The empty map literal is read as a different map each time
Description
As reported here (https://groups.google.com/forum/?hl=en#!topic/clojure-dev/n83hlRFsfHg), the empty map literal is read as a different map each time.
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user=> (identical? (read-string "{}") (read-string "{}"))
falseMaking the reader return the same empty map when it reads an empty map is expected to improve some memory efficiency, and also lead to consistency with the way other collection literals are read in.
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user=> (identical? (read-string "()") (read-string "()"))
true
user=> (identical? (read-string "[]") (read-string "[]"))
true
user=> (identical? (read-string "#{}") (read-string "#{}"))
trueCause: LispReader calls RT.map() with an empty array when it reads an empty map, and RT.map() in turn makes a new map unless its argument given is null.
Approach: make RT.map() return the same empty map when the argument is an empty array as well, not only when null
Patch: 0002-make-the-reader-return-the-same-empty-map-when-it-re.patch
Screened by: Alex Miller
Environment
None
Status
Assignee
Unassigned
Reporter
Shogo Ohta
Approval
Ok
Patch
Code
Fix versions
Affects versions
Release 1.6
Release 1.5
Priority
MajorConfigure