class Regexp::Lexer
def descend(type, token)
def descend(type, token) if type == :group or type == :assertion @nesting += 1 if OPENING_TOKENS.include?(token) end if type == :set or type == :subset @set_nesting += 1 if token == :open end if type == :conditional @conditional_nesting += 1 if token == :open end end