#
# Tokens
#

# Any single character can be a literal
lex start
{
	# Ignore whitespace.
	ignore /[ \t\n\r\v]+/

	# Open and close id
	token id /[a-zA-Z_][a-zA-Z0-9_]*/

	token open_paren /'('/ 
	{
		parse_stop NC: nested_comment( input )
		print( 'discarding: ' NC '\n' )
	}
}

#
# Token translation
#

lex nc_scan
{
	literal '(', ')'
	token nc_data /[^()]+/
}

def nc_item 
	[nc_data]
|	[nested_comment]

def nested_comment 
	['(' nc_item* ')']

def nested [id*]

global NestedParser: accum<nested> = 
	cons accum<nested>[]

lex two
{
	ignore /[ \t]+/
	token word /[a-zA-Z0-9/*+_\-]+/
	token stuff /[a-zA-Z0-9()/*+_\- ]+/
	literal '!', ';', '\n'

	def A1 []
		{ print( "A1\n" ) }

	def A2 []
		{ print( "A2\n" ) }

	def item
		[word]
		{
			send NestedParser [' ']
			send NestedParser [$r1]
			send NestedParser [' ']
		}
	|
		[stuff]
		{
			send NestedParser [' ']
			send NestedParser [$r1]
			send NestedParser [' ']
		}

	def two 
	[A1 item* '!' '\n']
	|
	[A2 item* ';' '\n']
}

Two: two = 
	parse two( stdin )

Nested: nested = NestedParser.finish()

print( '\n------------\n' )
print( ^Nested '\n' )
print( ^Two '\n' )