// 闭包测试 — 非捕获 lambda + 变量捕获
fn make_adder(base: i64) -> i64 {
    let adder = fn(x: i64) -> i64 { return x + base; };
    return adder(50);
}

fn main() -> void {
    // 测试1: 非捕获 lambda
    let double = fn(x: i64) -> i64 { return x * 2; };
    print_i64(double(21));  // 42

    // 测试2: 捕获单个变量
    let base = 100;
    let add = fn(x: i64) -> i64 { return x + base; };
    print_i64(add(50));  // 150

    // 测试3: 捕获多个变量
    let a = 10;
    let b = 20;
    let sum3 = fn(x: i64) -> i64 { return x + a + b; };
    print_i64(sum3(5));  // 35

    // 测试4: 函数内创建闭包
    let r = make_adder(200);
    print_i64(r);  // 250
}