Question

我在VDM ++工具箱精简版上做VDM ++，下面是我的示例代码：

select t.*
from terms t
where t.price = (
    select min(t2.price)
    from terms t2
    where t2.d_start = t.d_start
        and t2.d_end = t.d_end
        and t2.departure_from = t.departure_from
)
order by t.d_start;

我试图运行代码。成功创建对象但是当我运行print getsubj（10,2）时，它返回错误运行时错误120：未知状态组件有人可以帮我提前谢谢你

Answer 1

在Overture / VDMJ中，此规范提供了两种类型检查错误。这些不出现在VDMTools中吗？

Error 3247: Symbol 'subjpersem' is not an updatable variable in 'Course' (test.vpp) at line 9:5
Error 3027: Operation returns unexpected type in 'Course' (test.vpp) at line 7:8
Actual: ()
Expected: study
Type checked 1 class in 0.119 secs. Found 2 type errors

VDM ++工具箱精简版上的未知错误

1 个答案: