The line is blurrier in my eyes. The library combines regular grammars that need an interpreter (the `match` method, which is bundled with the regexp object),

The line is blurrier in my eyes. The library combines regular grammars that need an interpreter (the `match` method, which is bundled with the regexp object), whereas parser combinators work on code written in the same language (that is ultimately interpreted by the CPU). Edit: the parser in this case is a `(Regexp.prototype.match, regex.source)` tuple, whereas in the case of a praser combinator lib in a language that compiles to machine code, it would be `(call instruction, instructions list)`.