context si
	lex
		literal `! `a 

		token SEMI_NL /';\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 SEMI_NL]
	|	[item2 SEMI_NL]
		{
			match lhs [Item2:item2 ';\n']
			print[ Item2.msg ]
		}
end # si

SuperId: si = new si()
parse S: si::start(SuperId)[stdin]
print( xml( S ) )
print( '\n' )
##### IN #####
!a b b a;
##### EXP #####
old_id = 0
new_id = 9
old_id = 0
new_id = 8
this is item2
<si::start><si::item2><si::e2></si::e2><si::_literal_0001>!</si::_literal_0001><si::_literal_0003>a</si::_literal_0003><si::super_id>b</si::super_id><si::super_id>b</si::super_id><si::_literal_0003>a</si::_literal_0003></si::item2><si::SEMI_NL>;
</si::SEMI_NL></si::start>