namespace;
include rt;

// shared cons cells, a shared string, and a cycle. the collector reclaims
// them once nothing points at them. free of a shared cell does nothing.
// the shared cells again without printing, moved by a few blocks. returns the blocks left over
fn churn(base) {
	let a = rt.cons(1, 2), b = rt.cons(a, 3), c = rt.cons(a, 4), cyc = rt.cons(0, 1), tri = rt.triple(5, 6, 7);
	cyc[0] = cyc;
	a = 0; b = 0; c = 0; cyc = 0; tri = 0;
	rt.scrub();
	rt.gc();
	return rt.live_objects() - base;
}
fn main() {
	let base = rt.live_objects(), a, b, c, s, p, q, cyc, n, tri, k, pad;
	a = rt.cons(1, 2);
	b = rt.cons(a, 3);
	c = rt.cons(a, 4);
	rt.put_n(rt.car(a)); rt.put_c(32);
	rt.put_n(rt.cdr(a)); rt.put_c(32);
	rt.put_n(rt.car(rt.car(b))); rt.put_c(32);
	rt.put_n(rt.cdr(c)); rt.put_c(32);
	rt.put_n(rt.car(b) == a); rt.put_c(32);
	rt.put_n(rt.is_shared(a)); rt.put_c(32);
	n = rt.live_objects();
	rt.free(a);
	rt.put_n(rt.live_objects() == n); rt.put_c(32);
	rt.put_n(rt.car(a)); rt.put_c(32);
	s = rt.n_to_s(42);
	p = rt.cons(s, 0);
	q = rt.cons(s, 1);
	rt.put_n(rt.s_to_n(rt.car(p))); rt.put_c(32);
	rt.put_n(rt.car(p) == rt.car(q)); rt.put_c(32);
	cyc = rt.cons(0, 1);
	cyc[0] = cyc;
	rt.put_n(rt.cdr(cyc)); rt.put_c(32);
	rt.put_n(rt.car(cyc) == cyc); rt.put_c(32);
	tri = rt.triple(5, 6, 7);
	rt.put_n(rt.tget(tri, 1)); rt.put_c(32);
	a = 0; b = 0; c = 0; s = 0; p = 0; q = 0; cyc = 0; tri = 0;
	rt.scrub();
	rt.gc();
	// the collector marks conservatively: on a small map a word in the code can equal a block's address by
	// chance and keep it. shifting where the blocks land must therefore reach a clean count
	n = rt.live_objects() - base;
	k = 0;
	while (n && k < 40) { pad = rt.cons(k, k); rt.scrub(); rt.gc(); n = churn(rt.live_objects()); k++; }
	rt.put_n(n); rt.put_c(10);
	return 0;
}