How can I leak memory in Clojure?

Question

For a presentation at the Bay Area Clojure Meetup on Thursday I am compiling a list of ways to leak memory in Clojure.

So far I have:

• hold onto the head of an infinite sequence
• creating lots of generic classes by calling lambda in a loop (is this still a problem)
• holding a reference to unused data
• ...

What else?

Answer 1

By keeping a reference to a seq on a large collection. eg:

(drop 999990 (vec (range 1000000))) 

returns a seq of ten elements that holds a reference to the whole vector!