On 08/09/2012 09:18 AM, Miguel Angel Ajo Pelayo wrote: > >From what I saw yesterday on my investigation, we're doing that correctly, > we fetch the .h, and as the .h has the enum, swig implement that enum values > in python, > > but if you look at them carefully (under the swig code), you will see that it > internally > uses "int" > for that. > > So where you are saying obj.SetLayer(LAYER_15) > one could say obj.SetLayer(15) > > and no typecheck will show up, > > anyway, the problem could appear if an intrepid user does: > > obj.SetLayer(45) > > > That will under the hood in our C++, because swig will accept it (int is the > internal > representation used for enums values), > and if somebody does layer[n] somehow with n> elementsOf(layer) , we will > have trouble.
Yes, I understood all this already. C++ has type checking, this is something that the project originators came to rely on. Jean-Pierre, et. al. It was considered when adopting the language. Throwing exceptions from C++ for bad arguments is visual noise that the C++ adopter did not bargain for when he chose the language. It was also not bargained for when accepting SWIG to tag along. It is a cost and an imposition to throwing these exceptions, visually, and in maintenance. C++ type checking an enums were designed to prevent the need for this. I think as you move away from enums into ints as parameters, then C++ has no inherent compile time protections, so this is not so black and white there. But throwing "bad argument exceptions" from every C++ function callable from python was not part of the original bargain. I do not see a similar support infrastructure within wxWidgets, yet wxPython seems to work adequately. Keep thinking. _______________________________________________ Mailing list: https://launchpad.net/~kicad-developers Post to : [email protected] Unsubscribe : https://launchpad.net/~kicad-developers More help : https://help.launchpad.net/ListHelp
