Re: [myhdl-list] Error in Intbv class?

[Samuele D. <sm...@gm...>]

Hello, Last message was empty, my mistake.

On Thu, Mar 3, 2016 at 2:10 PM, Samuele Disegna <sm...@gm...> wrote:

>
>
> On Thu, Mar 3, 2016 at 1:14 PM, Forumulator Bing <for...@gm...>
> wrote:
>
>> Hello,
>>
>> I may have found a potential bug in intbv:
>>
>> >>> a=intbv(5)[4:0]
>> >>> a[6:0]=20
>> Traceback (most recent call last):
>>   File "<stdin>", line 1, in <module>
>>   File "/usr/local/lib/python3.4/dist-packages/myhdl/_intbv.py", line
>> 180, in __setitem__
>>     self._handleBounds()
>>   File "/usr/local/lib/python3.4/dist-packages/myhdl/_intbv.py", line 77,
>> in _handleBounds
>>     (self._val, self._max))
>> ValueError: intbv value 20 >= maximum 16
>> >>> a
>> intbv(20)
>>
>> It gives a ValueError, but still sets the value of a to 20. Would this be
>> considered a bug since an exception is thrown?
>>
>>
> From what I see on myhdl code min/max bounds handling is done later than
assignment and it seems independent.
Therefore I would say it is not a bug. We could document this behaviour.
Is it possible to subclass the exception to a documented ValueBoundError
that define the behaviour?

You can find the related code at
https://github.com/jandecaluwe/myhdl/blob/master/myhdl/_intbv.py
def __setitem__(self, key, val):

Regards