> I'm not aware of sub-state-machines as a standard concept. That just means you've never looked into it nor have much experience with state machines. Sub-sta

> I'm not aware of sub-state-machines as a standard concept. That just means you've never looked into it nor have much experience with state machines. Sub-state machines are even supported as a basic features in some popular GUI frameworks such as Qt. Qt in turn uses W3C's SCXML format[1] to represent state machines, which not only supports substates but also parallel states. [1] https://www.w3.org/TR/scxml/ https://www.w3.org/TR/scxml/ If anything, anyone with any experience writing any parser is already aware that the lexer represents a sub-state machine, and this is close to CS101.