Repro:
;; print-method
user=> (binding [*print-level* 1]
(prn {:a 1 :b 2}))
{:a 1, :b 2}
nil
user=> (binding [*print-level* 1]
(prn {:a {:b 2}}))
{:a #}
nil
user=> (binding [*print-level* 1]
(prn [(clojure.lang.MapEntry. :a 1)
(clojure.lang.MapEntry. :b 2)]))
[# #]
nil
;; clojure.pprint
user=> (binding [*print-level* 1]
(clojure.pprint/pprint {:a 1 :b 2}))
{#, #}
nil
user=> (binding [*print-level* 1]
(clojure.pprint/pprint {:a {:b 2}}))
{#}
nil
user=> (binding [*print-level* 1]
(clojure.pprint/pprint
[(clojure.lang.MapEntry. :a 1)
(clojure.lang.MapEntry. :b 1)]))
[# #]
nil
The docstring for *print-level* says:
If an object is a collection and is at a level greater than or equal to the value bound to print-level, the printer prints '#' to represent it.
A map entry is a collection and in {:a 1, :b 2} is at a level equal to *print-level*, so I would expect prn to have the same output as clojure.pprint.
