lex
	ignore /space+/
	literal `* `( `)
	token id /[a-zA-Z_]+/
end

def item1 
	[id]
|	[`( item1* `)]

def item2
	[id]
|	[`( item2* `)]

def start 
	[item1*]

StartParser1: parser<start> = new parser<start>()
StartParser2: parser<start> = new parser<start>()
StartParser3: parser<start> = new parser<start>()

parse Item1: item1 "b
parse Item2: item2 "b

# Success.
send StartParser1
	"a [Item2] c d\n" eos

# Success.
send_tree StartParser2
	"a [Item1] c d\n" eos

# Failure.
send_tree StartParser3
	"a [Item2] c d\n" eos

print[ @StartParser1->tree ]
print[ @StartParser2->tree ]
print[ @StartParser3->tree "\n" ]
######### EXP #########
a b
 c d
a b
 c d
NIL