namespace; include rt; // lists as [len, items...], items owned by the list .u mklist(n) { let l = rt.new(n + 1); l[0] = 0; return u*l; } fn push(.m l, .d item) { l[l[0] + 1] = d*item; l[0] = l[0] + 1; return 0; } fn sum(.m l) { let s = 0, i = 1; while (i <= l[0]) { s += l[i][0]; i++; } return s; } .u box(v) { let b = rt.new(1); b[0] = v; return u*b; } fn consume(.d b) { return b[0]; } fn main() { let base = rt.live_objects(); { let l = mklist(8); // u from mklist arrives m*here let i = 0; while (i < 5) { let b = box(i * 10); // m in the loop body d*b; // give it down push(l, b); i++; } rt.put_n(sum(l)); rt.put_c(' '); rt.put_n(rt.live_objects() - base); rt.put_c(' '); // list + 5 boxes } rt.put_n(rt.live_objects() - base); rt.put_c(' '); // freed at the block's end, children too // u handed up one block by assignment, and as a block value let outer; { let t = box(7); u*t; outer = t; } let v = { let w = box(8); u*w }; rt.put_n(outer[0] + v[0]); rt.put_c(' '); // d given away to a callee let g = box(99); rt.put_n(consume(d*g)); rt.put_c(' '); // containers: child takes its parent's tag let p = rt.new(2), c = rt.new(1); c[0] = 5; p[0] = c; p[1] = rt.new(3); rt.put_n(p[0][0]); rt.put_c(' '); rt.put_n(rt.live_objects() - base); rt.put_c(10); return 0; }