lex start
{
token id /[a-zA-Z_][a-zA-Z0-9_]*/
literal '=', '<', '>', '/'
ignore /[ \t\n\r\v]+/
}
def attr
[id '=' id]
def open_tag
['<' id attr* '>']
def close_tag
['<' '/' id '>']
def tag
[open_tag item* close_tag]
def item
[tag]
| [id]
Tag: tag = parse tag( stdin )
# Style: List of literal text and types.
match Tag ["" item* ""]
# Style: Literal text with embedded lists of types.
match Tag "[item*]"
print( Val1 '\n' )
print( Val2 '\n' )