/* ===== 模块7：高级特性 =====
 * test15_defer — 延迟执行
 * 难度：3/5
 * 验证点：defer 语句、defer 块、多个 defer（逆序执行）、
 *         函数中 defer、块作用域 defer
 */
@extern(vm) fn vm_printf(fmt: *u8, ...) void;

fn with_cleanup() void {
    defer vm_printf("  inner defer\n");
    vm_printf("  inside with_cleanup\n");
}

fn main() i32 {
    vm_printf("--- defer test ---\n");

    /* defer 语句 */
    defer vm_printf("defer1\n");
    vm_printf("after defer1\n");

    /* defer 块 */
    defer {
        vm_printf("defer block\n");
    }
    vm_printf("after defer block\n");

    /* 函数内 defer */
    with_cleanup();
    vm_printf("after with_cleanup\n");

    /* 多个 defer 应逆序执行出作用域应该立刻执行，包括循环作用域 */
    {
        defer vm_printf("block defer last\n");
        defer vm_printf("block defer middle\n");
        defer vm_printf("block defer first (should print third)\n");
    }

    /* 多个 defer 应逆序执行 */
    defer vm_printf("defer last\n");
    defer vm_printf("defer middle\n");
    defer vm_printf("defer first (should print third)\n");

    vm_printf("--- defer test end ---\n");
    ret 0;
}