struct undo

	lex
		ignore /( ' ' | '\t')+/
		literal `* `( `) `^ `;
		token NL /'\n'/
		token id /[a-zA-Z_]+/
	end

	struct foo
		Start: start
	end

	def item 
		[id]
	|	[`( item* `)]

	def start 
		Foo: foo
		[item* `; NL]

end

Undo: undo = new undo()

parse Input: undo::start(Undo)[ stdin ]

Input.Foo = new undo::foo()
Input.Foo->Start = Input
print( Input.Foo->Start )
###### IN ######
a b c ( d e ) f;
###### EXP ######
a b c ( d e ) f;