[myhdl-list] Re: VCD viewer ?

[Jean D. <jea...@un...>]

Jan Decaluwe a écrit :
> Jean Demartini wrote:
> 
>> I'm a little newbie in Python and some Python idiom's are a little 
>> puzzling. Then my question:
>>
>> Why an enum variable is not a true class testable by 
>> isinstance(..,Enum) ? this will simplify the catching of enum 
>> variables in _Signal.py.
>>
>> Jean
> 
> 
> I see your point, and I agree.
> 
> Probably the "idiom" that puzzles you is the usage of the "nested"
> classes EnumItem and Enum in function enum in module _enum.py.
> This looks rather strange: my intention was to make sure these
> auxiliary classes are not directly usable by a user. But there
> are other ways to achieve that, such as giving them a "private"
> name, starting with underscore.
> 
> You are correct in stating that these objects should be
> indentifiable by an instance check. This can be achieved easily
> by using a "dummy" parent class, whose sole purpose is to be
> subclassable by the actual (private) Enum class. This can be
> done as follows (untested):
> 
> In _enum.py, create a new EnumType class at the module level:
> 
>     class EnumType(object):
>         pass
> 
> Subclass the private Enum class from EnumType instead of object:
> 
>     class Enum(EnumType):
>         ....
> 
> Make the EnumType class visible in __init__.py:
> 
>     from _enum import EnumType
> 
> Now you can use it with:
> 
>    from myhdl import EnumType
> 
> and things like isinstance(obj, EnumType) should work.
> 
> Regards,
> 
> Jan
> 
Thanks for all this information.
I will modify _Signal.py and _traceSignals.py accordingly trying to 
maintain compatibility between GTKwave and WaveVCD.

I will then inform the forum of the progress.

Jean