This, and before 1.3 you were supposed to define a constructor function yourself. I'm pretty sure that was somewhere in the documentation. Or in the clojure.org

This, and before 1.3 you were supposed to define a constructor function yourself. I'm pretty sure that was somewhere in the documentation. Or in the clojure.org/datatypes. Or in some mailing list post that I red. The Clojure documentation is a mess.