::Formatters::HTML pipeline it fuses lex+format in Rust and returns one String, crossing the Ruby boundary once instead of per-token: ~1.7x faster on a mixed corpus (2.5x+ on large files), byte-identical, with transparent fallback to rouge for callback lexers and other formatters. Verified against rouge's full lexer spec suite (757/757). The engine's raw 4.6x is realized Rust-to-Rust.