[CLJ-807] hash-maps print-dup as literal, thus can be read as array-maps

Fri, 29 Jul 2011 07:42:26 -0500

Per Rich in ~~CLJ-799~~: "The point of print-dup is type preservation"

user=> (hash-map :k :v)
{:k :v}
user=> (type *1)
clojure.lang.PersistentHashMap
user=> (binding [*print-dup* true] (print-str *2))
"{:k :v}"
user=> (read-string *1)
{:k :v}
user=> (type *1)
clojure.lang.PersistentArrayMap

The cause is due to RT.map conditionally creating an array-map if the size is within the PersistentArrayMap.HASHTABLE_THRESHOLD.

Clojure JIRA

[CLJ-807] hash-maps print-dup as literal, thus can be read as array-maps