context si
	lex
		literal '!', 'a', ';\n'

		token id /'a'|'b'/
		{
			input.push( make_token( trans_id_to input.pull(match_length) ) )
		}
		
		token super_id //
		token foo //

		ignore ws / [ \n\t]+ /
	end

	trans_id_to: int

	def e1 
		[]
		{
			print( 'old_id = ' trans_id_to '\n' )
			trans_id_to = typeid<foo>
			print( 'new_id = ' trans_id_to '\n' )
		}

	def item1 
		msg: str

		[ e1 '!' 'a' super_id super_id 'a']
		{
			lhs.msg = 'this is item1\n'
		}

	def e2 
		[]
		{
			print( 'old_id = ' trans_id_to '\n' )
			trans_id_to = typeid<super_id>
			print( 'new_id = ' trans_id_to '\n' )
		}

	def item2 
		msg: str

		[ e2 '!' 'a' super_id super_id 'a']
		{
			lhs.msg = 'this is item2\n'
		}


	def start 
		[item1 ';\n']
	|	[item2 ';\n']
		{
			match lhs [Item2:item2 ';\n']
			print( Item2.msg )
		}
end si

cons SuperId: si[]
parse S: si::start(SuperId)[stdin]
print_xml( S.tree )
print( '\n' )