The question of how to get a class by name comes up with some regularity on the ruby-talk and rails mailing lists. The first response is usually to use Object::const_get.
The response to that is that it doesn't handle classes within namespaces, e.g. Foo::Bar. I might argue that Object::const_get("Foo::Bar") should do the right thing and retrieve the value of Bar from the Foo class/module, but the fact of the matter is that it does not.
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