CondMod: module {
	PATH: con "condmod.dis";
	init: fn(nil: ref Draw->Context, argv: list of string);

	Cond: adt[ValT] for {
		ValT => less: fn(n: ValT, m: ValT): int;
	} {
		name: string;
		min, max: ref ValRef->Val[ValT];

		# higher-level convenience constructors
		range: fn[ValT](name: string, min, max: ValT): ref Cond
		for {
			ValT => less: fn(n: ValT, m: ValT): int;
		};
		equal: fn[ValT](name: string, val: ValT): ref Cond
		for {
			ValT => less: fn(n: ValT, m: ValT): int;
		};
		zero: fn[ValT](name: string): ref Cond
		for {
			ValT => less: fn(n: ValT, m: ValT): int;
		};
	};
};