/* ===== 模块7：高级特性 =====
 * test16_methods — 类型关联方法
 * 难度：3/5
 * 验证点：struct 方法、enum 方法、self 参数自动填充、方法调用
 */
@extern(vm) fn vm_printf(fmt: *u8, ...) void;

type Point = struct {
    x: i32,
    y: i32,

    fn init(x: i32, y: i32) Point {
        ret Point { .x = x, .y = y };
    }

    fn dump(self: *Point) void {
        vm_printf("Point(%d, %d)\n", self.x, self.y);
    }
}

type Expr = enum {
    Int: i32,
    Add: struct { left: *Expr, right: *Expr },

    fn eval(self: *Expr) i32 {
        match self {
            .Int(val) => ret val,
            .Add(left, right) => ret eval(left) + eval(right),
        }
        ret 0;
    }
}

fn main() i32 {
    /* struct 方法调用 */
    var p: Point = Point.init(3, 4);
    p.dump(&p);

    /* enum 方法 + match */
    var expr_l := Expr { .Int = 3 };
    var expr_r := Expr { .Int = 4 };
    var expr := Expr { .Add = { .left = expr_l, .right = expr_r } };
    var result := expr.eval(&expr);
    vm_printf("eval result: %d\n", result);
    if result != 7 { ret 1; }

    ret 0;
}