Re: Lessons learned from the XML experiment

n a perfect world, we wouldn't put such constraints in our systems. However, I don't think that systems that have such constraints are "deeply broken". On the contrary, I think all human attempts to monitor, regulate, and systematize the world we live in rely on putting things into categories and labelling the categories as if they were unambiguous. Constraints saying that every company has two or more directors are typically imposed by legislators rather than IT people, and it's often IT people who have to cope with the fact that the constraints are broken (does the company cease to exist if the directors are killed in a plane crash?). We simply don't have the ability to design systems without such constraints, and a constraint language that enables us to be explicit about the constraints the system is imposing makes the system less broken than it would be if the constraints were there but not clearly articulated.