re-blessing doesn't mean you violate parent-knowledge behavior. In fact, Policy, Manifest, and/or Factory classes would be a better way of doing this.

1. Create a file object.
2. The file object, during construction, finds out it's a directory.
3. The file object will then either:
   • Ask the Factory to for the classname to rebless to
   • Give itself to the Factory and asks to be reblessed

The factory or policy or manifest should be the one that maintains that knowledge and how to transform.

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We are the carpenters and bricklayers of the Information Age.

Don't go borrowing trouble. For programmers, this means Worry only about what you need to implement.