On Fri, 2010-08-13 at 17:48 -0600, John Doty wrote: > On Aug 13, 2010, at 5:39 PM, DJ Delorie wrote: > > > > >> So why not just have properties, and sets of properties. > > > > A set of properties *is* a class, if you apply the same set of > > properties to many nets. Why not let the user pre-define such > > classes, to make their work easier? > > I suggested that. > > I also suggested considering a set of properties to be a property, not > a class. Or did you not understand "flattened union". Maybe that was > too obscure. >
In my simple mind I consider a set of properties a class. But of course we can call it again a property. Or we can use no sets at all, just single properties. So instead of class/propertyset power one has to specify "width>25mil, clearance=12mil, color=blue, ...". This is OK, but I think sets/classes make it easier for users and may save space in data files, and may make changes easier. (I know that we can currently assign attributes to nets in gschem, but my impression is that all touching line segments are one net, so we do not have subnets. Which we should have. And we should have color support, a way to see fast which nets segments are "High Current"... So some internal modification of gschem is necessary.) Indeed, all which we do is assign a special name/label to some subnets, like "power_class" or "bypass_class". We do not have to define inside of gschem what this really means, like "tracewidth=25mil" and "clearance=12mil". We can define this only in PCB. But I think it is more intuitive and practical if we can define such sets already in gschem and transfer that information to PCB (where we may change it if necessary). Best regards Stefan Salewski _______________________________________________ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user