Public API and stability
Public and stable
Section titled “Public and stable”Flexr::Lexer, the lexer DSL, runtime token/location structures, the documented CLI, and Flexr::RakeTask are the supported entry points for normal use.
Experimental
Section titled “Experimental”The firstmatch backend and any option explicitly marked experimental may change behavior or API shape between releases. Opt in deliberately and test the resulting token stream.
Internal
Section titled “Internal”Flexr::IR, Flexr::Automaton, Flexr::Codegen, parser internals, and generated implementation helpers are internal. Compatibility is not guaranteed for these namespaces.
Version-specific guarantees live in the compatibility reference and the release commits.