hash-maps print-dup as literal, thus can be read as array-maps

Question

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}}.

Answer 1

Comment made by: aaron

Rich: do you want a patch for this?

Answer 2

Comment made by: richhickey

Only if it important to someone, solves some problem.

Answer 3

Reference: https://clojure.atlassian.net/browse/CLJ-807 (reported by ataggart)