whynot.js Formal Language Matching Framework

whynot.js is a generic, VM-based framework for matching formal languages, drawing inspiration from systems like Russ Cox's regular expression engine. It operates by considering all possible branches of a program in parallel, enabling efficient implementation of various language matching tasks, including regular expressions and XML schemas. A key differentiator is its ability to record program progress through input and grammar, providing detailed feedback on *why* an input might not match a given grammar. The current stable version is 5.0.0, with releases focusing on performance, memory optimization, and module compatibility (ESM/CJS). While there isn't a strict release cadence, updates address bug fixes, dependency bumps, and significant architectural improvements.