#$ Just some stress test with polymorphic functions. (expects defined Tuple2 type)
# ((1, True), ())
# ((420, 1337), True)
# True
# 420
# 1337
# 123
# True
# False


fn fst (t)
	case t
		Tuple2(l, r)
			return l

fn snd (t)
	case t
		Tuple2(l, r)
			return r

fn swap (t)
	case t
		Tuple2(l, r)
			return Tuple2(r, l)


fn print-tuple (tup Tuple2 a b) -> Unit <= Str a, Str b
	case tup
		Tuple2(l, r)
			println(l)
			println(r)

	return


t = Tuple2(Tuple2(Tuple2(1, True), Unit), Tuple2(Tuple2(420, 1337), True))
print-tuple(t)

# get dat bool
println(snd(fst(fst(t))))

# now, try to reach 420
println(fst(fst(snd(t))))

# hard mode
t' = swap(t)
println(snd(fst(snd(t))))  # owo what is this



fn map-snd (t, f)
	case t
		Tuple2(l, r)
			return Tuple2(l, f(r))

fn map-fst (t, f)
	case t
		Tuple2(l, r)
			return Tuple2(f(l), r)

fn const (a)
	return fn b: a


t'' = map-snd(t, const(123))
println(snd(t''))


fn negate (b)
	case b
		True
			return False

		False
			return True

t''' = map-snd(t, fn (a): map-snd(a, negate))
println(snd(snd(t)))
println(snd(snd(t''')))