UBFa: module{	PATH:	con "/dis/lib/ubfa.dis"; 	UValue: adt {		pick{		Atom =>			name: string;		Int =>			value:	int;	# should have big as well?		String =>			s: string;		Binary =>			a: array of byte;		Tuple =>			a: cyclic array of ref UValue;	# tree		List =>			l: cyclic list of ref UValue;	# tree		Tag =>			name:	string;			o:	cyclic ref UValue;		} 		isatom:	fn(o: self ref UValue): int;		isstring:	fn(o: self ref UValue): int;		isint:		fn(o: self ref UValue): int;		istuple:	fn(o: self ref UValue): int;		isop: 	fn(o: self ref UValue, op: string, arity: int): int;		islist:		fn(o: self ref UValue): int;		isbinary:	fn(o: self ref UValue): int;		istag:	fn(o: self ref UValue): int;		text:		fn(o: self ref UValue): string;		eq:		fn(o: self ref UValue, v: ref UValue): int;		op:		fn(o: self ref UValue, arity: int): string;		args:		fn(o: self ref UValue, arity: int): array of ref UValue;		els:		fn(o: self ref UValue): list of ref UValue;		val:		fn(o: self ref UValue): int;		binary:	fn(o: self ref UValue): array of byte;		objtag:	fn(o: self ref UValue): string;		obj:		fn(o: self ref UValue): ref UValue;	}; 	init:	fn(bufio: Bufio);	readubf:	fn(input: ref Iobuf): (ref UValue, string);	writeubf:	fn(out: ref Iobuf, obj: ref UValue): int;	uniq:	fn(s: string): string; 	# shorthand	uvatom:	fn(s: string): ref UValue.Atom;	uvint:	fn(i: int): ref UValue.Int;	uvbig:	fn(i: big): ref UValue.Int;	uvstring:	fn(s: string): ref UValue.String;	uvbinary:	fn(a: array of byte): ref UValue.Binary;	uvtuple:	fn(a: array of ref UValue): ref UValue.Tuple;	uvlist:	fn(l: list of ref UValue): ref UValue.List;	uvtag:	fn(name: string, o: ref UValue): ref UValue.Tag;};