dolfin team mailing list archive

[Johan Hake <hake.dev@xxxxxxxxx>]

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

> 
> 
> Marco
>