Explanation

Understanding-oriented discussion of how and why abnf works the way it does. These pages are for background reading, not step-by-step instructions.

• Architecture: parser combinators — parser combinators and the self-bootstrapping meta-grammar.

• The two backends — the pure-Python and Rust implementations behind one API.

• Alternation: longest match vs. first match — longest match vs. first match, and why it’s a choice.

• Backtracking and caching — how exponential blow-up is kept in check.

• Rust backend performance — where the Rust backend wins big and where the gap narrows.