dolfin team mailing list archive

[Johan Hake <hake@xxxxxxxxx>]

On Friday 08 May 2009 15:09:44 Ola Skavhaug wrote:
> On Fri, May 8, 2009 at 1:53 PM, Johan Hake <hake@xxxxxxxxx> wrote:
> > On Friday 08 May 2009 13:41:37 Ola Skavhaug wrote:
> >> On Fri, May 8, 2009 at 11:40 AM, Anders Logg <logg@xxxxxxxxx> wrote:
> >> > On Fri, May 08, 2009 at 11:19:35AM +0200, Anders Logg wrote:
> >> >> We currently have two ways to print object data to the screen in
> >> >> DOLFIN:
> >> >>
> >> >>   cout << foo << endl;
> >> >>
> >> >>   foo.disp()
> >> >>
> >> >> The first of these prints a nicely-formatted one-liner:
> >> >>
> >> >>   [Mesh of topological dimension 2 with 121 vertices and 200 cells]
> >> >>
> >> >> The second prints more detailed information:
> >> >>
> >> >> Mesh data
> >> >> ---------
> >> >>
> >> >>   Mesh topology
> >> >>   -------------
> >> >>
> >> >>     Topological dimension: 2
> >> >>
> >> >>     Number of entities:
> >> >>
> >> >>       dim = 0: 121
> >> >>       dim = 1: 0
> >> >>       dim = 2: 200
> >> >>
> >> >>     ...
> >> >>
> >> >>     Connectivity:
> >> >>
> >> >>         0 1 2
> >> >>       0 - - -
> >> >>       1 - - -
> >> >>       2 x - -
> >> >>
> >> >>     Connectivity 2 -- 0:
> >> >>
> >> >>       0: 0 1 12
> >> >>       1: 0 11 12
> >> >>       2: 1 2 13
> >> >>       3: 1 12 13
> >> >>
> >> >> I'm thinking we could add a method named str() to all classes and
> >> >> then call str() both from LogStream<< and from __str__ in Python.
> >> >>
> >> >> Should the disp() method remain as it is today or should it be
> >> >> renamed to something else? Maybe print()?
> >> >
> >> > Or maybe info() is more logical, since calling foo.info() will result
> >> > in a string being sent to the info() function.
> >
> > This won't work for some of the linear algebra disp's as these rely on
> > the underlaying library. We can of course change this.
> >
> >> I like this idea. Will all dolfin classes inherit a pure virtual base
> >> class defining the str() method?
> >
> > Isn't the meaning of str() to return a string representation of the
> > object? Not print it. That should Info, Debug and its like do?
> >
> > With disp it is another case as I expect this function to print to the
> > screen if I do not tell it otherwise.
> >
> > Also _pure_ virtual is good. Haveing a base class that all classes should
> > inherit is not good as the public/protected base class methods are
> > unreachable for the derived classes when these are declared as shared_ptr
> > classes in swig.
>
> What do you mean? Pure virtual without a base class? Doesn't make
> sense in my head :)

Well, of course not. 

To make a long story short. Based on your (Olas) suggestions I have fixed this 
for Variable. Just reimplemented the member functions of Variable in its 
derived classes.

Johan

> >> If that's the case, we can, optionally, provide a stream to which the
> >> info is written, e.g., cerr, cout, or a stringstream from Python.
> >
> > Could this be done by
> >
> >  info(foo.str());
> >
> > and then redirect the output of info?
>
> This could be done in several ways, for instance through the parameter
> system or by a base class method a-la set_output(std::ostream&
> outstream); Following Anders, your solution would not enable the
> redirection of foo.info(), which is what I want. Being able to control
> this outside the library, that is in application space, is good.
>
> Ola
>
> > Johan
> >
> >> Ola
> >>
> >> > --
> >> > Anders
> >> >
> >> > -----BEGIN PGP SIGNATURE-----
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> >> > =qi/J
> >> > -----END PGP SIGNATURE-----
> >> >
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