Struct ContentModelNfa 

pub struct ContentModelNfa { /* private fields */ }

Incremental content-model matcher stored in _xmlElement.cont_model.

The candidate’s regex engine matches character-by-character, which does not model upstream’s whole-name content-model tokens, so the content model is compiled into a dedicated small NFA over full element names. Upstream builds the same automaton (xmlValidBuildAContentModel) and then converts it with xmlRegFromAutomata; the observable push/pop contract is identical (per-push “Misplaced” errors, completion checks on pop).