Action context

Actions run in the lexer context. Common methods include:

API	Use
text / text_bytesize	Matched text and its byte length
emit(type, value = text)	Return a token
skip	Consume input without emitting a token
echo	Write the matched text to the configured output
lineno, line, byte_pos	Current position information
beginning_of_line?	Check the start-of-line condition
state, push, pop, begin_state	Manage lexer states
less(n) / more	Adjust or extend the current match
error!(message)	Raise a lexer error with location context

Prefer small, deterministic actions. If an action needs parser state or external services, keep that dependency in an adapter around the lexer.