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1 files changed, 32 insertions, 0 deletions

diff --git a/examples/lists.zc b/examples/lists.zc
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index 0000000..02059f3
--- /dev/null
+++ b/examples/lists.zc
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+// ownership in practice: a list owns its boxes. nothing here calls free;
+// everything is released at the end of the block that owns it.
+.u box(v) { let b = new(1); b[0] = v; return u*b; }
+.u mklist(cap) { let l = new(cap + 1); l[0] = 0; return u*l; }
+// item m*arrives (it was given down), and goes d*on into the borrowed list
+fn push(.m l, .d item) { l[l[0] + 1] = d*item; l[0] = l[0] + 1; return 0; }
+fn show(.m l) {
+	let i = 1;
+	put_c('[');
+	while (i <= l[0]) { if (i > 1) put_c(' '); put_n(l[i][0]); i++; }
+	put_c(']');
+	return 0;
+}
+.u squares(n) {
+	let l = mklist(n), i = 0;
+	while (i < n) {
+		let b = box(i * i);
+		push(l, d*b);
+		i++;
+	}
+	return u*l;
+}
+fn main() {
+	let before = live_objects();
+	{
+		let l = squares(6);
+		show(l); put_c(10);
+		put_s("live: "); put_n(live_objects() - before); put_c(10);
+	}
+	put_s("after the block: "); put_n(live_objects() - before); put_c(10);
+	return 0;
+}