dolfin team mailing list archive

[Martin Sandve Alnæs <martinal@xxxxxxxxx>]

On 4 September 2012 10:49, Johan Hake <hake.dev@xxxxxxxxx> wrote:
> On 09/04/2012 10:00 AM, Marco Morandini wrote:
>> On 09/03/2012 06:56 PM, Johan Hake wrote:
>>> Marco!
>>>
>>> This is caused by the new automatic parsing of dependencies for
>>> compiled_modules in Python. It was added so a minimum of dependencies
>>> are dragged into the compilation, reducing the compilation time
>>> considerably.
>>
>> Yes, I've seen you commits; they really reduce the compilation time.
>> Thanks!
>
> dolfin.h drags in a lot of types...
>
>>> I do agree that your case should be supported in a better way than
>>> adding it as a hack, as you did. Another hack is to introduce a dummy
>>> public dependency:
>>
>> ....
>>
>>>
>>> What we probably need is to expose some more compile options to the
>>> Expression interface so you can do:
>>>
>>>    Expression(cppcode_d1, element=DGe, \
>>>               system_headers=["dolfin/fem/GenericDofMap.h"])
>>>
>>> Other opinions?
>>
>>
>> I think that the dolfin namespace should be automatically dealt with
>> for code like
>>
>> p = Expression('x[0] + x[1]')
>>
>> but it should be the user's responsibility to deal with it
>> whenever this idiom
>>
>> delta1 = Expression(cppcode_d1, element=DGe)
>>
>> is used.
>>
>> I.e.
>>
>> p = Expression('x[0] + x[1]')
>>
>> should automatically generate
>>
>> namespace dolfin
>> {
>> class Expression_121446782cdb69f97c3b9ff77a93499b: public Expression
>> {
>> public:
>>   Expression_121446782cdb69f97c3b9ff77a93499b():Expression()
>>   {  }
>>   void eval(dolfin::Array<double>& values, const dolfin::Array<double>&
>> x) const
>>   { values[0] = x[0] + x[1]; }
>> };
>> }
>>
>> as it does right now,
>>
>> but for
>>
>> self.delta1 = Expression(cppcode_d1, element=DGe)
>>
>> the (supposedly proficient) user should explicitly
>> enter the namespace:
>>
>> cppcode_d1 = """
>> #include "whatever_must_be_additionally_included_and_is_not_detected"
>> namespace dolfin
>> {
>> class Delta1 : public Expression
>> {
>>  ....
>> }  //end class Delta1
>> }; //end namespace dolfin"""
>>
>> without having it auto-magically opened and closed.
>>
>> I don't know if this is possible, thought. It would perhaps break a lot
>> of user code but, on the other side, a lot of user code out there is
>> perhaps broken right now precisely because of this problem, and you
>> don't see any complaint because few users work with the trunk ....
>
> Might be. I have not thought of automatically adding namespace as a
> problem before. I suppose adding dolfin namespace automatically is a bit
> surprising for the power users. Especially if one wants to use other
> namespaces.
>
> We could use a regexp to check if a namespace is already added, and
> adding it if there isn't one?
>
> I still think it would be a good idea to add more powerful link and
> include options to the compiled expression interface. This would fix
> your case and others who wants more powerful external libraries.
>
> Johan

I don't understand why the user-defined class is placed in the dolfin
library namespace in the first place?

Martin