lex
	token c_single_lit /( 'L'? "'" ( [^'\\\n] | '\\' any )* "'" )/
	token c_double_lit /( 'L'? '"' ( [^"\\\n] | '\\' any )* '"' )/

	token sym / ';' | ',' | '=' | '(' | ')' | ':' | '&' | '*' |
		'[' | ']' | '~' | '+' | '-' | '/' | '<' | '>' | '|' | 
		'^' | '%' | '!' | '?' | '.' | '#'/

	# Identifiers
	token c_id /( [a-zA-Z_] [a-zA-Z0-9_]* )/

	# Comments and whitespace.
	token comm_c /( '/*' (any | '\n')* :>> '*/' )/
	token comm_cxx /( '//' any* :> '\n' )/
	token ws /( any - 33..126 )+/
end

def c_token
	[c_single_lit]
|	[c_double_lit]
|	[sym]
|	[c_id]
|	[comm_c]
|	[comm_cxx]
|	[ws]

def c_token_list
	[c_token c_token_list]
|	[c_token]

# Can parse this, use ful for single constructs.
def c
	[c_token*]

literal '%%'

lex
	literal '{', '}'
	literal 'protocol', 'client', 'server', 'port', 'by', 'tcp', 'udp'
	token id /[A-Za-z_][A-Za-z_0-9]*/
	token number /[0-9]+/

	ignore /'/*' any* :>> '*/'/
	ignore /[ \t\r\n]+/
end

def tcp_by_port
	['tcp' 'by' 'port']

def udp_by_port
	['udp' 'by' 'port']

def attribute
	['client' id]
|	['server' id]
|	['port' number]
|	['udp' id]
|	[tcp_by_port]
|	[udp_by_port]

def tcp_protocol
	['tcp' 'protocol' id '{' attribute* '}']

def udp_protocol
	['udp' 'protocol' id '{' attribute* '}']

def protocol
	[tcp_protocol]
|	[udp_protocol]

def program
	[c '%%' protocol*]

alias output accum<c>

def port 
	Port: int 
	Protocol: str 
	[]

# Parse the input.
parse PP: program[ stdin ]
P: program = PP.tree

Output: output Output = construct output []

# Take off the leading C from the input file and send it out.
match P [C: c '%%' protocol*]

Output << [$C]
Output <<
	"#include <assert.h>
	"

print( Output.finish() )