TODO

level 3

write test fuzzer

Make parse/match/parse* (anything which doesn't use self.obj) static
    or perhaps remove class and make purely functional.
more unit tests
implement T.empty
write better README. format in RST
    mention what it doesn't implement


broken level 3 tests:
    expr lexing is busted. can't do balanced parens.
    Probably need to use "rest" result from the scanner
    and do manual parsing.
    or. shudder. use the shitty regex the javascript uses.
    i.e. one big OR clause and suss out position arguments.