context rubyhere
	rl ident_pattern /[a-zA-Z_][a-zA-Z_0-9]*/
	rl number_pattern /[0-9]+/

	lex
		ignore /[ \t\n]+/
		token id /ident_pattern/
		token number /number_pattern/
		literal `<< `* `, `( `) `!
	end

	HereId: str

	token rest_of_line /[^\n]*'\n'/

	lex 
		ignore /[ \t\n]+/
		token here_id
			HereData: here_data
			/ident_pattern/
			{
				# Take the text of the here_id from the input stream.
				HereId = input->pull( match_length )

				# Get the data up to the rest of the line.
				parse_stop ROL: rest_of_line(this input)[]

				# Parse the heredoc data.
				parse_stop HereData: here_data(this input)[]

				# Push the rest-of-line data back to the input stream.
				input->push( $ROL )

				# Send the here_id token. Attach the heredoc data as an attribute.
				input->push( make_token( typeid<here_id>, HereId, HereData ) )
			}
	end

	lex 
		token here_close_id 
			/ ident_pattern '\n' /
			{
				if match_text == HereId + '\n' {
					input->push( make_token( 
						typeid<here_close_id>,
						input->pull( match_length ) ) )
				}
				else 
					input->push( make_token( typeid<here_line>, input->pull(match_length) ) )
			}

		token here_line
			/ [^\n]* '\n' /
	end

	def here_data
		[here_line* here_close_id]

	def heredoc
		[`<< here_id]

	def primary
		[id]
	|	[number]
	|	[heredoc]

	def arglist
		[primary arglist_more*]

	def arglist_more
		[`, primary]

	def call
		[id `( arglist? `)]

	def statement
		[primary]
	|	[call]

	token foobar /any+/

	def item
		[statement `!]
	|	[foobar]

	def start 
		[item*]
end # rubyhere

RubyHere: rubyhere = new rubyhere()

parse S: rubyhere::start(RubyHere)[ stdin ]

print( xml(S) )
print('\n')
##### IN #####
print( <<DATA1, more, <<DATA2, 99 )
"&^#(@ almost
!arbitrary text!
DATA1
hello
world
DATA2
!
print( <<DATA1, more, <<DATA2, 99 )
"&^#(@ almost
!arbitrary text!
DATA1
hello
world
DATA2
# error here
##### EXP #####
<rubyhere::start><rubyhere::_repeat_item><rubyhere::item><rubyhere::statement><rubyhere::call><rubyhere::id>print</rubyhere::id><rubyhere::_literal_000d>(</rubyhere::_literal_000d><rubyhere::_opt_arglist><rubyhere::arglist><rubyhere::primary><rubyhere::heredoc><rubyhere::_literal_0007>&lt;&lt;</rubyhere::_literal_0007><rubyhere::here_id>DATA1</rubyhere::here_id></rubyhere::heredoc></rubyhere::primary><rubyhere::_repeat_arglist_more><rubyhere::arglist_more><rubyhere::_literal_000b>,</rubyhere::_literal_000b><rubyhere::primary><rubyhere::id>more</rubyhere::id></rubyhere::primary></rubyhere::arglist_more><rubyhere::arglist_more><rubyhere::_literal_000b>,</rubyhere::_literal_000b><rubyhere::primary><rubyhere::heredoc><rubyhere::_literal_0007>&lt;&lt;</rubyhere::_literal_0007><rubyhere::here_id>DATA2</rubyhere::here_id></rubyhere::heredoc></rubyhere::primary></rubyhere::arglist_more><rubyhere::arglist_more><rubyhere::_literal_000b>,</rubyhere::_literal_000b><rubyhere::primary><rubyhere::number>99</rubyhere::number></rubyhere::primary></rubyhere::arglist_more></rubyhere::_repeat_arglist_more></rubyhere::arglist></rubyhere::_opt_arglist><rubyhere::_literal_000f>)</rubyhere::_literal_000f></rubyhere::call></rubyhere::statement><rubyhere::_literal_0011>!</rubyhere::_literal_0011></rubyhere::item><rubyhere::item><rubyhere::foobar>print( &lt;&lt;DATA1, more, &lt;&lt;DATA2, 99 )
"&amp;^#(@ almost
!arbitrary text!
DATA1
hello
world
DATA2
# error here
</rubyhere::foobar></rubyhere::item></rubyhere::_repeat_item></rubyhere::start>