The construction of a Map is abstract in Clojure. The concrete type of Map you get is not something you specify. This isn't related to the HAMT per say. So wha

The construction of a Map is abstract in Clojure. The concrete type of Map you get is not something you specify. This isn't related to the HAMT per say. So what I mean is Clojure will use an array backed map when you ask it to construct a small map, and it will give you a HAMT backed map when the map is large. This is true as well as you add elements to a map, Clojure might automatically promote the map from an array map to a HAMT as its size grows.