a

1 files changed, 32 insertions, 0 deletions

diff --git a/docs/history/17-o3-boundaries/code/examples/dump.zc b/docs/history/17-o3-boundaries/code/examples/dump.zc
new file mode 100644
index 0000000..6082213
--- /dev/null
+++ b/docs/history/17-o3-boundaries/code/examples/dump.zc
@@ -0,0 +1,32 @@
+// printing any struct with no printing code: the heap knows each object's
+// type, and reflection walks its fields
+struct person { *char name; int age; };
+struct item { *char name; int count; *person owner; };
+
+fn dump(p)
+{
+	let t = typeof_obj(p), i = 0;
+	if (!t) { puts("?"); return 0; }
+	tprint(t); puts(" { ");
+	while (i < tnfields(t)) {
+		let ft = tftype(t, i), v = p[tfoff(t, i)];
+		if (i) puts(", ");
+		puts(tfname(t, i)); puts(": ");
+		if (tkind(ft) == TY_PTR && telem(ft) == typeof(char)) { putc('"'); puts(v); putc('"'); }
+		else if (tkind(ft) == TY_PTR) { if (v) dump(v); else puts("null"); }
+		else putn(v);
+		i++;
+	}
+	puts(" }");
+	return 0;
+}
+fn main()
+{
+	*person ana = new(person);
+	ana.name = "ana"; ana.age = 30;
+	*item lamp = new(item);
+	lamp.name = "lamp"; lamp.count = 3; lamp.owner = ana;
+	dump(lamp); putc(10);
+	free(d*lamp);
+	return 0;
+}